A Brief Sourcebook of the History of Philosophy

The Thinker (1880) by Auguste Rodin located at the Musée Rodin in Paris / Photo by Andrew Horne, Wikimedia Commons

By Dr. James Fieser / 04.12.2009
Professor of Philosophy
University of Tennessee, Martin


The following is a collection of famous quotations from the most influential philosophers since the time of the earliest Greek philosophers up to the eighteenth century. While it is intended as a supplement to Philosophy through the Ages: A Short History, and parallels the chronology of the philosophers presented there, it might also be useful as an independent resource. Most of the well-known philosophers were prolific authors, composing thousands of pages material on a wide range of issues. While we might easily associate philosophers with their beloved theories—such as Plato’s allegory of the cave or Descartes’ view of the pineal gland—it is sometimes less easy to quickly locate their most famous passages from within the labyrinth of their published works. The selections below present precisely those philosophical discussions which helped immortalized their authors.


Ancient Greek philosopher from Miletus who held that water is the basic stuff.


Of the first philosophers, most thought that the principles which pertained to the qualities of matter were the only principles of all things…. Yet they did not all agree as to the number and the nature of these principles. Thales, the founder of this type of philosophy, said the principle is water (for which reason he declared that the earth rests on water). Perhaps he got this notion from seeing that the nutrition of all things is moist, and that heat itself is generated from the moist and kept alive by it (and that from which they come to be is a principle of all things). Perhaps he also got his notion from the fact that the seeds of all things have a moist nature, and that water is the origin of the nature of moist things. [Aristotle, Metaphysics, 1.3]

ANAXIMANDER (c. 610-545 BCE)

Ancient Greek philosopher from Miletus who held that the boundless (apeiron) is the source of everything.

The Unbounded

He held that that the principle and primary element of all things was the unbounded, giving no exact definition as to whether he meant air or water, or anything else. He said that while the parts were susceptible of change, the whole was unchangeable. [Diogenes Laertius]

Anaximander of Miletus, son of Praxiades, a fellow-citizen and associate of Thales, said that the material cause and first element of things was the Infinite, he being the first to introduce this name of the material cause. He says it is neither water nor any other of the so-called elements, but a substance different from them which is infinite, from which arise all the heavens and the worlds within them. [Theophrastus, quoted by Simplicius, Commentary on Aristotle’s Physics]

[According to Anaximander,] there is a body distinct from the elements, the infinite, which is not air or water, in order that the other things may not be destroyed by their infinity. The elements are in opposition to each other: air is cold, water moist, and fire hot. Therefore, if any one of them were infinite, the rest would have ceased to be by this time. Accordingly he said that what is infinite is something other than the elements, and from it the elements arise. [Aristotle, Physics, 3.3]

ANAXIMENES (c. 585-525 BCE)

Ancient Greek philosopher from Miletus who held that the condensed and expanded air is the source of everything.


Anaximenes of Miletus, who had been an associate of Anaximander, said, like him, that the underlying substance was one and infinite. He did not, however, say it was indeterminate, like Anaximander, but determinate; for he said it was Air. It differs in different substances in virtue of its rarefaction and condensation. In its thinnest state it comes to be; being condensed it becomes wind, then cloud, and when still further condensed it becomes water, then earth, then stones, and the rest of things comes to be out of these. [Theophrastus, quoted by Simplicius, Commentary on Aristotle’s Physics]

PYTHAGORAS (c.570–c.497 BCE)

Ancient Greek philosopher from Samos who emphasized the mathematical relations that underlie reality.


Pythagoras declared that the soul is immortal, then that it changes into other kinds of animals. In addition, the things that happen recur at certain intervals, and nothing is absolutely new. Also, all things that come to be alive must be thought akin. Pythagoras seems to have been the first to introduce these opinions into Greece. [Porphyry, Life of Pythagoras, 19]


Do not stir the fire with a knife. Rub out the mark of a pot in the ashes. Do not wear a ring. Do not have swallows in the house. Spit on your nail parings and hair trimmings. Abstain from eating beans. Abstain from eating living things. Roll up your bedclothes on rising and smooth out the imprint of the body. Do not urinate facing the sun.

The Tetractys

The tetractys is a certain number, which being composed of the four first numbers produces the most perfect number, ten. For one and two and three and four come to ten. This number is the first tetractys, and is called the source of ever flowing nature. This is because, according to them, the entire cosmos is organized according to harmony, and harmony is a system of three concords: the fourth, the fifth, and the octave. And the proportions of these three concords are found in the aforementioned four numbers. [Sextus Empiricus, Against the Mathematicians, 7.94-95]

HERACLITUS (c. 540–c. 480 BCE)

Ancient Greek philosopher from Ionia who emphasized that an ever-changing world is sustained and given a kind of permanence through the logos.


Cold things become warm, and what is warm cools; what is wet dries, and the parched is moistened.

You cannot step twice into the same rivers; for fresh waters are ever flowing in upon you. It scatters and it gathers; it advances and retires.

The Logos

It is wise to listen, not to me, but to the Logos, and to agree that all things are one.

Though this Logos is true always, yet people are as unable to understand it both when they hear it for the first time and when they have heard it at all again. For, though all things come into being in accordance with the Logos, people seem as if they had no experience of it, when they make meet with words and actions that I establish, dividing each thing according to its kind and showing how it truly is. As for the rest of the people, they do not know what they are doing when awake, just as they forget what they do once asleep.

The ordered universe, which is the same for all, was not made by one of gods or by humans. Rather, always was, is now, and forever will be an ever-living fire, ignited in measure, and extinguished in measure.

XENOPHANES (c. 570–c.478 BCE)

Ancient Greek philosopher who satirized anthropomorphic conceptions of the gods, particularly as held by Homer, Hesiod and Pythagoras.


Homer and Hesiod have ascribed to the gods all things that are shameful and disgraceful among mortals, such as theft, adultery and the deception of one another.

Mortals suppose that the gods are born and have clothes and voices and shapes like their own.

If oxen and horses or lions had hands, and could paint with their hands, and produce works of art as people do, horses would paint the forms of the gods like horses, and oxen like oxen, and make their bodies in the image of their several kinds.

The Ethiopians make their gods black and snub-nosed; the Thracians say theirs have blue eyes and red hair.


God is one, the greatest among gods and humans, who neither in form nor in thought is like mortals.

He sees all over, thinks all over, and hears all over. But without toil he sways all things by the thought of his mind.

He always remains in the same place, without moving at all; nor does it suit him to go about here or there.

There never was nor will be a person who has certain knowledge about the gods and about all the things I speak of. Even if he should chance to say the complete truth, yet he himself does not know that it is so. But all may have their opinions.

PARMENIDES (fl. c. 450 BCE)

Ancient Greek philosopher from Elea who argued that every day perception of the world is wrong and all reality is the One, that is, a single, undifferentiated and unchanging thing.

Path to Truth

There are only two ways of inquiry that can be thought of. The first, namely, that it is (and that it is impossible for it not to be), is the way of belief, for truth is its companion. The other way of inquiry, namely, that it is not (and cannot be), is a path that none can learn at all. For you cannot know what is not, nor can you express it. It is the same thing that can be thought and that can be. What can be spoken and thought must be; for it is possible for it to be, but impossible for nothing to be. . . . One path only is left for us to speak of, namely, that it is. In this path are very many signs that “what is” is uncreated and indestructible; it is complete, immovable, and without end. …

The One

[The One] is not divisible, since it is all alike, and there is no more of it in one place than in another, to hinder it from holding together, nor less of it, but everything is full of what is. For this reason it is wholly continuous; for what is, is in contact with what is.

Moreover, it is immovable in the bonds of mighty chains, without beginning and without end; since coming into being and passing away have been driven afar, and true belief has cast them away. It is the same, and it rests in the self-same place, abiding in itself. And thus it remains constant in its place; for hard necessity keeps it in the bonds of the limit that holds it fast on every side. For this reason it is not permitted to what is to be infinite; for it is in need of nothing; while, if it were infinite, it would stand in need of everything.

ZENO (fl. c. 450 BCE)

Ancient Greek philosopher from Elea who defended Parmenides’ notion of the eternal unchanging One by presenting paradoxes designed to show the impossibility of motion or any other change.

The Paradoxes

The motive of my book was to protect Parmenides against ridicule by showing that the hypothesis of the existence of the many involved greater absurdities than the hypothesis of the one. The book was a youthful composition of mine, which was stolen from me, and therefore I had no choice about the publication. [Plato, Parmenides]

Paradoxes of Motion

Zeno’s arguments about motion, which cause so much annoyance to those who try to solve the problems that they present, are four in number.

The first asserts the non-existence of motion on the ground that that which is in motion must arrive at the half-way stage before it arrives at the goal. This we have discussed above. [i.e., “It is always necessary to traverse half the distance, but these are infinite, and it is impossible to get through things that are infinite.”

The second is the so-called ‘Achilles’, and it amounts to this, that in a race the quickest runner can never overtake the slowest, since the pursuer must first reach the point whence the pursued started, so that the slower must always hold a lead. …

The third is that already given above, to the effect that the flying arrow is at rest [i.e., “If everything when it occupies an equal space is at rest, and if that which is in locomotion is always occupying such a space at any moment, the flying arrow is therefore motionless.”]

The fourth argument is that concerning the two rows of bodies, each row being composed of an equal number of bodies of equal size, passing each other on a race-course as they proceed with equal velocity in opposite directions, the one row originally occupying the space between the goal and the middle point of the course and the other that between the middle point and the starting-post. This, he thinks, involves the conclusion that half a given time is equal to double that time. [Aristotle, Physics, 6]

Paradox of Place

If place is something that exists, where will it be? The difficulty raised by Zeno requires some answer. For if everything that exists has a place, it is clear that place too will have a place, and so on without limit.

Paradox of Sound

“Tell me, Protagoras,” [Zeno said] “does a single millet seed, or the ten thousandth part of a seed, make a noise when they fall?” When Protagoras said they did not, he said: “Does the bushel then make a noise when it falls or not?” When Protagoras said this did, Zeno said: “Is there not then some ratio of the bushel to one seed, and to a ten-thousandth of a seed?” When Protagoras said there was, Zeno said: “But then must not the respective noises stand to one another in the same ratios? For as the sounding bodies are to one another, so must be the sounds they make. This being so, if the bushel of millet makes a noise, then the single millet seed must also make a noise, and so must the ten thousandth of a millet seed. [Simplicius, Physics, 1008]

EMPEDOCLES (c. 495–c. 435 BCE)

Ancient Greek philosopher who emphasized that the two forces of love and strife organize the four elements or roots of the world–namely earth, air, fire and water.

Four elements

I will tell you of a twofold process. At one time it [i.e., the cosmos] grew together to be one only out of many, at another it parted to pieces so as to be many instead of one. Fire and Water and Earth and the mighty height of Air. And also, apart from these, dreaded Strife of equal weight to each, and Love in their midst, equal in length and breadth. . . . All these elements are equal and of the same age in their creation. But each presides over its own area, and each has its own character, and they dominate in turn in the course of time.

Two forces

When Strife had fallen to the lowest depth of the vortex, and Love had reached to the center of the whirl, all things came together in it so as to be one only. This did not happen all at once, but they came together at their will each from different quarters. As they mingled, strife began to pass out to the furthest limit. Yet many things remained unmixed, alternating with the things that were being mixed, namely, all that Strife not fallen yet retained; for it had not yet altogether retired perfectly from them to the outermost boundaries of the circle. Some of it still remained within, and some had passed out from the limbs of the All. But in proportion as it kept rushing out, a soft, immortal stream of blameless Love kept running in, and immediately those things became mortal which had been immortal before, those things were mixed that had before been unmixed, each changing its path. As they mingled, countless tribes of mortal creatures were scattered abroad endowed with all manner of forms, a wonder to observe.

Many creatures with faces and breasts looking in different directions were born. Some offspring of oxen had faces of people, while others, again, arose as offspring of people with the heads of oxen. There were creatures in whom the nature of women and men was mingled, furnished with sterile parts.


Ancient Greek philosopher who held that the world is comprised of infinitely divisible elements or seeds that is organized by Mind (nous).

The Seeds

Nor is there a least of what is small, but there is always a smaller; for it cannot be that what is should cease to be by being cut. But there is also always something, greater than what is great, and it is equal to the small in amount, and, compared with itself, each thing is both great and small.

And since the portions of the great and of the small are equal in amount, for this reason, too, all things will be in everything. Nor is it possible for them to be apart, but all things have a portion of everything. Since it is impossible for there to be a least thing, they cannot be separated, nor come to be by themselves; but they must be now, just as they were in the beginning, all together. And in all things many things are contained, and an equal number both in the greater and in the smaller of the things that are separated off.


All other things partake in a portion of everything, while Mind is infinite and self-ruled, and is mixed with nothing, but is alone, itself by itself. If it were not by itself, but were mixed with anything else, it would partake in all things if it were mixed with any. For in everything there is a portion of everything, as I said earlier, and the things mixed with it would hinder it, so that it would have power over nothing in the same way that it has now being alone by itself. It is the thinnest of all things and the purest, and it has all knowledge about everything and the greatest strength. Mind has power over all things, both greater and smaller, that have life. Mind had power over the whole revolution, so that it began to revolve in the beginning. It began to revolve first from a small beginning; but the revolution now extends over a larger space, and will extend over a larger still. All the things that are mingled together and separated off and distinguished are all known by Mind.



Developed the Atomistic theory that the world is composed of indivisible particles within empty space.

Atoms in the Void

Substances are unlimited in multitude and atomic … and scattered in the void. When they approach one another or collide or become entangled, the compounds appear as water or fire or as a plant or a human. But all things are atoms, which he calls forms; there is nothing else. [Plutarch, Against Colotes]


[Leucippus and Democritus] attributed sight to certain image-flakes, of the same shape as the object, which were continually streaming off from the objects of sight and impinging on the eye. [Alexander, de sensu, 56]

The Gods

Democritus says that certain image-flakes of atoms approach humans, and of them some cause good and others evil… These are large and immense, and difficult to destroy though not indestructible. They indicate the future in advance to people when they are seen to emit voices. As a result people of ancient times, upon perceiving the appearances of these things, supposed that they are a god, though there is no other god aside from these having an indestructible nature. [Sextus Empiricus, Against the Mathematicians. 9:19]

PROTAGORAS (c. 490–c. 420 BCE)

Most famous Greek Sophist who is remembered for the statement that “man is the measure of all things.”

Relativism and Skepticism

Protagoras made the weaker and stronger arguments, and taught his students to blame and praise the same person. [Stephanus of Byzantium]

A human being is the measure of all things – of things that are, that they are, and of things that are not, that they are not.

Concerning the gods, I am unable to know either that they are or that they are not, or what their appearance is like. For many are the things that hinder knowledge: the obscurity of the matter and the shortness of human life.

GORGIAS (c. 475-375 BCE)

Greek Sophist from Leontini (Sicily), famous for his skeptical positions on ethics and knowledge.

Argument Against Existence

. . . If what-is is eternal, it is unlimited, but if it is unlimited it is nowhere, and if it is nowhere it is not. So if what-is is eternal, it is not at all. Further, what-is cannot be generated either. For if it has come to be it did so either from a thing that is or from a thing that is not. But it has come to be neither from what-is (for if it is a thing that is, it has not come to be, but already is), nor from what-is-not (for what-is-not cannot generate anything, since what generates anything must of necessity share in existence). … It follows that nothing is. For if neither what-is is nor what-is-not nor both, and nothing aside from these is conceived of, nothing is.

. . . Things seen are the objects of sight, and things heard are the objects of hearing. We accept as real things seen without their being herd, and vice versa. So we would have to accept things thought without their being seen or herd: but this would mean believing in things like the chariot racing on the sea. Therefore reality is not the object of thought, and cannot be comprehended by it.

. . . Since the objects of sight cannot give their information to one another, similarly speech cannot give any information about perceptible things. Therefore if anything exists and is comprehended, it is incommunicable. [Sextus Empiricus, Against the Mathematicians, 7.65 ff.]

SOCRATES (469–399 BCE)

Ancient Greek moral philosopher and teacher of Plato, famous for his professions of ignorance, his irony, his moral earnestness and his dialectical method of questioning people.

Socrates the Wisest Man

Chaerephon, as you know, was very impulsive in all his actions, and he went to Delphi and boldly asked the oracle to tell him whether . . . anyone was wiser than I was. Pythian prophetess answered that there was no man wiser. . . . When I heard the answer, I said to myself, What can the god mean, and what is the interpretation of his riddle? . . . After long consideration, I thought of a method of testing the question. I reflected that if I could only find a man wiser than myself, then I might go to the god with a refutation in my hand. I should say to him, “Here is a man who is wiser than I am; but you said that I was the wisest.”

Accordingly I went to one who had the reputation of wisdom, and observed him. His name I need not mention; he was a politician whom I selected for examination. The result was as follows: When I began to talk with him, I could not help thinking that he was not really wise, although he was thought wise by many, and still wiser by himself; and thereupon I tried to explain to him that he thought himself wise, but was not really wise. The consequence was that he hated me, and his hostility was shared by several who were present and heard me. . . .

After the politicians, I went to the poets . . . . I took them some of the most elaborate passages in their own writings and asked what was the meaning of them, thinking that they would teach me something. Will you believe me? I am almost ashamed to confess the truth, but I must say that there is hardly a person present who would not have talked better about their poetry than they did themselves. Then I knew that not by wisdom do poets write poetry, but by a sort of genius and inspiration; they are like diviners or soothsayers who also say many fine things, but do not understand the meaning of them. The poets appeared to me to be much in the same case. I further observed that upon the strength of their poetry they believed themselves to be the wisest of men in other things in which they were not wise. So I left, conceiving myself to be superior to them for the same reason that I was superior to the politicians.

At last I went to the artisans. I was conscious that I knew nothing at all, as I may say, and I was sure that they knew many fine things. Here I was not mistaken, since they did know many things of which I was ignorant. In this they certainly were wiser than I was. But I observed that even the good artisans fell into the same error as the poets: because they were good workmen they thought that they also knew all sorts of high matters, and this defect in them overshadowed their wisdom. . . .

Therefore I asked myself on behalf of the oracle, whether I would like to be as I was, neither having their knowledge nor their ignorance, or like them in both. I answered to myself and to the oracle that I was better off as I was. This inquisition has led to my having many enemies of the worst and most dangerous kind, and has given occasion also to many insults. I am called wise, for my hearers always imagine that I myself possess the wisdom which I find wanting in others. But the truth is, O men of Athens, that God only is wise; and by his answer he intends to show that the wisdom of men is worth little or nothing; he is not speaking of Socrates, he is only using my name by way of illustration, as if he said, He, O men, is the wisest, who, like Socrates, knows that his wisdom is in truth worth nothing. [Plato, Apology]


Socrates: Come here, Meletus, and let me ask a question of you. You think a great deal about the improvement of youth?

Meletus: Yes, I do.

Socrates: Tell the judges, then, who is their improver; for you must know, since you have taken the pains to discover their corrupter, and are citing and accusing me before them. Speak, then, and tell the judges who their improver is. Observe, Meletus, that you are silent, and have nothing to say. Isn’t this rather disgraceful, and a very considerable proof of what I was saying, that you have no interest in the matter? Speak up, friend, and tell us who their improver is.

Meletus: The laws.

Socrates: But that, my good sir, is not my meaning. I want to know who the person is, who, in the first place, knows the laws.

Meletus: The judges, Socrates, who are present in court.

Socrates: Do you mean to say, Meletus, that they are able to instruct and improve youth?

Meletus: Certainly they are.

Socrates: All of them, or some only and not others?

Meletus: All of them.

Socrates: By the goddess Hera, that is good news! There are plenty of improvers, then. And what do you say of the audience: do they improve them?

Meletus: Yes, they do.

Socrates: And the senators?

Meletus: Yes, the senators improve them.

Socrates: But perhaps the members of the assembly corrupt them, or do they too improve them?

Meletus: They improve them.

Socrates: Then every Athenian improves and elevates them, all with the exception of myself, and I alone am their corrupter. Is that what you affirm?

Meletus: That is what I stoutly affirm.

Socrates: I am very unfortunate if you are right. But suppose I ask you a question: How about horses? Does one person do them harm and all the world good? Is not the exact opposite the truth? One person is able to do them good, or at least not many; that is to say, the trainer of horses does them good, and others who have to do with them injure them instead. Isn’t that true, Meletus, of horses, or of any other animals? Certainly it is, whether you and Anytus say yes or no. The condition of the youth would be very fortunate if they had one corrupter only, and all the rest of the world were their improvers. But you, Meletus, have sufficiently shown that you never had a thought about the young: your carelessness is seen in your not caring about the very things which you bring against me. [Plato Apology]

Examining One’s Life

And so Meletus proposes death as the penalty. And what shall I propose on my part, men of Athens? Clearly that which is my due. And what is my due? What return shall be made to the man who has never had the thought to be idle during his whole life; but has been careless of what the many care for– wealth, and family interests, and military offices, and speaking in the assembly, and magistracies, and plots, and parties. Reflecting that I was really too honest a man to be a politician and live, I did not go where I could do no good to you or to myself. Instead, I went where I could do the greatest good privately to every one of you, and sought to persuade everyone among you that you must look to yourself, and seek virtue and wisdom before you look to your private interests, and look to the state before you look to the interests of the state. This should be the order which you observe in all of your actions. What shall be done to such a one? Doubtless some good thing, men of Athens, if he has his reward, and the good should be of a kind suitable to him. What would be a reward suitable to a poor man who is your benefactor, and who desires leisure that he may instruct you? There can be no reward so fitting as maintenance in the Prytaneum, men of Athens. He deserves such a reward far more than the citizen who has won the prize at Olympia in the horse or chariot race, whether the chariots were drawn by two horses or by many. For I am in want, and he has enough; he only gives you the appearance of happiness, while I give you the reality. If I am to estimate the penalty fairly, I should say that maintenance in the Prytaneum is the just reward.

Some one will say, “Yes, Socrates, but can’t you hold your tongue, and then you may go into a foreign city, and no one will interfere with you?” Now I have great difficulty in making you understand my answer to this. You will not believe that I am serious if I tell you that to do as you say would be a disobedience to the god, and therefore that I cannot hold my tongue. You are still less likely to believe me if I say again that the greatest human good is daily discussion about virtue (and of those other things about which you hear me examining myself and others), and that the unexamined life is not worth living. [Plato, Apology]

Old Age

If my age is still to be prolonged, I know that I cannot escape paying the penalty of old age, in increasing dimness of sight and dullness of hearing. I shall find myself slower to learn new lessons, and more apt to forget the lessons I have learnt. And if to these be added the consciousness of failing powers, the sting of self-reproach, what prospect have I of any further joy in living? It may be, you know, that God out of his great kindness is intervening in my behalf to suffer me to close my life in the ripeness of age, and by the gentlest of deaths. For if at this time sentence of death be passed upon me, it is plain I shall be allowed to meet an end which, in the opinion of those who have studied the matter, is not only the easiest in itself, but one which will cause the least trouble to one’s friends, while engendering the deepest longing for the departed. For of necessity he will only be thought of with regret and longing who leaves nothing behind unseemly or uncomfortable to haunt the imagination of those beside him, but, sound of body, and his soul still capable of friendly repose, fades tranquilly away. [Xenophon, Apology]

Obedience to the State

Consider, Socrates, if this is true, that in your present attempt you are going to do us wrong. For, after having brought you into the world, and nurtured and educated you, and given you and every other citizen a share in every good that we had to give, we further proclaim and give the right to every Athenian, that if he does not like us when he has come of age and has seen the ways of the city, and made our acquaintance, he may go where he pleases and take his goods with him; and none of us laws will forbid him or interfere with him. Any of you who does not like us and the city, and who wants to go to a colony or to any other city, may go where he likes, and take his goods with him. But he who has experience of the manner in which we order justice and administer the State, and still remains, has entered into an implied contract that he will do as we command him. And he who disobeys us is, as we maintain, wrong in three ways. First, because in disobeying us he is disobeying his parents; secondly, because we are the authors of his education; thirdly, because he has made an agreement with us that he will duly obey our commands. . . . Moreover, you might, if you had liked, have fixed the penalty at banishment in the course of the trial-the State which refuses to let you go now would have let you go then. But you pretended that you preferred death to exile, and that you were not grieved at death. And now you have forgotten these fine sentiments, and pay no respect to us, the laws, of whom you are the destroyer; and are doing what only a miserable slave would do, running away and turning your back upon the compacts and agreements which you made as a citizen. [Plato, Crito]

Socrates’ Death

Crito made a sign to the servant, who was standing by; and he went out, and having been absent for some time, returned with the jailer carrying the cup of poison. Socrates said: “You, my good friend, who are experienced in these matters, shall give me directions how I am to proceed.” The man answered: “You have only to walk about until your legs are heavy, and then to lie down, and the poison will act.” At the same time he handed the cup to Socrates . . . then raising the cup to his lips, quite readily and cheerfully he drank off the poison. Up till then most of us had been able to control our sorrow; but now when we saw him drinking, and saw too that he had finished, we could no longer forbear, and in spite of myself my own tears were flowing fast. I covered my face and wept, not for him, but at the thought of my own calamity in having to part from such a friend. Nor was I the first. For Crito, when he found himself unable to restrain his tears, had got up, and I followed. At that moment, Apollodorus, who had been weeping all the time, broke out in a loud and passionate cry which made cowards of us all. Socrates alone retained his calmness. “What is this strange outcry?” he said. “I sent away the women mainly in order that they might not misbehave in this way, for I have been told that a man should die in peace. Be quiet, then, and have patience.” When we heard his words we were ashamed, and refrained our tears. He walked about until, as he said, his legs began to fail, and then he lay on his back, according to the directions. The man who gave him the poison now and then looked at his feet and legs; after a while he pressed his foot hard, and asked him if he could feel; he said “No.” Then his leg, and so upwards and upwards, and showed us that he was cold and stiff. He felt them himself and said, “When the poison reaches the heart, that will be the end.” He was beginning to grow cold about the groin, when he uncovered his face, for he had covered himself up, and said–they were his last words–he said: “Crito, I owe a chicken to Asclepius; will you remember to pay the debt?” Crito said, “The debt shall be paid; is there anything else?” There was no answer to this question; but in a minute or two a movement was heard, and the attendants uncovered him. His eyes were set, and Crito closed his eyes and mouth. Such was the end of our friend, concerning whom I may truly say, that of all the men of his time whom I have known, he was the wisest and justest and best. [Plato, Phaedo]

PLATO (428–348 BCE)

Ancient Greek philosopher who argued for the theory of the forms, the immortality of the soul, and the grounding of justice in eternal unchanging forms.

Knowledge vs. Opinion

We seem to have discovered that the many ideas which the multitude entertain about the beautiful and about all other things are tossing about in some region which is halfway between pure being and pure not-being. . . . We had before agreed that anything of this kind which we might find is to be described as a matter of opinion, and not as a matter of knowledge, since it is the intermediate flux which is caught and detained by the intermediate faculty. . . . Then those who see the many beautiful, and who yet neither see absolute beauty, nor can follow any guide who points the way there; who see the many just, and not absolute justice, and the like – such persons may be said to have opinion but not knowledge? . . . But those who see the absolute and eternal and immutable may be said to know, and not to have opinion only? [Republic, Bk. 5]

The Divided Line

[Socrates:] Now take a line which has been cut into two unequal parts, and divide each of them again in the same proportion, and suppose the two main divisions to answer, one to the visible and the other to the intelligible, and then compare the subdivisions in respect of their clearness and want of clearness, and you will find that the first section in the sphere of the visible consists of images. And by images I mean, in the first place, shadows, and in the second place, reflections in water and in solid, smooth and polished bodies and the like: Do you understand?

[Glaucon:] Yes, I understand.

[Socrates:] You have to imagine, then, that there are two ruling powers, and that one of them is set over the intellectual world, the other over the visible. I do not say heaven, lest you should fancy that I am making a play on words. May I suppose that you have this distinction of the visible and intelligible fixed in your mind?

[Glaucon:] I have.

[Socrates:] Imagine, now, the other section (B), of which this is only the resemblance, to include the animals which we see, and everything that grows or is made.

[Glaucon:] Very good.

[Socrates:] Would you not admit that both the sections of this division have different degrees of truth, and that the copy is to the original as the sphere of opinion is to the sphere of knowledge?

[Glaucon:] Most undoubtedly.

[Socrates:] Next proceed to consider the manner in which the sphere of the intellectual is to be divided.

[Glaucon:] In what manner?

[Socrates:] Thus, there are two subdivisions. In the lower of the two (C), the soul uses the figures given by the former division as images; the inquiry can only be hypothetical, and instead of going upwards to a principle descends to the other end. In the higher of the two (D), the soul passes out of hypotheses, and goes up to a principle which is above hypotheses, making no use of images as in the former case, but proceeding only in and through the ideas themselves.

[Glaucon:] I do not quite understand your meaning, he said.

[Socrates:] Then I will try again. (C) You will understand me better when I have made some preliminary remarks. You are aware that students of geometry, arithmetic, and the kindred sciences assume the odd and the even and the figures and three kinds of angles and the like in their several branches of science; these are their hypotheses, which they and everybody are supposed to know, and therefore they do not deign to give any account of them either to themselves or others; but they begin with them, and go on until they arrive at last, and in a consistent manner, at their conclusion?

[Glaucon:] Yes, he said, I know.

[Socrates:] And do you not know also that although they make use of the visible forms and reason about them, they are thinking not of these, but of the ideals which they resemble; not of the figures which they draw, but of the absolute square and the absolute diameter, and so on—the forms which they draw or make, and which have shadows and reflections in water of their own, are converted by them into images, but they are really seeking to behold the things themselves, which can only be seen with the eye of the mind?

[Glaucon:] That is true.

[Socrates:] And of this kind I spoke as the intelligible, although in the search after it the soul is compelled to use hypotheses; not ascending to a first principle, because she is unable to rise above the region of hypothesis, but employing the objects of which the shadows below are resemblances in their turn as images, they having in relation to the shadows and reflections of them a greater distinctness, and therefore a higher value.

[Glaucon:] I understand, he said, that you are speaking of the province of geometry and the sister arts.

[Socrates:] And when I speak of the other division (D) of the intelligible, you will understand me to speak of that other sort of knowledge which reason herself attains by the power of dialectic, using the hypotheses not as first principles, but only as hypotheses—that is to say, as steps and points of departure into a world which is above hypotheses, in order that she may soar beyond them to the first principle of the whole; and clinging to this and then to that which depends on this, by successive steps she descends again without the aid of any sensible object, from ideas, through ideas, and in ideas she ends.

[Glaucon:] I understand you, he replied; not perfectly, for you seem to me to be describing a task which is really tremendous; but, at any rate, I understand you to say that knowledge and being, which the science of dialectic contemplates, are clearer than the notions of the arts, as they are termed, which proceed from hypotheses only: these are also contemplated by the understanding, and not by the senses: yet, because they start from hypotheses and do not ascend to a principle, those who contemplate them appear to you not to exercise the higher reason upon them, although when a first principle is added to them they are cognizable by the higher reason. And the habit which is concerned with geometry and the cognate sciences I suppose that you would term understanding and not reason, as being intermediate between opinion and reason.

[Socrates:] You have quite conceived my meaning, I said; and now, corresponding to these four divisions, let there be four faculties in the soul—reason answering to the highest, understanding to the second, faith (or conviction) to the third, and perception of shadows to the last—and let there be a scale of them, and let us suppose that the several faculties have clearness in the same degree that their objects have truth.

[Glaucon:] I understand, he replied, and give my assent, and accept your arrangement. [Republic, 6]

The Allegory of the Cave

Consider a situation in which human beings live in an underground den, which has a mouth open towards the light and reaching all along the den. Here they have lived since their childhood, and have their legs and necks chained so that they cannot move, and can only see before them, being prevented by the chains from turning round their heads. Above and behind them a fire is blazing at a distance, and between the fire and the prisoners there is a raised way; and you will see, if you look, a low wall built along the way, like the screen which marionette players have in front of them, over which they show the puppets. . . . They see only their own shadows, or the shadows of one another, which the fire throws on the opposite wall of the cave. . . .

Imagine what will naturally happen if the prisoners are released and freed of their error. At first, when any of them is liberated and compelled suddenly to stand up and turn his neck round and walk and look towards the light, he will suffer sharp pains. The glare will distress him, and he will be unable to see the realities of which in his former state he had seen the shadows. Imagine further someone saying to him that what he saw before was an illusion, but that now, when he is approaching nearer to being and his eye is turned towards more real existence, he has a clearer vision. What will be his reply? Imagine still further that his instructor is pointing to the objects as they pass and requires him to name them. Won’t he be perplexed? Won’t he think that the shadows which he formerly saw are truer than the objects which are now shown to him? . . . Suppose once more, that he is reluctantly dragged up a steep and rugged ascent, and held fast until he’s forced into the presence of the sun itself, is he not likely to be pained and irritated? When he approaches the light his eyes will be dazzled, and he will not be able to see anything at all of what are now called realities.

He will need to grow accustomed to the sight of the upper world. And first he will see the shadows best, next the reflections of men and other objects in the water, and then the objects themselves. Then he will gaze upon the light of the moon and the stars and the glittery heaven; he will see the sky and the stars by night better than the sun or the light of the sun by day. Last of all, he will be able to see the sun, and not mere reflections of it in the water, but he will see it in his own proper place . . .

When he remembers his old habitation, and the wisdom of the den and his fellow-prisoners, do you not suppose that he would congratulate himself on the change, and pity them? . . . . If there were a contest, and he had to compete in measuring the shadows with the prisoners who had never moved out of the den, while his sight was still weak, and before his eyes had become steady (and the time which would be needed to acquire this new habit of sight might be very considerable) would he not be ridiculous? Men would say of him that up he went and down he came without his eyes; and that it was better not even to think of ascending. If any one tried to loose another and lead him up to the light, let them only catch the offender, and they would put him to death. . . .

The prison-house is the world of sight, the light of the fire is the sun, and you will not misunderstand me if you interpret the journey upwards to be the ascent of the soul into the intellectual world according to my poor belief, which, at your desire, I have expressed whether rightly or wrongly God knows. But, whether true or false, my opinion is that in the world of knowledge the idea of good appears last of all, and is seen only with an effort; and, when seen, is also inferred to be the universal author of all things beautiful and right, parent of light and of the lord of light in this visible world, and the immediate source of reason and truth in the intellectual; and that this is the power upon which he who would act rationally, either in public or private life must have his eye fixed. . . .

Moreover, I said, you must not wonder that those who attain to this beatific vision are unwilling to descend to human affairs; for their souls are ever hastening into the upper world where they desire to dwell; which desire of theirs is very natural, if our allegory may be trusted. . . . Is there anything surprising in one who passes from divine contemplations to the evil state of man, misbehaving himself in a ridiculous manner; if, while his eyes are blinking and before he has become accustomed to the surrounding darkness, he is compelled to fight in courts of law, or in other places, about the images or the shadows of images of justice, and is endeavoring to meet the conceptions of those who have never yet seen absolute justice? [Republic, 7]

Knowledge as Recollection

The soul, as being immortal, and having been born again many times, and having seen all things that exist, whether in this world or in the world below, has knowledge of them all. It is no wonder that it should be able to call to remembrance all that it ever knew about virtue, and about everything. For, all nature is similar, and the soul has learned all things. Thus, there is no difficulty in the soul drawing out and learning all things from a single recollection, so long as a person is strenuous and does not faint. All inquiry and all learning is simply recollection. Therefore, we ought not to listen to this sophistical argument about the impossibility of inquiry, since it will make us idle and will appeal only to the lazy person. But the other saying will make us active and inquisitive. [Meno, 81 c-d]

Body-Soul Dualism

When real philosophers consider all these things, will they not be led to make a reflection which they will express in words something like the following? Have we not found, they will say, a path of thought which seems to bring us and our argument to the conclusion, that while we are in the body, and while the soul is infected with the evils of the body, our desire will not be satisfied? And our desire is of the truth. For the body is a source of endless trouble to us because of the mere requirement of food. It is liable also to diseases which overtake and hinder us in the search after true being. It fills us full of loves, and lusts, and fears, and fancies of all kinds, and endless foolishness, and in fact, as people say, it takes away from us the power of thinking at all. What is the source of come wars, and fighting, and factions? The body and the lusts of the body. Wars are occasioned by the love of money, and money has to be acquired for the sake and in the service of the body. Because of all these obstacles, we have no time to give to philosophy. Last and worst of all, even if we have free time and commit ourselves to some speculation, the body is always breaking in upon us, causing turmoil and confusion in our inquiries, and so distracting us that we are prevented from seeing the truth. Experience shows that if we would have pure knowledge of anything, we must leave the body. The soul by herself must observe things in themselves. Then we shall attain the wisdom which we desire, and of which we say that we are lovers, not while we live, but after death. If while in company with the body, the soul cannot have pure knowledge, one of two things follows: either knowledge cannot be attained at all, or, if at all, only after death. For then, and not till then, the soul will be parted from the body and exist in herself alone. In this present life we make the nearest approach to knowledge when we have the least possible contact or association with the body, and are not overindulged with the bodily nature, but instead keep ourselves pure until the hour when God himself is pleased to release us. And thus having got rid of the foolishness of the body we shall be pure and commune with the pure, and know of ourselves the clear light everywhere, which is no other than the light of truth. For the impure are not permitted to approach the pure. [Phaedo]

Immortality of the Soul: Argument from the Unchangeable Forms

Socrates: Is the soul more like the unseen, and the body like the seen?

Cebes: That is most certain, Socrates.

Socrates: Remember what we said before about when the soul uses the body as an instrument of perception, that is, when it uses the sense of sight or hearing or some other sense (for the meaning of perceiving through the body is perceiving through the senses). Were we not saying that the soul too is then dragged by the body into the region of the changeable, and wanders and is confused; the world spins round her, and she is like a drunkard when under their influence?

Cebes: Very true.

Socrates: But when returning into herself she reflects. Then she passes into the realm of purity, and eternity, and immortality, and unchangeableness, which are her kindred, and with them she ever lives, when she is by herself and is not let or hindered; then she ceases from her erring ways, and being in association with the unchanging is unchanging. Isn’t this state of the soul is called wisdom?

Cebes: That is well and truly said, Socrates, he replied.

Socrates: And to which class is the soul more nearly alike and related, as far as may be inferred from this argument, as well as from the preceding one?

Cebes: I think, Socrates, that, in the opinion of everyone who follows the argument, the soul will be infinitely more like the unchangeable. Even the most stupid person will not deny that.

Socrates: And the body is more like the changing?

Cebes: Yes.

Socrates: Yet once more consider the matter in this light. When the soul and the body are united, then nature orders the soul to rule and govern, and the body to obey and serve. Now consider which of these two functions is more like the divine, and which is more like the mortal. Doesn’t the divine appear to you to be that which naturally orders and rules, and the mortal that which is subject and servant?

Cebes: True.

Socrates: And which does the soul resemble?

Cebes: The soul resembles the divine and the body the mortal; there can be no doubt of that, Socrates.

Socrates: Then reflect, Cebes, whether the conclusion of the whole matter is this. The soul is in the very likeness of the divine, and immortal, and intelligible, and uniform, and indissoluble, and unchangeable. By contrast, the body is in the very likeness of the human, and mortal, and unintelligible, and multiform, and dissoluble, and changeable. Can this, my dear Cebes, be denied?

Cebes: No, indeed.

Socrates: If this is true, then isn’t the body susceptible to speedy dissolution? and is not the soul almost or altogether indissoluble? [Phaedo]

Immortality of the Soul: Argument from Motion

The soul through all her being is immortal. For that which is ever in motion is immortal, but that which moves another and is moved by another, in ceasing to move ceases also to live. Only the self-moving, never leaving self, never ceases to move, and is the fountain and beginning of motion to all that moves besides. Now, the beginning is uncreated, for that which is created has a beginning; but the beginning is created of nothing, for if it were created by something, then the created would not come from a beginning. But if it is uncreated, it must also be indestructible; for if beginning were destroyed, there could be no beginning out of anything, nor anything out of a beginning; and all things must have a beginning. And therefore the self-moving is the beginning of motion; and this can neither be destroyed nor created, otherwise the whole heavens and all creation would collapse and stand still, and never again have motion or birth. But if the self-moving is proved to be immortal, he who affirms that self-motion is the very idea and essence of the soul will not be put to confusion. For the body which is moved from without is lacks a soul. However, that which is moved from within has a soul, for such is the nature of the soul. If this is true, must not the soul be the self-moving, and therefore of necessity uncreated and immortal? Enough of the soul’s immortality. [Phaedrus, 245d-e]:

Three Parts of the Soul

As I said at the beginning of this tale, I divided the soul into three parts: two horses and a charioteer. One of the horses was good and the other bad. Let’s continue with this division, although I have not yet explained in what the goodness or badness of either consists, and to that I will now proceed. The right-hand horse is upright and cleanly made. He has a lofty neck and an curved nose; his color is white, and his eyes dark; he is a lover of honor and modesty and temperance, and the follower of true glory; he needs no sting of the whip, but is guided by word and gentle warning only.

The other is a crooked and lumbering animal, put together every which way. He has a short thick neck; he is flat-faced and of a dark color, with grey and blood-shot eyes. He is the companion of insolence and pride, shag-eared and deaf, barely yielding to whip and spur.

Now the charioteer observes the vision of his lover, and has his whole soul warmed through sensation, and is full of the tingling and itching of desire. When this happens, the obedient horse, which is always under the rule of shame, refrains from leaping on the lover. But the other horse, ignoring of the stings and of the blows of the whip, plunges and runs away, giving all manner of trouble to his companion and the charioteer. The horse forces the charioteer to approach his lover and to remember the joys of love. . . . The charioteer sees his lover, but he is afraid and falls backwards in adoration, and by his fall is compelled to pull back the reins with such violence as to bring both the steeds on their haunches, the one willing and unresisting, the unruly one very unwilling. [Phaedrus, 253 d-e]

Justice as Doing One’s Own

Socrates: On this view we will recognize that justice is the having and doing what is a person’s own, and belongs to him?

Glaucon: Very true.

Socrates: Consider this, now, and say whether you agree with me or not. Suppose that a carpenter does the business of a cobbler, or a cobbler of a carpenter. Suppose they exchange their implements or their duties, or the same person does the work of both, or whatever be the change. Do you think that any great harm would result to the State?

Glaucon: Not much.

Socrates: Suppose that the cobbler or any other man whom nature designed to be a tradesperson, has his heart lifted up by wealth or strength or the number of his followers, or any like advantage, and attempts to force his way into the class of warriors. Suppose a warrior moves into that of legislators and guardians, for which he is unfitted, and either to take the implements or the duties of the other. Suppose that one man is a tradesperson, legislator, and warrior all in one. I think you will agree with me in saying that this interchange and this meddling of one with another is the ruin of the State. [Republic, Bk. 4]

Noble Lie

Citizens, we will say to them in our tale, you are brothers, yet God has framed you differently. Some of you have the power of command, and in the composition of these God has mingled gold, for which reason they have the greatest honor. Others God has made of silver, to be warriors. Others again who are to be farmers and tradespeople he has composed of brass and iron. Generally, the species will be preserved in their children. But since all people are of the same original stock, a golden parent will sometimes have a silver son, or a silver parent a golden son. And God proclaims as a first principle to the rulers, and above all else, that there is nothing which they should so anxiously guard, or of which they are to be such good guardians, as the purity of the race. They should observe what elements mingle in their offspring. If the son of a golden or silver parent has a mixture of brass and iron, then nature orders a transposition of ranks, and the eye of the ruler must not be sympathetic towards the child because he has to move down in the social scale and become a farmer or tradesperson. Similarly, there may be sons of tradespeople who having a mixture of gold or silver in them are raised to honor, and become guardians or warriors. For a prophecy says that when a man of brass or iron guards the State, it will be destroyed. Such is the tale. Is there any possibility of making our citizens believe in it?

Not in the present generation, he replied; there is no way of accomplishing this; but their sons may be made to believe in the tale, and their sons’ sons, and posterity after them. [Republic, Bk. 3]


Until philosophers are kings, or the kings and princes of this world have the spirit and power of philosophy, and political greatness and wisdom meet in one, and those commoner natures who pursue either to the exclusion of the other are compelled to stand aside, cities will never have rest from their evils – no, nor the human race, as I believe. Only then will our State have a possibility of life and behold the light of day. . . . We will discover some people whose natures are such that they ought to study philosophy and to be leaders in the State. There are others who are not born to be philosophers, and are meant to be followers rather than leaders. …

And may we not say of the philosopher that he is a lover, not of a part of wisdom only, but of the whole? [Republic, Bk. 5]


If the craftsman does not make that which really is, then he cannot make true existence, but only something that resembles real existence. If anyone were to say that the work of the maker of the bed, or of any other craftsman, has real existence, he could hardly be supposed to be speaking the truth. . . . No wonder, then, that his work too is an indistinct expression of truth. [Republic, 10; 597a]

Then the first thing will be to establish a censorship of the writers of fiction, and let the censors receive any tale of fiction which is good, and reject the bad; and we will desire mothers and nurses to tell their children the authorized ones only. Let them fashion the mind with such tales, even more fondly than they mould the body with their hands; but most of those which are now in use must be discarded.


Ancient Greek philosopher who emphasized the notion of a thing’s purpose (telos) and argued that morality involves the development of virtues.


Non-composite expressions signify substance, quantity, quality, relation, place, time, position, state, action, or affection. To sketch my meaning roughly, examples of substance are “man” or “the horse”, of quantity, such terms as “two cubits long” or “three cubits long”, of quality, such attributes as “white”, “grammatical”. “Double”, “half”, “greater”, fall under the category of relation; “in the market place”, “in the Lyceum”, under that of place; “yesterday”, “last year”, under that of time. “Lying”, “sitting”, are terms indicating position, “wearing shoes”, “armed”, state; “to lance”, “to cauterize”, action; “to be lanced”, “to be cauterized”, affection. [Categories, 1.4]

Fallacies of the Sophists

That some reasonings are genuine, while others seem to be so but are not, is evident. This happens with arguments, as also elsewhere, through a certain likeness between the genuine and the sham. . . .

In the case of names that are used literally, a person is bound to answer either without qualification or by drawing a distinction. Fallacy thus depends on the tacit understanding implied in our statements, such as when answering questions that are not put clearly but instead are abbreviated. Consider this illustration. “Is what belongs to Athenians the property of Athenians?” Yes. “And so it is likewise in other cases. But man belongs to the animal kingdom, doesn’t he?” Yes. “Then man is the property of the animal kingdom.” For we say that man belongs to the animal kingdom because he is an animal, just as we say that Lysander belongs to the Spartans, because he is a Spartan. It is evident, then, that where what is put forward is not clear, one must grant it without qualification. [Fallacies of the Sophists, 17]

Natural and Artificial Objects

Of things that exist, some exist by nature, and some from other causes. ‘By nature’ the animals and their parts exist, and also the plants and the simple bodies (earth, fire, air, water). For, we say that these and the like exist “by nature”. All the things mentioned present a feature in which they differ from things which are not constituted by nature. Each of them has within itself a principle of motion and of stability (in respect of place, or of growth and decrease, or by way of alteration). On the other hand, [artificial objects, such as] a bed and a coat and anything else of that sort, as receiving these designations (that is, in so far as they are products of art) have no innate impulse to change. But in so far as they happen to be composed of stone or of earth or of a mixture of the two, they do have such an impulse. And they have that impulse to that extent which seems to indicate that nature is a source or cause of being moved and of being at rest in that to which it belongs primarily, in virtue of itself and not in virtue of a connected attribute. [Physics, 1.4]

Four Causes

We must proceed to consider causes, their character and number. Knowledge is the object of our inquiry, and men do not think they know a thing till they have grasped the ‘why’ of (which is to grasp its primary cause). So clearly we too must do this as regards both coming to be and passing away and every kind of physical change, in order that, knowing their principles, we may try to refer each of our problems to these principles.

In one sense, then, (1) that out of which a thing comes to be and which persists, is called ‘cause’. This is so, for example, regarding the bronze of the statue, the silver of the bowl, and the genera of which the bronze and the silver are species.

In another sense (2) the form or the pattern (the definition of the essence), and its genera, are called ‘causes’. This is so, for example, regarding the octave the relation of 2:1, and numbers generally, and the parts in the definition.

Again, (3) [a causes is] the primary source of the change or coming to rest. For example, the man who gave advice is a cause, the father is cause of the child, and generally what makes of what is made and what causes change of what is changed.

Again, (4) [something is a cause] in the sense of end or “that for the sake of which” a thing is done. For example, health is the cause of walking about. If asked “Why is he walking about?” we say, “To be healthy”. Having said that, we think we have assigned the cause. The same is true also of all the intermediate steps which are brought about through the action of something else as means towards the end. For example, reduction of flesh, purging, drugs, or surgical instruments are means towards health. All these things are “for the sake of” the end, though they differ from one another in that some are activities, others instruments.

This then perhaps exhausts the number of ways in which the term ‘cause’ is used. [Physics 2.3]

Substance and Accident

We call “substance” (1) the simple bodies, that is, earth and fire and water and everything of the sort, and in general bodies and the things composed of them, both animals and divine beings, and the parts of these. All these are called substance because they are not predicated of a subject but everything else is predicated of them. [We also call “substance”] (2) that which, being present in such things as are not predicated of a subject, is the cause of their being, as the soul is of the being of an animal. . . .

“Accident” means (1) that which attaches to something and can be truly asserted, but neither of necessity nor usually. For example, if some one in digging a hole for a plant has found treasure. This (the finding of treasure) is an accident for the man who dug the hole, since neither does the one come of necessity from the other (or after the other), nor does he usually find treasure if he digs to plant something. A musician might be pale; but since this does not happen of necessity nor usually, we call it an accident. There are, then, attributes and they attach to subjects, and some of them attach to these only in a particular place and at a particular time. Thus, something will be an accident whenever it attaches to a subject, but not because it was this subject, or the time this time, or the place this place. Therefore, too, there is no definite cause for an accident, but a chance cause, that is, an indefinite one. Going to Aegina was an accident for a man, if he went not in order to get there, but because he was carried out of his way by a storm or captured by pirates. The accident has happened or exists, not in virtue of the subject’s nature, however, but of something else. For, the storm was the cause of his coming to a place for which he was not sailing, and this was Aegina. [Metaphysics, 5.8, 5.30]

Potentiality and Actuality

[W]ith regard to the potential, that we not only ascribe potentiality to that whose nature it is to move something else, or to be moved by something else, either without qualification or in some particular way, but also use the word in another sense, which is the reason of the inquiry in the course of which we have discussed these previous senses also. Actuality, then, is the existence of a thing not in the way which we express by “potentially”. we say that potentially, for instance, a statue of Hermes is in the block of wood and the half-line is in the whole, because it might be separated out, and we call even the man who is not studying a man of science, if he is capable of studying; the thing that stands in contrast to each of these exists actually. Our meaning can be seen in the particular cases by induction, and we must not seek a definition of everything but be content to grasp the analogy, that it is as that which is building is to that which is capable of building, and the waking to the sleeping, and that which is seeing to that which has its eyes shut but has sight, and that which has been shaped out of the matter to the matter, and that which has been wrought up to the unwrought. Let actuality be defined by one member of this antithesis, and the potential by the other. But all things are not said in the same sense to exist actually, but only by analogy-as A is in B or to B, C is in D or to D; for some are as movement to potentiality, and the others as substance to some sort of matter. [Metaphysics, 9.6]

Unmoved Mover

The first heaven [i.e., the outer sphere of the universe] must be eternal. There is therefore also something which moves it. And since that which moves and is moved is intermediate, there is something which moves without being moved, being eternal, substance, and actuality. And the object of desire and the object of thought move in this way; they move without being moved. … The final cause, then, produces motion as being loved, but all other things move by being moved. … On such a principle, then, depend the heavens and the world of nature. …

It is clear then from what has been said that there is a substance which is eternal and unmovable and separate from sensible things. It has been shown also that this substance cannot have any magnitude, but is without parts and indivisible (for it produces movement through infinite time, but nothing finite has infinite power; and, while every magnitude is either infinite or finite, it cannot, for the above reason, have finite magnitude, and it cannot have infinite magnitude because there is no infinite magnitude at all). But it has also been shown that it is impassive and unalterable; for all the other changes are posterior to change of place. . . .

Since we see that besides the simple spatial movement of the universe, which we say the first and unmovable substance produces, there are other spatial movements-those of the planets-which are eternal. Each of these movements also must be caused by a substance both unmovable in itself and eternal. . . . Evidently, then, there must be substances which are of the same number as the movements of the stars, and in their nature eternal, and in themselves unmovable, and without magnitude, for the reason before mentioned. That the movers are substances, then, and that one of these is first and another second according to the same order as the movements of the stars, is evident. … the number of all the spheres–both those which move the planets and

those which counteract these–will be fifty-five. Let this, then, be taken as the number of the spheres, so that the unmovable substances and principles also may probably be taken as just so many. [Metaphysics, 12.7-8]

Soul as Life

We are in the habit of recognizing, as one determinate kind of what is, substance, and that in several senses, (a) in the sense of matter or that which in itself is not ‘a this’, and (b) in the sense of form or essence, which is that precisely in virtue of which a thing is called ‘a this’, and thirdly (c) in the sense of that which is compounded of both (a) and (b). … Every natural body which has life in it is a substance in the sense of a composite. But since it is also a body of such and such a kind, viz. having life, the body cannot be soul; the body is the subject or matter, not what is attributed to it. Hence the soul must be a substance in the sense of the form of a natural body having life potentially within it. [On the Soul, 2.1]

Soul requires a Body

Suppose that the eye were an animal: sight would have been its soul (for sight is the substance or essence of the eye which corresponds to the formula, the eye being merely the matter of seeing). When seeing is removed, the eye is no longer an eye, except in name. It is no more a real eye than the eye of a statue or of a painted figure. . . . As the pupil plus the power of sight constitutes the eye, so the soul plus the body constitutes the animal. From this it indubitably follows that the soul is inseparable from its body… [On the Soul, 2.1]

The soul does not exist without a body and yet is not itself a kind of body. For it is not a body, but something which belongs to a body, and for this reason exists in a body, and in a body of such-and-such a kind. [On the Soul, 2.2]

Nutritive, Appetitive, and Reasoning Souls

What has soul in it differs from what lacks it, in that the former displays life. Now the word “living” has more than one sense; if any one alone of these is found in a thing we say that thing is living. “Living” may mean thinking or perception or local movement and rest, or movement in the sense of nutrition, decay and growth. Hence we think of plants also as living, for they are observed to possess in themselves an originative power through which they increase or decrease in all spatial directions; they grow up and down, and everything that grows increases its bulk alike in both directions or indeed in all, and continues to live so long as it can absorb nutriment. . . . Certain kinds of animals possess in addition the power of locomotion, and still another order of animate beings, i.e. man and possibly another order like man or superior to him, the power of thinking, i.e. mind.

Hence we must ask in the case of each order of living things, What is its soul, i.e. What is the soul of plant, animal, man? Why the terms are related in this serial way must form the subject of later examination. But the facts are that the power of perception is never found apart from the power of self-nutrition, while (in plants) the latter is found isolated from the former. Again, no sense is found apart from that of touch, while touch is found by itself; many animals have neither sight, hearing, nor smell. Again, among living things that possess sense some have the power of locomotion, some not. Lastly, a small minority of certain living beings possess calculation and thought, for (among mortal beings) those which possess calculation have all the other powers above mentioned, while the converse does not hold-indeed some live by imagination alone, while others have not even imagination. The mind that knows with immediate intuition presents a different problem. [On the Soul, 2.3]

Happiness and the Human Function

It appears that happiness is something final and self-sufficient, being the end of all action. While it seems a generally admitted truth that happiness is the supreme good, what we need is to define its nature a little more clearly. The best way of arriving at such a definition will probably be to ascertain the function of humans. For, as with a flute-player, a statuary, or any artisan, or in fact anybody who has a definite function and action, his goodness, or excellence seems to lie in his function, so it would seem to be with humans, if indeed he has a definite function. Can it be said then that, while a carpenter and a cobbler have definite functions and actions, humans, unlike them, is naturally functionless? The reasonable view is that, as the eye, the hand, the foot, and similarly each several part of the body has a definite function, so humans may be regarded as having a definite function apart from all these. What then, can this function be? It is not life; for life is apparently something which humans shares with the plants; and it is something peculiar to him that we are looking for. We must exclude therefore the life of nutrition and increase. There is next what may be called the life of sensation. But this too, is apparently shared by humans with horses, cattle, and all other animals. There remains what I may call the practical life of the rational part of human nature. But the rational part is twofold; it is rational partly in the sense of being obedient to reason, and partly in the sense of possessing reason and intelligence. The practical life too may be conceived of in two ways, either as a moral state, or as a moral activity: but we must understand by it the life of activity, as this seems to be the truer form of the conception. [Nicomachean Ethics, 1.7]

The Virtuous Mean

It is moral virtue which is concerned with emotions and actions, and it is these which admit of excess and deficiency and the mean. Thus it is possible to go too far, or not to go far enough, in respect of fear, courage, desire, anger, pity, and pleasure and pain generally, and the excess and the deficiency are alike wrong; but to experience these emotions at the right times and on the right occasions and towards the right persons and for the right causes and in the right manner is the mean or the supreme good, which is characteristic of virtue. Similarly there may be excess, deficiency, or the mean, in regard to actions. But virtue is concerned with emotions and actions, and here excess is an error and deficiency a fault, whereas the mean is successful and praiseworthy, and success and merit are both characteristics of virtue. It appears then that virtue is a mean state, so far at least as it aims at the mean. . . .

But it is not enough to lay down this as a general rule; it is necessary to apply it to particular cases, as in reasonings upon actions general statements, although they are broader, are less exact than particular statements. For all action refers to particulars, and it is essential that our theories should harmonize with the particular cases to which they apply. We must take particular virtues then from the catalogue of [twelve specific] virtues.

(1) In regard to feelings of fear and confidence courage is a mean state. On the side of excess, he whose fearlessness is excessive has no name, as often happens, but he whose confidence is excessive is rash, while he whose timidity is excessive and whose confidence is deficient is a coward.

(2) In respect of pleasures and pains (although not indeed of all pleasures and pains, and to a less extent in respect of pains than of pleasures) the mean state is temperance, the excess is overindulgence. We never find people who are deficient in regard to pleasures; accordingly such people again have not received a name, but we may call them insensible. [Nicomachean Ethics, 2.7]

Virtues are means between extremes; they are states of character; by their own nature they tend to the doing of acts by which they are produced; they are in our power and voluntary; they act as prescribed by right reason. [Nicomachean Ethics, 3.25]

The State is a Creation of Nature

It is evident that the state is a creation of nature, and that man is by nature a political animal. Whoever is unfit for society naturally (and not merely accidentally), must be either inferior or superior to man. He is like the man in Homer who is despised for being “without society, without law, without family.” Such a person must naturally be of a quarrelsome disposition, and as solitary as the birds. Now, it is evident that man is more of a political animal than bees or any other social animals. Nature, as we often say, does nothing in vain, and man is the only animal whom she has endowed with the gift of speech. It is true that voice, as being the indicator of pleasure and pain, is also found in other animals (thus much of their nature is capable of perceiving pleasure and pain, and imparting these sensations to others). But it is by speech that we are able to express what is useful for us, what is hurtful, and of course what is just and what is unjust. In this particular man differs from other animals. He alone has a perception of good and evil, of just and unjust; it is the association of living beings who have this sense that makes a family and a state.

Further, the state is by nature clearly prior to the family and to the individual, since it is necessary that the whole is prior to the part. For example, if the whole body is destroyed, there will be no foot or hand . . . Here is the proof that the state is a creation of nature and prior to the individual: the individual, when isolated, is not self-sufficient and, therefore, he is like a part in relation to the whole. But he who is unable to live in society, or who has no need because he is sufficient for himself, must be either a beast or a god: he is no part of a state. A social instinct is implanted in all men by nature, and he who first founded the state was the greatest of benefactors. For man, when perfected, is the best of animals; but, when separated from law and justice, he is the worst of all. Nothing is so difficult to subdue as injustice in weapons: but these weapons man is born with, namely, prudence and valor, which he may apply to the most opposite purposes. For he who abuses them will be the most wicked, the most cruel, the most lustful, and most gluttonous being imaginable. But justice is the bond of people in states; it is the criterion of what is right, and by its rules the state is ordered. [Politics, 1.2]

Natural Slaves and Rules

Is anyone designed by nature to be a slave, and for whom such a condition is advantageous and right, or rather is not all slavery a violation of nature? There is no difficulty in answering this question, on grounds both of reason and of fact. For that some should rule and others be ruled is a thing not only necessary, but useful. From the hour of their birth, some are marked out for subjection, others for rule. There are many kinds of rulers and subjects. (And, that rule is the better when exercised over better subjects. For example, to rule over men is better than to rule over wild beasts; for the work is better which is executed by better workmen, and where one man rules and another is ruled, they may be said to have a work). A distinction between the ruling and the subject element comes to light in all things which form a composite whole and which are made up of parts, whether continuous or discrete. Such a duality exists in living creatures, but not in them only. It originates in the constitution of the universe. Even in things that have no life, there is a ruling principle, as in a musical scale. But we are wandering from the subject. We will therefore restrict ourselves to the living creature, which, in the first place, consists of soul and body: and of these two, the one is by nature the ruler, and the other the subject. [Politics, 1.5]


Epic poetry and tragedy, comedy also and empassioned poetry, and the music of the flute and of the lyre in most of their forms, are all in their general conception modes of imitation. They differ, however, from one another in three respects: the medium, the objects, the manner of imitation, being in each case distinct. There are people who, by conscious art or mere habit, imitate and represent various objects through the medium of color and form, or again by the voice. So in the arts above mentioned, taken as a whole, the imitation is produced by rhythm, language, or ‘harmony,’ either singly or combined. Thus in the music of the flute and of the lyre, ‘harmony’ and rhythm alone are employed. This is also the case in other arts, such as that of the shepherd’s pipe, which are essentially similar to these. In dancing, rhythm alone is used without ‘harmony’; for even dancing imitates character, emotion, and action, by rhythmical movement. [Poetics, 1]

Since the objects of imitation are men in action, and these men must be either of a higher or a lower type (for moral character mainly answers to these divisions, goodness and badness being the distinguishing marks of moral differences), it follows that we must represent men either as better than in real life, or as worse, or as they are. It is the same in painting. . . . The same distinction marks off tragedy from comedy; the one aims at representing men as worse, the other as better than in actual life. [Poetics, 2]

Tragedy, then, is an imitation of an action that is serious, complete, and of a certain magnitude; in language embellished with each kind of artistic ornament, the several kinds being found in separate parts of the play; in the form of action, not of narrative; through pity and fear effecting the proper catharsis (or purging) of these emotions. [Poetics, 6]


Ancient Greek Cynic from Sinope who defied convention and recommended that people live freely.

Anecdotes about Diogenes

On one occasion he saw a child drinking out of its hands, and so he threw away the cup which belonged to his wallet, saying, “That child has beaten me in simplicity.” He also threw away his spoon, after seeing a boy, when he had broken his vessel, take up his lentils with a crust of bread. And he used to argue thus, “Everything belongs to the gods; and wise men are the friends of the gods. All things are in common among friends; therefore everything belongs to wise men.” . . .

Plato denned man thus: “Man is a two-footed, featherless animal,” and was much praised for the definition; so Diogenes plucked a cock and brought it into his school, and said, “ This is Plato’s man.” On which account this addition was made to the definition, “With broad flat nails.” A man once asked him what was the proper time for supper, and he made answer, “If you are a rich man, whenever you please; and if you are a poor man, whenever you can.” When he was at Megara he saw some sheep carefully covered over with skins, and the children running about naked; and so he said, “It is better at Megara to be a man’s ram, than his son.” Having lighted a candle in the day time, he said, “I am looking for a man.” On one occasion he stood under a fountain, and as the bystanders were pitying him, Plato, who was present, said to them, “If you wish really to show your pity for him, come away;” intimating that he was only acting thus out of a desire for notoriety. . . .

Once at a banquet, some of the guests threw him bones, as if he had been a dog; so lie, as he went away, put up his leg against them as if he had been a dog in reality. . . .

A man once reproached him with his banishment, and his answer was, “You wretched man, that is what made me a philosopher.” And when, on another occasion, some one said to him, “The people of Sinope condemned you to banishment,” he replied, “And I condemned them to remain where they were.” . . .

When Plato was discoursing about his “Forms,” and using the nouns “ tableness “ and “cupness;” “Oh Plato!” interrupted Diogenes, “ see a table and a cup, but I see no tableness or cupness.” Plato made answer, “That is natural enough, for you have eyes, by which a cup and a table are contemplated; but you have not intellect, by which tableness and cupness are seen.” . . .

Once Alexander the Great came and stood by him, and said, “I am Alexander, the great king.” “And I,” said he, “am Diogenes the dog.” And when he was asked to what actions of his it was owing that he was called a dog, he said, “Because I grovel upon those who give me anything, and bark at those who give me nothing, and bite the scoundrels.” [Diogenes Laertius, Lives of Eminent Philosophers, Diogenes of Sinope, 33]

EPICURUS (341–270 BCE)

Ancient Greek philosopher from Samos who espoused atomism and emphasized achieving happiness by minimizing pain and pursuing pleasure.

Atoms in a Vacuum

The atoms are in a continual state of motion. Among the atoms, some are separated by great distances, others come very near to one another in the formation of combined bodies, or at times are enveloped by others which are combining. But in this latter case they, nevertheless, preserve their own peculiar motion, thanks to the nature of the vacuum, which separates the one from the other, and yet offers them no resistance. The solidity which they possess causes them, while knocking against one another, to react the one upon the other; till at last the repeated shocks bring on the dissolution of the combined body; and for all this there is no external cause, the atoms and the vacuum being the only causes. [Letter to Herodotus]


One must not forget that the production of images is simultaneous with the thought; for from the surface of the bodies images of this kind are continually flowing off in an insensible manner indeed, because they are immediately replaced. They preserve for a long time the same disposition, and the same arrangement that the atoms do in the solid body, although, notwithstanding, their form may be sometimes altered. The direct production of images in space is equally instantaneous, because these images are only light substances destitute of depth. [Letter to Herodotus]

Slight Swerve

When bodies are borne downwards sheer through void by their own weights, at quite uncertain times and uncertain spots they push themselves a little from their course: you just and only just can call it a change of inclination. If they were not used to swerve, they would all fall down, like drops of rain, through the deep void, and no clashing would have been begotten nor blow produced among the first-beginnings: thus nature never would have produced anything. [Lucretius, On the Nature of Things, 2]

Free Will

What causes this free will for living things all over the earth? From what source, I ask, is it extracted from fate, this will whereby we move forward, where pleasure leads each one of us, and swerve likewise in our motions neither at determined times nor in a determined direction of place, but just where our mind has carried us? For without doubt it is one’s own will which gives to each one a start for this movement, and from the will the motions pass flooding through the limbs. . . . But the very mind feels no some necessity within in doing all things, and is not constrained like a conquered thing to bear and suffer. This is brought about by the tiny swerve of the first-beginnings in no determined direction of place and at no determined time. [Lucretius, On the Nature of Things, 2]


We know there are Gods, since we have distinct knowledge of them. But they are not of the nature that people in general attribute to them, and they do not respect them in a way that agrees with the ideas that they entertain of them. A person is not irreverent for rejecting the Gods believed in by the masses, but, rather, is irreverent for applying to the Gods the opinions entertained of them by the masses. . . . [Letter to Menoeceus]


Accustom yourself to think that death is a matter that should not concern us. For all good and all evil depend on sensation, and death is only the removal of sensation. Accordingly, the correct view of the fact that death is no concern of ours makes the mortality of life pleasant to us, not because it gives us limitless time, but because it relieves us of the longing for immortality. There is nothing terrible in living to a person who rightly understands that there is nothing terrible in ceasing to live. Only a foolish person says that he fears death, not because it will cause him pain when it occurs, but because it pains him while he anticipates it. It is quite absurd if something that is not distressful when present should distress a person when it is only expected. . . . [Letter to Menoeceus]


We affirm that pleasure is the beginning and end of the good life. We recognize pleasure as the first good, being natural to us, and it is from pleasure that we begin every choice and avoidance. It is also to pleasure that we return, using it as the standard by which we judge every good.

While pleasure is the first good and natural with us, we do not choose every pleasure, but at times we pass over many pleasures when any difficulty is likely to result from them. . . .

When we say that pleasure is the chief good, we are not speaking of the pleasures of the degenerate person, or those which involve sensual enjoyment—as some think who are ignorant or oppose our opinions, or else distort them. Rather, we mean the freedom of pain from the body and turmoil from the mind. Life is not made pleasant through continued drinking and partying, or sexual encounters, or feasts of fish and other such things as a costly banquet offers. It is sober contemplation which examines into the reasons for all choice and avoidance, and which chases away vain opinions from which the greater part of the confusion arises which troubles the mind. [Letter to Menoeceus]


Hellenistic school founded by Zeno of Citium (334–262 BCE) that emphasizes resigning oneself to fate.

Three Parts of Philosophy

The Stoics divide philosophical knowledge into three parts: one part relates to physics, one to ethics, and one to logic. Zeno of Citium was the first who made this division in his treatise On Reason. Chrysippus followed him in the first book of his treatise On Reason, and in the first book of his treatise On Nature. This was also done by Apollodorus, by Syllus in the first book of his Introduction to the Doctrines of the Stoics, by Eudromus in his Ethical Elements, by Diogenes the Babylonian, and Posidorus. Now, these divisions are called topics by Apollodorus, species by Chrysippus and Eudromus, and genera by all the rest. They compare philosophy to an animal, likening logic to the bones and sinews, physics to the fleshy parts, and ethical philosophy to the soul. They also compare it to an egg, calling logic the shell, and ethics the white, and physics the yolk. Similarly, they compare it to a garden in which logic is the fence which goes round it, physics are the soil or the fruit-trees, and ethics is the fruit. Again, they compare it to a city fortified by walls, and regulated by reason. However, some of them say that no one part is preferred to another, but they are all combined and united inseparably, and so they treat them all in combination. Others, though, class logic first, physics second, and ethics third, as Zeno does in his treatise on reason, and in this he is followed by Chrysippus, and Archidemus, and Eudromus. [Diogenes Laertius, Lives of Eminent Philosophers, Zeno, 33]

Logical Propositions

Of propositions which are not simple, the combined proposition is . . . that which is held together by the copulative conjunction “if.” This conjunction professes that the second member of the sentence follows the first, as for instance, “If it is day, it is light.” That which is adjunctive is . . . an axiom which is made to depend on the conjunction “since”, beginning with an axiom and ending in an axiom, as for instance, “Since it is day, it is light.” And this conjunction professes both that the second portion of the proposition follows the first, and the first is true. A connected proposition is connected by some copulative conjunctions, as for instance, “It both is day, and it is light.” A disjunctive proposition is disconnected by the disjunctive conjunction “or” as for instance, “It is either day or night.” This proposition professes that one or other of these propositions is false. A causal proposition is connected by the word, “because;” as for instance, “Because it is day, it is light.” For the first is, as it were, the cause of the second. An augmentative proposition, which explains the greater, is construed with an augmentative particle, and which is placed between the two members of the proposition, as for instance, “It is rather day than night.” The diminutive proposition is, in every respect, the exact contrary of the preceding one, as for instance, “It is less night than day.” Again, at times, axioms or propositions are opposed to one another in respect of their truth and falsehood, when one is an express denial of the other; as for instance, “It is day” and, “It is not day.” [Diogenes Laertius, Lives of Eminent Philosophers, Zeno, 48]

Logical Arguments

An argument, as Criuis says, is that which is composed of a major premise, a minor premises, and a conclusion. For example, “If it is day, it is light;” “But it is day, therefore it is light.” For the major premise, is, “If it is day, it is light.” The minor premise is, “It is day.” The conclusion follows, “Therefore it is light.” The mode of a proposition is, as it were, a figure of an argument, as for instance, such as this, “If it is the first, it is the second; but it is the first, therefore it is the second.”

A conditional syllogism is that which is composed of both the preceding arguments as for instance, “If Plato is alive, Plato breathes; but the first fact is so, therefore so is the second.” And this conditional syllogism has been introduced for the sake, in long and complex sentences, of not being forced to repeat the assumption, as it was a long one, and also the conclusion; but of being able., instead, to content one’s self with summing it up briefly thus, “The first case put is true, therefore so is the second.” . . .

The fifth kind that is not demonstrative, is that in which the whole argument consists of a disjunctive proposition, and the opposite of one of the terms, and then one makes the conclusion identical with the remainder; as, for instance, “It is either day or night; but it is not night; therefore it is day.” [Diogenes Laertius, Lives of Eminent Philosophers, Zeno, 49]


Zeno illustrated this by the action of his hand. For showing his hand open to view with the fingers stretched out, perception, said he, is like this. Then, closing his fingers slightly, assent is like this. Next, entirely closed together his fingers and doubling his fist, he declared this position to resemble the mental act of comprehension; from that simile he also gave a new name to that mental act, calling it “grasping”. Again when he had brought up his left hand and had tightly and powerfully closed it over the other fist, he said that knowledge was like that, and that no one was able to attain to knowledge but the wise person. [Cicero, Academics, 2.4]

Physics: God and Fate

The Stoics teach that God is unity, and that he is called Mind, and Fate, and Jupiter, and by many other names besides. As he was in the beginning by himself, he turned into water the whole substance which pervaded the air. Just as the seed is contained in the fruit, so too, he being the seminal principle of the world, remained behind in moisture, making matter fit to be employed by himself in the production of those things which were to come after. Then he made the four elements, fire, water, air, and earth. . . .

[The Stoics] say that all things are produced by fate. Fate is the connecting cause of existing things, or the reason according to which the world is regulated. [Diogenes Laertius, Lives of Eminent Philosophers, Zeno, 68, 74]

Ethics: Living According to Universal Nature

In his treatise On Human Nature, Zeno was the first writer who said that the chief good was to live according to nature. This means living according to virtue, for nature leads us to this point. . . . Again, to live according to virtue is the same thing as living according to one’s experience of those things which happen by nature. Our individual natures are all parts of universal nature. Because of this, the chief good is to live in a manner that corresponds to nature, that is, that corresponds both to one’s own nature and to universal nature. This also means doing none of those things which the common law of humankind typically forbid. The common law is identical with that right reason which pervades everything, being the same with Jupiter, who is the regulator and chief manager of all existing things. We are to do everything in such a way that the capacity of each individual is in harmony with respect to the will of the universal governor and administrator of all things. This constitutes the virtue of the happy person and the good life. Diogenes, accordingly, says expressly that the chief good is to act according to sound reason in our selection of things according to our nature. [Diogenes Laertius, Lives of Eminent Philosophers, Zeno, 53]

Chrysippus: Free Will and Necessity

  1. Chrysippus, rejecting necessity [regarding choice], yet believing that nothing can happen without pre-existent causes, distinguishes causes into two kinds, in order to preserve the doctrine of fate, and yet avoid that of necessity [regarding choice]. There are, first, certain absolute primary causes, and, second, certain secondary proximate causes. When, therefore, we assert that all things happen by prior causes, we do not so much allude to these absolute or primary causes, as to the secondary and proximate ones. He therefore meets the consequence which I have just mentioned in this manner. If, says he, everything happens by fate, I grant that all happens by pre-existent causes; but these pre-existent causes are not primary, but secondary. And if these latter ones are not in our power, we can no longer maintain that appetite itself is in our power. But this must needs be the case, if we say that all happens by primary causes, since these causes being beyond our control, appetite is likewise beyond our control.

Those, therefore, who thus introduce fate, and join necessity [of choice] with it, rush wildly into this absurd consequence, namely, the destruction of free-will. But those who admit pre-existent causes without supposing them primary, have no such error to fear. In fact, nothing is more natural, according to these philosophers, than the manner in which the sentiments are produced by pre-existent causes. They grant that sentiments cannot arise without some corresponding action of the sense, yet they say that this action, having a secondary proximate cause (and not a primary one), takes place as Chrysippus conjectures. It’s not that this sentiment can arise without some extrinsic cause, (for sentiment and sensation are connected,) but the causal force is perpetuated, as in the case of a revolving wheel or top, which cannot begin to move until the final impulse is given to them. But after they have received it, they continue their gyrations according to their form.

  1. He says it is like a man who pushing a cylinder gives it a principle of motion, but not immediately that of revolution. Similarly an object strikes our sense and conveys its image to our mind, yet leaves us free to form our specific sentiment concerning it. It has been said in the case of the cylinder which is set in motion from without, it will continue for the future to move according to its own proper force and nature. But if any effect were produced without a prior cause, it would be true that all things happen by fate. If, however, it is probable that everything which happens has evidently a prior cause, what reason can be given why we should not admit that all things happen by fate, provided it is understood what the distinction and dissimilarity of causes is?

Following this explanation of Chrysippus, if those who deny that our sentiments are the effects of fate were to concede that they are not produced without a prior impression made on our senses, that would be one thing. But if they grant that a prior impression is made on the sense, and yet that the sentiments are not the effects of fate, since the proximate cause does not excite them specifically, both parties will agree to such a statement. For Chrysippus, in granting that the proximate cause of sentiment is in the impression made on the sense, does not imply that this was the necessary cause of its specific character. So that though all happens by fate, he still denies that all happens by necessary and compulsory causes. And they who differ from him, granting that no sentiment arises without a corresponding motion of sense, declare that if all happens by fate in such a manner that nothing takes place without a pre-existent cause, we must needs admit that all things take place by fate. Thus we may understand how both these contending disputants, when they have fairly explained their systems, arrive at the same essential result, and only differ in terms. And since the main points are admitted by both sides, we may affirm with confidence that when certain causes precede certain effects we cannot hinder these effects from happening. In other cases, on the contrary, though certain causes pre-exist, we have the molding of their effects in our own power, Such is the distinction recognized by both sides; but some imagine that those things whose causes so precede as to deprive us of the power of molding the effect, are submitted to the empire of fate, but that those which depend on ourselves are free from it. [Cicero, On Fate, 18, 19]

Epictetus: Things in our Control

Some things are in our control and others not. Things in our control are opinion, pursuit, desire, aversion, and, in a word, whatever are our own actions. Things not in our control are body, property, reputation, career, and, in one word, whatever are not our own actions. The things in our control are by nature free, unrestrained, unhindered; but those not in our control are weak, slavish, restrained, belonging to others. Remember, then, that if you suppose that things which are slavish by nature are also free, and that what belongs to others is your own, then you will be hindered.

  1. With regard to whatever objects give you delight, are useful, or are deeply loved, remember to tell yourself of what nature they are, beginning from the most insignificant things. If, for example, you are fond of a specific cup, remind yourself that it is merely a cup which you are fond of. Then, if it breaks, you will not be disturbed. If you kiss your child or your wife, say that you only kiss things that are mortal, and thus you will not be disturbed if either of them dies.
  2. Consider when, on a voyage, your ship is anchored. If you go on shore to get water you may along the way amuse yourself with picking up a shellfish, or a truffle. However, your thoughts and continual attention ought to be bent towards the ship, waiting for the captain to call on board. You must then immediately leave all these things, otherwise you will be thrown into the ship, bound neck and feet like a sheep. So it is with life. If, instead of an onion or a shellfish, you are given a wife or child, that is fine. But if the captain calls, you must run to the ship, leaving them, and do not concern yourself with them. But if you are old, never go far from the ship, for fear that when you are called you should be unable to come in time.
  3. Remember that you must behave in life as at a dinner party. Is anything brought around to you? Put out your hand and take your share with moderation. Does it pass by you? Don’t stop it. Is it not yet come? Don’t stretch your desire towards it, but wait till it reaches you. Do this with regard to children, to a wife, to careers, to riches, and you will eventually be a worthy partner of the feasts of the gods. And if you don’t even take the things which are set before you, but are able even to reject them, then you will not only be a partner at the feasts of the gods, but also of their empire. For, by doing this, Diogenes, Heraclitus and others like them, deservedly became, and were called, divine.
  4. Remember that you are an actor in a drama which depends upon the judgment of the author. If he wants it short, then it is short; if long, then it is long. If it is his pleasure that you should act a poor man, a cripple, a governor, or a private person, see that you act it naturally. For it is your job to act well the role that is assigned you; it is another’s job to choose your role. [Epictetus, Manual]


Hellenistic school founded by Pyrrho (c.365-c.275 BCE) that emphasizes doubting everything as a means of attaining tranquility and happiness.

Pyrrho: Suspending Judgment

Pyrrho introduced the doctrine of incomprehensibility, and of the necessity of suspending one’s judgment. . . . He used to say that nothing was honorable, or disgraceful, or just, or unjust. And on the same principle he asserted that there was no such thing as downright truth, but that men did everything in consequence of custom and law. He said that nothing was any more this than that. His life corresponded to his principles. He never shunned anything, and never guarded himself against anything he encountered, such as wagons, cliffs, dogs, and things of that sort. Disregarding his senses in this way, he used to be saved . . . by his friends who accompanied him. . . . He studied philosophy on the principle of suspending his judgment on all points, but without ever acting in an imprudent manner, or doing anything without proper consideration. [Diogenes Laertius, Lives of Eminent Philosophers, “Pyrrho,” 3]

Sextus Empiricus: Skepticism and Tranquility

Skepticism is an ability to place appearances in opposition to judgments in any way whatever. By balancing reasons that are opposed to each other, we first reach the state of suspension of judgment, and afterwards that of tranquility. . . .

Skepticism arose in the beginning from the hope of attaining tranquility. People of the greatest intelligence were perplexed by the contradiction of various things, and being at a loss what to believe, they began to question what things are true, and what false. They then hoped to attain tranquility through some solution. The primary principle of Skepticism, then, is to oppose every argument by one of equal weight, and in this way we finally reach the position where we have no dogmas. . . .

Those who say that the Skeptics deny appearances are ignorant of our teachings. For as I said before, we do not deny the sensations which we think we have, and which lead us to assent involuntarily to them; we accept that we have appearances. When we are ask whether the object is such as it appears to be, we concede that it appears so and so; however, while we do not question the phenomenon, we do question what is asserted about the phenomenon, and that is different from doubting the phenomenon itself. For example, it appears to us that honey is sweet. This we concede, for we experience sweetness through sensation. We doubt, however, whether it is sweet by reason of its essence, which is not a question of the phenomenon, but of that which is asserted of the phenomenon. . . .

Since tranquility follows the suspension of judgment in regard to everything, it is important for me to explain how this suspension of judgment takes place. Generally speaking, it occurs by placing things in opposition to each other. We either place appearances in opposition to appearances, or thoughts in opposition to thoughts, or some combination of these. For example, we place appearances in opposition to appearances when we say that this tower appears round from a distance but square when near by. . . . [Sextus Empiricus, Outlines of Pyrrhonism, 1.1-13]

Sextus Empiricus: Ten Methods of Skepticism

Certain Methods were commonly handed down by the older Skeptics, by means of which suspension of judgment seems to take place. They are ten in number, and are synonymously called “arguments” and “points.” They are these: the first is based upon the differences in animals; the second upon the differences in men; the third upon the difference in the constitution of the organs of sense; the fourth upon circumstances; the fifth upon position, distance, and place; the sixth upon mixtures; the seventh upon the quantity and constitution of objects; the eighth upon relation; the ninth upon frequency or rarity of occurrences; the tenth upon systems, customs, laws, mythical beliefs, and dogmatic opinions. I have made this order myself. . . .

The first Method, I said, is the one based upon the differences in animals, and according to this Method, different animals do not get the same ideas of the same objects through the senses. This we conclude from the different origin of the animals, and also from the difference in the constitutions of their bodies. . . . For how can it be said that shellfish, birds of prey, animals covered with spines, those with feathers and those with scales would be affected in the same way by the sense of touch? And how can the sense of hearing perceive alike in animals which have the narrowest auditory passages, and in those that are furnished with the widest, or in those with hairy ears and those with smooth ones? For even humans bear differently when we partially stop up the ears, from what we do when we use them naturally. . . . We therefore have no evidence according to which we can give preference to our own ideas over those of so-called irrational animals. Since ideas differ according to the difference in animals, and it is impossible to judge them, it is necessary to suspend the judgment in regard to external objects.

The tenth Method is one principally connected with morals, relating specifically to codes of conduct, customs, laws, mythical beliefs, and dogmatic opinions. . . . We sometimes place each of these things in opposition to itself, and other times in opposition to each one of the others. For example, we place a custom in opposition to another custom as follows. Some of the Ethiopians tattoo new-born children, but we do not. The Persians think it is appropriate to have a garment of many colors reaching to the feet, but we think it is inappropriate. People from India have sex with their women in public, but most of the other nations find that shameful.

Thus, seeing so great a diversity of practices, the skeptic suspends judgment as to the natural existence of anything good or bad, or generally to be done. [Sextus Empiricus, Outlines of Pyrrhonism, 1.14]

Skepticism and Self-Refutation

[According to the Skeptics] to any assertion there is a contrary assertion opposed, which, after having destroyed all others, turns itself against itself, and destroys itself. This resembles, as it were, those cathartic medicines which, after they have cleansed the stomach, then discharge themselves, and are got rid of. But the dogmatic philosophers criticize that all these reasonings are so far from overturning the authority of reason that they confirm it. To this the Skeptics reply, that they only use reason as an instrument, because it is impossible to overturn the authority of reason without using reason. Similarly if we assert that “there is no such thing as space,” we must use the word “space,” but using it not dogmatically, but demonstratively. Again, if we assert that “nothing exists according to necessity,” it is unavoidable that we use the word “necessity.” . . .

The dogmatical philosophers arguing against the Skeptics, say that they also adopt spurious and pronounce positive dogmas. For where they think that they are refuting others they are convicted: in the very act of refutation, they assert positively and dogmatize. For when they say that they define nothing, and that every argument has an opposite argument, they at the same time give a positive definition, and assert a positive dogma. But Skeptics reply to these objectors. As to the things which happen to us as men, we admit the truth of what you say; for we certainly do know that it is day, and that we are alive. We also admit that we know many other of the phenomena of life. But with respect to those things as to which the dogmatic philosophers make positive assertions, saying that they are comprehended, we suspend our judgment on the ground of their being uncertain, and that we know nothing but the passions. We confess that we see, and we are aware that we comprehend that such a thing is the fact, but we do not know how we see, or how we comprehend. Also, we state in the way of narrative that this appears white, without asserting positively that it really is so. With respect to the assertion, “We define nothing,” and other sentences of that sort, we do not pronounce them as dogmas. For to say that is a different kind of statement from saying that the world is spherical; for the one fact is not evident, while the other statements are mere admissions. While, therefore, we say that we define nothing, we do not even say that as a definition.

Again, the dogmatic philosophers say that the Skeptics overthrow all life, when they deny every thing of which life consists. But the Skeptics say that they are mistaken; for they do not deny that they see, but that they do not know how it is that they see. For, say they, we assert what is actually the fact, but we do not describe its character. Again, we feel that fire burns, but we suspend our judgment as to whether it has a burning nature. Also, we see whether a person moves, and that a man dies; but how these things happen we know not. Therefore, say they, we only resist the uncertain deductions which are put by the side of evident facts. For when we say that an image has projections, we only state plainly what is evident; but when we say that it has not projections, we no longer say what appears evident, but something else. [Diogenes Laertius, Lives of Eminent Philosophers, “Pyrrho” 8, 11]

PLOTINUS (204-270 CE)

Hellenistic philosopher inspired by Plato who held that all levels of reality emanate from the One.

The Three Hypostases

5:1:6. The mind demands the existence of these [three] Beings, but it is still in trouble over the problem endlessly debated by the most ancient philosophers: from such a unity as we have declared The One to be, how does anything at all come into substantial existence, any multiplicity, dyad, or number? Why has the Primal not remained self-gathered so that there is none of this profusion of the multiplicity which we observe in existence and yet are compelled to trace to that absolute unity? . . .

All existences, as long as they retain their character, produce about themselves, from

their essence, in virtue of the power which must be in them some necessary, outward-facing hypostasis continuously attached to them and representing in image the producing archetypes. Thus fire gives out its heat; snow is cold not merely to itself; fragrant substances are a notable instance; for, as long as they last, something is diffused from them and perceived wherever they are present.

Again, all that is fully achieved produces. Therefore the eternally achieved produces eternally an eternal being. At the same time, the offspring is always minor. What then are we to think of the All-Perfect but that it can produce nothing less than the very next greatest than itself. The greatest, after the divine unity, must be the Divine Mind. It must be the second of all existence, for it is that which sees The One on which alone it leans while the First has no need whatever of it. The offspring of the prior to Divine Mind can be no other than that Mind itself and thus is the loftiest being in the universe, all else following upon it the soul, for example, being an utterance and act of the Intellectual-Principle as that is an utterance and act of The One. But in soul the utterance is obscured, for soul is an image and must look to its own original: that Principle, on the contrary, looks to the First without mediation thus becoming what it is and has that vision not as from a distance but as the immediate next with nothing intervening, close to the One as Soul to it.

The offspring must seek and love the parent; and especially so when parent and offspring are alone in their sphere. When, in addition, the parent is the highest good, the offspring [inevitably seeking its Good] is attached by a bond of sheer necessity, separated only in being distinct. [Enneads]

Returning to the Beauty of the One

1:6:7. We must ascend again towards the Good, the desired of every Soul. Anyone that has seen This, knows what I mean when I say that it is beautiful. Even the desire of it is to be desired as a Good. To attain it is for those that will take the upward path, who will set all their forces towards it, who will divest themselves of all that we have put on in our descent.

  1. But what must we do? How lies the path? How come to vision of the inaccessible Beauty, dwelling as if in consecrated precincts, apart from the common ways where all may see, even the profane? He that has the strength, let him arise and withdraw into himself, foregoing all that is known by the eyes, turning away for ever from the material beauty that once made his joy. . . . “Let us flee then to the beloved Fatherland”: this is the soundest counsel. But what is this flight? . . . What then is our course, what the manner of our flight? This is not a journey for the feet; the feet bring us only from land to land; nor need you think of coach or ship to carry you away; all this order of things you must set aside and refuse to see: you must close the eyes and call instead upon another vision which is to be waked within you, a vision, the birth-right of all, which few turn to use.
  2. And this inner vision, what is its operation? Newly awakened it is all too feeble to bear the ultimate splendor. Therefore the Soul must be trained to the habit of remarking, first, all noble pursuits, then the works of beauty produced not by the labor of the arts but by the virtue of men known for their goodness: lastly, you must search the souls of those that have shaped these beautiful forms. But how are you to see into a virtuous soul and know its loveliness?

Withdraw into yourself and look. And if you do not find yourself beautiful yet, act as does the creator of a statue that is to be made beautiful: he cuts away here, he smoothes there, he makes this line lighter, this other purer, until a lovely face has grown upon his work. So do you also: cut away all that is excessive, straighten all that is crooked, bring light to all that is overcast, labor to make all one glow of beauty and never cease chiseling your statue, until there shall shine out on you from it the godlike splendor of virtue, until you shall see the perfect goodness surely established in the stainless shrine.

When you know that you have become this perfect work, when you are self-gathered in the purity of your being, nothing now remaining that can shatter that inner unity. . . Now call up all your confidence, strike forward yet a step you need a guide no longer strain, and see. This is the only eye that sees the mighty Beauty. . . . So, rising, the Soul will come first to the Intellectual-Principle and survey all the beautiful Ideas in the Supreme and will affirm that this is Beauty, that the Ideas are Beauty. For by their efficacy comes all Beauty else, but the offspring and essence of the Intellectual-Being. What is beyond the Intellectual-Principle we affirm to be the nature of Good radiating Beauty before it. [Enneads]

The Unspeakable Nature of the One

5:3:12. The One, as above knowledge, is above knowing. Above all need, it is above the need of the knowing which pertains solely to [things that have a] secondary nature. . . .

  1. Thus The One is in truth beyond all statement: any affirmation is of a thing; but the all-transcending, resting above even the most august divine Mind, possesses alone of all true being, and is not a thing among things; we can give it no name because that would imply predication: we can but try to indicate, in our own feeble way, something concerning it: when in our perplexity we object, “Then it is without self-perception, without self-consciousness, ignorant of itself”; we must remember that we have been considering it only in its opposites. If we make it knowable, an object of affirmation, we make it a multiplicity; and if we allow knowledge in it we make it at that point indigent: supposing that in fact intellection accompanies it, intellection by it must be superfluous. . . .
  2. How, then, do we ourselves speak about it? No doubt we deal with it, but we do not state it; we have neither knowledge nor thought of it. But in what sense do we even deal with it when we have no hold upon it? We do not, it is true, grasp it by knowledge, but that does not mean that we are utterly void of it. We hold it not so as to state it, but so as to be able to speak about it. And we can and do state what it is not, while we are silent as to what it is. We are, In fact, speaking of it in the light of what comes after it. Unable to state it, we may still possess it. [Enneads]


Philosophy within India’s Hindu religion beginning around 500 BCE that emphasizes the pantheistic notion of the Self-God and yoga methods for release from rebirth.

The Self-God

Bees make honey by collecting the juices of distant trees and reducing the juices into one form. These juices have no discrimination and do not say “I am the juice of this tree or that tree.” In the same manner, when all these creatures merge with Being [either in deep sleep or in death], they do not know that they merged with Being. Whatever these creatures are here — whether a lion, a wolf, a boar, a worm, a fly, a gnat, or a mosquito — they become that again and again. Everything that exists has as its soul that which is the finest essence. It is Reality. It is the Atman, and you are that, my son. . . . The eastern rivers [like the Ganges] flow toward the east, and the western rivers [like the Sindhu] flow toward the west. They go from sea to sea. They become the sea. When those rivers are in the sea, they do not say “I am this or that river.” In the same manner, when all these creatures come forth from Being, they do not know that they have come forth from Being. Whatever these creatures are here — whether a lion, a wolf, a boar, a worm, a fly, a gnat, or a mosquito — they become that again and again. Everything that exists has as its soul that which is the finest essence. It is Reality. It is the Atman, and you are that, my son. [Chandogya Upanishad, 6:9-11]

We may understand that the Atman is sitting in the chariot, the body is the chariot, the intellect (buddhi) is the charioteer, and the mind is the reins. The senses are the horses, the objects of the senses are their roads. When he [i.e., the highest Atman] is in union with the body, the senses, and the mind, then wise people call him the Enjoyer. If someone has no understanding and his mind [i.e., the reins] is never firmly held, then his senses, like vicious horses, are unmanageable. But if someone has understanding and his mind is always firmly held, then his senses are under control, like good horses of a charioteer. If someone has no understanding and is unmindful and always impure, then he never reaches that place, but enters into the cycle of births. But if someone has understanding and is mindful and always pure, then he indeed reaches that place, and from there he is not born again. And if someone has understanding for his charioteer, and who holds the reins of the mind, then he reaches the end of his journey, and that is the highest place of Vishnu. [Katha Upanishad]

Release and Reincarnation

As a person throws off worn-out garments and takes new ones, so too the dweller in the body throws off worn-out bodies and enters into others that are new. Weapons do not pierce him, fire does not burn him, water does not make him wet, and wind does not dry him away. He cannot be pierced, burned, made wet, or dried. He is perpetual, all pervasive, stable, immovable, and ancient. He is called unmanifest, unthinkable, and immutable. Therefore, knowing him as such, you should not grieve. Or if you think of him as being constantly born and constantly dying, even then, you should not grieve. For death is certain for those who are born, and birth is certain for those who are dead. Therefore, you should not grieve over the inevitable. [Bhagavad Gita, 2]

Action Yoga

The foolish utter flowery speech, and rejoice in the letter of the Vedas [i.e., Hindu scriptures]. For them there is nothing but a desire for the self with only the intent on reaching heaven. They prescribe many ceremonies to attain pleasure and power, but rebirth is the fruit of their actions. . . . .

Your business is with actions only, and never with the fruits of your actions. So do not let the fruit of your actions motivate you, and do not be attached to inaction. Perform action, Arjuna, dwelling in the union of the divine. Renounce attachments, and balance yourself evenly between success and failure. Equilibrium is called Yoga. Action is inferior to discrimination; so, take refuge in the intellect. People are pitiable who work only for its fruits. By disciplining one’s intellect, one abandons both good and evil deeds. Therefore you should cling to [karma] Yoga, which is skill in action. The wise disciplined their intellect, renounced the fruits of their actions, released themselves from the bonds of birth, and attained a state of bliss. When your intellect escapes from the tangle of delusion, then you too will be indifferent about what you had heard and will hear [in the Vedas]. . . .

When a person abandons all the desires of his heart and is satisfied in the Self and by the Self, then he is called “stable in mind.” A sage of stable mind is free from anxiety when surrounded by pains, is indifferent when surrounded by pleasures, and is freed from passion, fear and anger. He is without attachments on every side, whether desirable or undesirable, and neither likes nor dislikes. The person of understanding is well poised. Just as a tortoise pulls in all its limbs, the sage withdraws his senses from the objects, and his understanding is well poised. [Bhagavad Gita, 2]

Meditation Yoga

[Krishna:] He who performs his actions as a duty, independently of the fruit of the action, is an ascetic. He is a Yogi, and not the person who intentionally avoids actions such as lighting the sacred fire and performing the sacred rites. Understand that “Yoga” is renunciation, and no one becomes a Yogi without renouncing his will. … The Yogi should constantly engage himself in Yoga, staying in a secret place by himself, subduing his thoughts and self, and freeing himself from hope and greed. He should set up a fixed seat for himself in a pure place, which is neither too high, nor too low, made of a cloth, a black deerskin, and kusa grass, one over the other. Once there he should practice Yoga for the purification of the self; he should make his mind one-pointed, subduing his thoughts and the functions of his senses. He should hold his body, head and neck erect, immovably steady, looking at the point of his nose with an unseeing gaze. His heart should be serene, fearless and firm in the vow of renunciation. His mind should be controlled as he sits in harmony. In this manner he will think on me and aspire after me. Thus, always keeping the mind balanced, the Yogi, with the mind controlled, attains to the peace abiding in me, which culminates in release

Yoga is not for the person who eats too much or too little, or who sleeps too much or too little. Yoga kills all pain for the person who is moderate in eating, amusement, performing actions, sleeping, and waking. When his subdued thought is fixed on the Atman and free from desiring things, then we can say that he is harmonized. Just as a lamp in a windless place does not flicker, so too will the subdued thought of the Yogi be absorbed in the Yoga of the self. … The Yogi who harmonizes the self and puts away evil, will enjoy the infinite bliss of unity with the eternal Brahman. The self, harmonized by Yoga, sees the Atman abiding in all beings, and all beings in the Atman. Everywhere he sees the same thing. I will never lose hold of the person who sees me everywhere, and sees everything in me, and that person will never lose hold of me. Regardless of how else he may live, the Yogi lives in me who is established in unity and worships me abiding in all things. The perfect Yogi is the one who, established in unity, sees equality in everything, whether pleasant or painful.

[Arjuna:] You describe this Yoga as a unity. However, Krishna, I see no basis for it given the impermanence of thought. The mind is very restless. Indeed, it is impetuous, strong, and difficult to bend. Perhaps it is as hard to control as the wind.

[Krishna:] Undoubtedly, Arjuna, the mind is restless and hard to control. But it may be controlled with constant practice and dispassion. I think Yoga is hard to attain by an uncontrolled self. But for a controlled Atman, it is attainable by properly directing energy.

[Arjuna:] Suppose that a person has faith, but his mind is still uncontrolled and wanders away from Yoga, thus failing to attain perfection in Yoga. What is in store for him? He fails in his quest from Brahman, and thus fails both his earthy and spiritual quest. Please dispel my doubts, since only you are able to do this.

[Krishna:] No, he will not be lost in this life or the next. No one who does what is right will walk the path of destruction. Even if he fell from Yoga, by virtue of his good actions, he will be reborn in a pure and house, and may even be born into a family of wise Yogis. But this kind of birth is difficult to obtain in this world. In this reborn state, he retains the characteristics belonging to his previous body, and with these he again works for perfection. . . . [Bhagavad Gita, 6]

Vedanta: Sankara

When accepted as the doctrine of the Vedas, this doctrine of the individual soul having its Self in Brahman does away with the independent existence of the individual soul. This is just as the idea of the rope does away with the idea of the snake [for which the rope had been mistaken]. And if the doctrine of the independent existence of the individual soul has to be set aside, then the view of the entire phenomenal world having an independent existence must likewise be set aside insofar as it is based on the individual soul. But in addition to the element of unity, an element of manifoldness would have to be [falsely] assumed in Brahman only for the purpose of establishing the phenomenal world. . . .

Scriptural passages also declare that for people who see that everything has its Self in Brahman, [they also see that] the whole phenomenal world is non-existent, including actions, agents, and consequences of actions. Nor can it be said that this non-existence of the phenomenal world is declared by Scripture to be limited to certain states. For the passage “You are that” shows that the general fact of Brahman being the Self of all is not limited by any particular state.

… By quoting parallel instances of clay (and its various modifications), it may be objected that Scripture itself endorses a Brahman which is capable of modification. For we know from experience that clay and similar things do undergo modifications. In reply, this objection is without force. A number of scriptural passages deny all modifications of Brahman and thereby teach that it is absolutely changeless. Such passages are, “Indeed, Brahman is this great unborn Self, undecaying, undying, immortal, fearless.” … For we cannot ascribe to one Brahman the two qualities of (a) being subject to modification and (b) being free from modification. And if you say, “Why should they not be both predicated of Brahman?” we reply that the qualification “absolutely changeless” precludes this. For the changeless Brahman cannot be the substratum of varying attributes.

… In this manner the Vedanta texts declare that, for those who have reached the state of truth and reality, the whole apparent world does not exist. The Bhagavad Gita also declares that in reality the relation of Ruler and ruled does not exist. Scripture as well as the Bhagavad Gita says that, on the other hand, all those distinctions are valid [only] as far as the phenomenal world is concerned. … Further, the view of Brahman as undergoing modifications will be of use [only] when closely reflecting on the Brahman-with-attributes (saguna). [Sankara, Commentary on the Vedanta Sutra 2:1:14]

Vedanta: Ramanuja

We cannot admit the claim that Scripture teaches that the cessation of ignorance springs only from the cognition of a Brahman devoid of all difference. Such a view is clearly denied by other scripture passages such …. Because Brahman is characterized by difference, all Vedic texts declare that final release results from the cognition of a qualified Brahman. And even those texts that describe Brahman by way of negation really aim at setting forth a Brahman that possesses attributes.

In texts such as “You are that” (tat tvam asi), the relation of the constituent parts is not meant to convey the idea of the absolute unity of an undifferentiated substance. On the contrary, the words “that” and “you” denote a Brahman distinguished by difference. The word “that” refers to Brahman as omniscient, etc., which had been introduced as the general topic of consideration in previous passages of the same section, such as “It thought, may I be many.” The word “you,” which stands in relation to “that,” conveys the idea of Brahman insofar as its body consists of the individual souls connected with non-intelligent matter. …

Moreover, it is not possible for ignorance to belong to Brahman, whose essential nature is knowledge, which is free from all imperfections, omniscient, comprising within itself all favorable qualities. However, ignorance would result from the absolute oneness of “that” and “you”. It [i.e., Brahman] would be the underlying strata of all those defects and afflictions which spring from ignorance. …

If, on the other hand, the text is understood to refer to Brahman as having the individual souls for its body, both words (“that” and “you”) keep their primary meaning. Thus, by making a declaration about one substance distinguished by two aspects, the text preserves the fundamental principle of “relation”. On this interpretation the text further implies that Brahman (free from all imperfection and comprising within itself all favorable qualities) is the internal ruler of the individual souls and possesses lordly power. [Ramanuja, Commentary on the Vedanta Sutra, 1.1.1]


Philosophy within India’s Buddhist religion beginning around 500 BCE that emphasizes nirvana as a means of eliminating desires that cause suffering.

Four Noble Truths.

Now this is the noble truth concerning suffering. Birth is attended with pain, decay is painful, disease is painful, and death is painful. Union with the unpleasant is painful, and separation from the pleasant is painful. Any craving that is unsatisfied is also painful. In brief, the five components which spring from attachment are painful. This then is the noble truth concerning suffering.

Now this is the noble truth concerning the origin of suffering. It is that thirst or craving which causes the renewal of existence, accompanied by sensual delight, and the seeking of satisfaction first here, then there. That is to say, it is the craving for the gratification of the passions, or the craving for a future life, or the craving for success in this present life. This then is the noble truth concerning the origin of suffering.

Now this is the noble truth concerning the elimination of suffering [i.e., the attainment of Nirvana]. It is the destruction of this very thirst, in which no passion remains. It is the laying aside of, the getting rid of, the being free from, and the harboring no longer of this thirst. This, then, is the noble truth concerning the destruction of suffering.

Now this is the noble truth concerning the path that leads to the elimination of suffering. It is the noble eightfold path.

There are two extremes, fellow monks, which a holy person should avoid: the habitual practice of … self-indulgence, which is vulgar and profitless … and the habitual practice of self-mortification, which is painful and equally profitless. There is a middle path discovered by the Tathagata [i.e., the Buddha] — a path which opens the eyes and bestows understanding which leads to peace of mind, to the higher wisdom, to full enlightenment, and to Nirvana. Truly, it is the noble eightfold path consisting of the following: Right views [free from superstition or delusion]; Right aims [high and worthy of the intelligent, earnest person]; Right Speech [kindly, open, and truthful]; Right Conduct [peaceful, honest, and pure]; Right livelihood [bringing no hurt or danger to living things]; Right effort [in self-training and self-control]; Right mindfulness [the active, watchful mind]; Right contemplation [earnest thought on the mysteries of life] This is the middle path, avoiding these two extremes. [Samyutta-nikaya 56:2]

Questions Which do not Lead to Enlightenment

[Malunkyaputta:] Reverend sir, I was just now in seclusion and plunged in meditation, when a thought occurred to my mind. There are theories that the Blessed One has left unexplained, and has set aside and rejected. They are, that the world is eternal, that the world is not eternal, … that the saint neither exists nor does not exist after death. The Blessed One does not explain these to me. …

[Buddha:] Suppose that a man had been wounded by an arrow thickly smeared with poison. When friends and relatives went to procure for him a physician, suppose the sick man said, “I will not have this arrow taken out until I have learned whether the man who wounded me belonged to the warrior caste, priestly caste, worker caste, or servant caste.” Or again, suppose he said, “I will not have this arrow taken out until I have learned the name of the man who wounded me, and to what clan he belongs.” Or again, suppose he said, “I will not have this arrow taken out until I have learned the whether the man who wounded me was tall, short, or middle height … or was black, white, or yellow skinned … or from this or that village, town or city ….” That man would die without ever having learned these things. Suppose similarly someone said “I will not lead the religious life under the Blessed One [i.e., the Buddha] until the Blessed One explained to me that the world is eternal or not eternal … or that the saint exists or does not exist after death.” That person too would die before the Tathagata [i.e, the Buddha] ever explained this to him.

The religious life does not depend on the dogma that the world is eternal, nor on the dogma that the world is not eternal. Whether the dogma obtains that the world is eternal or that the world is not eternal, there still remains birth, old age, death, sorrow, lamentation, misery, grief, and despair; and I prescribe the extinction of these in the present life. So, always bear in mind what it is that I have not explained, and what it is that I have explained. And what have I not explained? I have not explained that the world is eternal, … that the world is not eternal, … and that the saint neither exists nor does not exist after death. And why have I not explained this? Because this does not profit us, it has nothing to do with the fundamentals of religion, and does not tend to aversion, absence of passion, cessation, calm, the supernatural faculties, supreme wisdom, and nirvana. … And what have I explained? Misery, the origin of misery, the cessation of misery, and the path leading to the cessation of misery. And why have I explained this? Because this does profit and concerns the fundamentals of religion … [Majjhima-Nikaya, 63]

No Self.

[Buddha:] In regard to the self, Ananda, what are the views held concerning it? One holds the view that (1) sensation is the self, saying, “sensation is my self,” or one holds the view that, (2) truly, sensation is not my self insofar as my self has no sensation. Or one holds the view that (3) truly, neither is sensation my self, nor does my self have no sensation; my self has sensation and my self possesses the faculty of sensation.

In the first case above where it is said, “sensation is my self,” one should reply as follows. Brother, there are three sensations, namely, the pleasant sensation, the unpleasant sensation, and the indifferent sensation. Which of these three sensations do you hold to be the self? Whenever a person experiences a pleasant sensation, he does not at the same time experience an unpleasant sensation, nor does he experience an indifferent sensation. At that time, he only feels the pleasant sensation. Whenever a person experiences an unpleasant sensation, he does not at the same time experience a pleasant sensation, nor does he experience an indifferent sensation. He only feels the unpleasant sensation. Whenever a person experiences an indifferent sensation, he does not at the same time experience a pleasant sensation, nor does he experience an unpleasant sensation. He only feels the indifferent sensation.

Now, pleasant sensations are transitory, are due to causes, originate by dependence, and are subject to decay, disappearance, effacement, and cessation. Unpleasant sensations are transitory, are due to causes, originate by dependence, and are subject to decay, disappearance, effacement, and cessation. Finally, indifferent sensations are transitory, due to causes, originate by dependence, and are subject to decay, disappearance, effacement, and cessation. While this person is experiencing a pleasant sensation, he thinks, “this is my self.” And after the cessation of this same pleasant sensation, he thinks, “my self has passed away.” While he is experiencing an unpleasant sensation, he thinks, “this is my self.” And after the cessation of this same unpleasant sensation, he thinks, “my self has passed away.” And while he is experiencing an indifferent sensation, he thinks, “this is my self.” And after the cessation of this same indifferent sensation, he thinks, “my self has passed away.” So that he who says, “sensation is my self,” holds the view that even during his lifetime his self is transitory, that it is pleasant, unpleasant, or mixed, and that it is subject to rise and disappearance.

[Buddha:] So, Ananda, it is not possible to hold the view that sensation is my self. In the second case above where it is said that truly sensation is not my self insofar as my self has no sensation, one should reply as follows. Brother, where there is no sensation, is there any “I am”?

[Ananda:] No, truly, Reverend Sir.

[Buddha:] So, Ananda, it is not possible to hold the view that, truly sensation is not my self insofar as my self has no sensation. In the third case above, one states that truly neither is sensation my self, nor does my self have no sensation. My self has sensation and my self possesses the faculty of sensation. One should reply to this as follows. Suppose, brother, all sensation were to cease, utterly, completely, and without remainder. If there were nowhere any sensation, would there be anything after the cessation of sensation of which you could say “this is me?”

[Ananda:] No, truly, Reverend Sir.

[Buddha:] So, Ananda, it is not possible to hold the view that truly neither is sensation my self, nor does my self have no sensation. My self has sensation and my self possesses the faculty of sensation.

[Buddha:] From the time a monk rejects the above three views (namely that sensation is the self, that the self has no sensation, and that the self has sensation insofar as it possesses the faculty of sensation) he ceases to attach himself to anything in the world, and is free from attachment. He is never agitated, and being never agitated, he attains nirvana in his own person. He knows that rebirth is all gone, that he has lived a holy life, that he has done what it obligated him to do, and that he is no more for this world. [Digha-nikaya 256, Mahanidana sutta]

Doctrine of Dependent Origin.

[Ananda:] Revered sir, how wonderful, marvelous and complex is dependent origin, and how complicated it appears to be. Nevertheless, to me it is as clear as clear can be.

[Buddha:] Don’t say that, Ananda, please don’t say that. Dependent origin appears complicated and is complex. It is through not understanding and penetrating this doctrine that humankind is accordingly like an entangled twist, an ensnared web, or like jumbled munja grass and pabbaja grass. It fails to disengage itself from punishment, suffering, destruction, and rebirth. If one asks whether old age and death depend on anything, the reply should be that old age and death depend on birth. If one asks whether birth depends on anything, the reply should be that birth depends on existence. If one asks whether existence depends on anything, the reply should be that existence depends on attachment. If one asks whether attachment depends on anything, the reply should be that attachment depends on desire. If one asks whether desire depends on anything, the reply should be that desire depends on sensation. If one asks whether sensation depends on anything, the reply should be that sensation depends on contact. If one asks whether contact depends on anything, the reply should be that contact depends on mental and physical phenomena. If one asks whether mental and physical phenomena depend on anything, the reply should be that they depend on consciousness. If one asks whether consciousness depends on anything, the reply should be that consciousness depends on mental and physical phenomena.

Thus, consciousness depends on mental and physical phenomena; mental and physical phenomena depend on consciousness; contact depends on mental and physical phenomena; sensation depends on contact; desire depends on sensation; attachment depends on desire; existence depends on attachment; birth depends on existence; old age, death, sorrow, lamentation, misery, grief and despair all depend on birth. This is how the entire aggregate of misery arises. [Digha-nikaya 256, Mahanidana sutta]


The venerable Bodhisattva Avalokitesvara was studying in the deep Perfection of Wisdom. He reflected that there are the five components (skandhas) [of our phenomenal nature], and he considered these to be empty by their nature. [Speaking to Sariputra,] he said, “Oh Sariputra, form here is emptiness and emptiness is indeed form. Emptiness is not different from form, and form is not different from emptiness. Whatever is form is emptiness, and whatever is emptiness is form. The same applies to perception, name, conception and knowledge. Here, Sariputra, all things have the character of emptiness. They have no beginning, no end, they are faultless and not faultless, they are perfect and they are imperfect. Therefore, Sariputra, there is no form in this emptiness, no perception, no name, no concepts, no knowledge. There is no eye, ear, nose, tongue, body, or mind. There is no form, sound, smell, taste, touch, or objects. There is no eye, ear, nose, tongue, body, and mind, no objects, no mind-knowledge.

There is no knowledge, no ignorance, or no destruction of knowledge. There is no decay and death, or no destruction of decay and death. There are no [four noble truths, namely,] that there is pain, the origin of pain, the elimination of pain, and the path to it. There is no knowledge, no obtaining, no not obtain of nirvana. Therefore, Sariputra, as there is no obtaining of nirvana, a man who has approached the Perfection of Wisdom of the Bodhisattvas dwells for a time enveloped in consciousness. But when the envelopment of consciousness has been annihilated, then he becomes free of all fear, beyond the reach of change, enjoying final nirvana.

All Buddhas of the past, present, and future, after approaching the Perfection of Wisdom, have awaken to the highest perfect knowledge. Therefore we ought to know the great verse of the Perfection of Wisdom. It is the verse of the great wisdom, the unsurpassed verse, the verse that appeases all pain. It is truth, not falsehood. It is the verse fit for obtaining the Perfection of Wisdom: ‘Oh wisdom gone; gone, gone to the other shore, landed at the other shore; it is offered (svaha)!’ In this way, Sariputra, should a Bodhisattva teach in the study of the deep Perfection of Wisdom.” [Heart Sutra]

If everything is relative, and there is no [real] origination and no [real] annihilation, how, then is nirvana conceived? Through what deliverance and through what annihilation [would this take place]? If everything is real in substance, and there is no [new] creation and no [new] destruction, how, then, would nirvana be reached? Through what deliverance and through what annihilation [would this take place]? [Nirvana is] what is neither released, nor ever reached; what is neither annihilated nor is eternal; what neither disappears nor has been created. This is nirvana. It escapes precision. … There is no difference at all between nirvana and the realm of life/death (samsara). There is no difference at all between the realm of life/death and nirvana. What makes the limit of nirvana is also then the limit of the realm of life/death. Between the two we cannot find the slightest shade of difference. [Nagarjuna, Treatise, Ch. 25]


Philosophy within Confucian religion beginning around 500 BCE that emphasizes the moral virtues and governmental rule through moral example.

Ritual Conduct

7:17. The Master’s frequent themes of discourse were-the Odes, the History, and the maintenance of the rules of social custom. On all these he frequently discoursed.

8:2. The Master said, “Respectfulness without the rules of social custom becomes laborious bustle. Carefulness without the rules of social custom becomes timidity. Boldness without the rules of social custom becomes insubordination. Straightforwardness without the rules of social custom becomes rudeness. When those who are in high stations properly perform all their duties to their relations, the people are inspired towards virtue. When old friends are not neglected by them, the people are preserved from meanness.”

8.8. The Master said, “It is by the Odes that the mind is aroused. It is by the rules of social custom that the character is established. It is from Music that the finish is received.”

12:1 Yen Yuan asked about perfect virtue. The Master said, “To subdue one’s self and return to social custom is perfect virtue. If a person can for one day subdue himself and return to social custom, all under heaven will attribute perfect virtue to him. Is the practice of perfect virtue from a person himself, or is it from others?” Yen Yuan said, “I beg to ask the steps of that process.” The Master replied, “Do not look at what is contrary to social custom; do not listen to what is contrary to social custom; do not speak what is contrary to social custom; do not make movements which are contrary to social custom.” Yen Yuan then said, “Though I am deficient in intelligence and vigor, I will make it my business to practice this lesson.”

16:13. Another day he was in the same way standing alone, when I passed by below the hall with hasty steps. He said to me, “Have you learned the rules of social custom?” On my replying “Not yet,” he added, “If you do not learn the rules of social custom, your character cannot be established.” I then retired, and learned the rules of social custom. [Analects]


1:3. The Master said, “Fine words and an insinuating appearance are seldom associated with true humanity.”

4:1-4. The Master said, “It is humane manners that constitute the excellence of a neighborhood. If a person in selecting a residence does not fix on one where such prevail, how can he be wise?” The Master said, “Those who are without humanity cannot abide long either in a condition of poverty and hardship, or in a condition of enjoyment. The virtuous rest in humanity; the wise desire humanity.” The Master said, “It is only the truly humane person who can love, or who can hate, others.” The Master said, “If one’s will is set on humanity, there will be no practice of wickedness.”

4:6-7. The Master said, “I have not seen a person who really loved humane attitudes, or one who really hated inhumane attitudes. One who loved humanity would value nothing above it. One who hated inhumanity would practice virtue in such a way that he would not allow anything that is not humane to approach his person. Is anyone able to apply his strength to humanity for even a single day? I have not seen the case in which his strength would be insufficient to do so. Should there possibly be any such case, I have not seen it.” The Master said, “The faults of people are characteristic of the class to which they belong. By observing a person’s faults, it may be known that he is virtuous.”

5:11. Tzu-kung said, “What I do not wish people to do to me, I also wish not to do to people.” The Master said, “Ts’ze, you have not attained to that.”

12:1-2. Chung-kung asked about perfect virtue. The Master said, “It is, when you go abroad, to behave to everyone as if you were receiving a great guest; to employ the people as if you were assisting at a great sacrifice; not to do to others as you would not wish done to yourself; to have no murmuring against you in the country, and none in the family.” Chung-kung said, “Though I am deficient in intelligence and vigor, I will make it my business to practice this lesson.” Sze-ma Niu asked about perfect virtue. The Master said, “The person of perfect virtue is cautious and slow in his speech.”

15:23. Tzu-kung asked, saying, “Is there one word that may serve as a rule of practice for all one’s life?” The Master said, “Is not reciprocity such a word? What you do not want done to yourself, do not do to others.” [Analects]

Superior Person

2.9. The Master said, “The superior person is universal and not partisan. The inferior person is partisan and not universal.”

4.10. The Master said, “The superior person in the world does not set his mind either for anything, or against anything. What is right he will follow.”

4.11. The Master said, “The superior person thinks of virtue; the small person thinks of comfort. The superior person thinks of the sanctions of law; the small person thinks of favors which he may receive.”

4.24. The Master said, “The superior person wishes to be slow in his speech and earnest in his conduct.”

5.15. The Master said of Tzu-ch’an that he had four of the characteristics of a superior person: in his conduct of himself, he was humble; in serving his superior, he was respectful; in nourishing the people, he was kind; in ordering the people, he was just.”

15:17-22. The Master said, “The superior person in everything considers righteousness to be essential. He performs it according to the rules of social custom. He brings it forth in humility. He completes it with sincerity. This is indeed a superior person.” The Master said, “The superior person is distressed by his want of ability. He is not distressed by people not knowing him.” The Master said, “The superior person dislikes the thought of his name not being mentioned after his death.” The Master said, “What the superior person seeks is in himself. What the inferior person seeks is in others.” The Master said, “The superior person is dignified, but does not wrangle. He is sociable, but not a partisan.” The Master said, “The superior person does not promote someone simply on account of his words, nor does he put aside good words because of the person.”

7.32.The Master said, “The sage and the person of perfect virtue; how dare I rank myself with them? It may simply be said of me, that I strive to become such without being filled, and teach others without weariness.” Kung-hsi Hwa said, “This is just what we, the disciples, cannot imitate you in.”

7:33. The Master said, “In letters I am perhaps equal to other people, but the character of the superior person, carrying out in his conduct what he professes, is what I have not yet attained to.”

7:36. The Master said, “The superior person is satisfied and composed; the inferior person is always full of distress.”

11:4-5. Sze-ma Niu asked about the superior person. The Master said, “The superior person has neither anxiety nor fear.” Nui said, “Being without anxiety or fear! Does this constitute what we call the superior person?” The Master said, “When internal examination discovers nothing wrong, what is there to be anxious about? What is there to fear?” Sze-ma Niu anxiously replied, “Other people all have their brothers, I’m the only one who doesn’t.” Confucius said to him, “There is a saying which I have heard: ‘Death and life have their determined appointment; riches and honors depend upon Heaven.’ Let the superior person never fail in reverence to order his own conduct, and let him be respectful to others and observant of social custom. Then everyone within the four seas will be his brothers. What has the superior person to do with being distressed because he has no brothers?” [Analects]

Filial Obedience

1.2. The philosopher Yu [i.e., Confucius’s pupil] said, “Few people who are filial and fraternal are also fond of offending superiors. No one who is respectful to superiors is fond of stirring up confusion. The superior person bends his attention to what is fundamental. When that root is established, moral law (Dao) naturally grow. Filial obedience and fraternal submission, are the root of all humane action (jen).

1:6. The Master said, “When at home, a youth should be filial [to his parents], and when abroad he should be respectful to his elders. He should be earnest and truthful. He should overflow in love to all, and cultivate the friendship good people. When he has time and opportunity, after the performance of these things, he should study art and literature (wen).”

2.7. Tzu-yu asked what filial obedience was. The Master said, “Filial obedience nowadays means to support one’s parents. But dogs and horses also are able to do something in the way of support. Without reverence, what is there to distinguish the one support given from the other?”

4.10. The Master said, “If the son for three years does not alter from the way of his father, he may be called filial.”

2.5. Meng-I-tzu asked what filial obedience was. The Master said, “It is not being disobedient.” Soon after, as Fan Ch’ih was driving him, the Master told him, “Meng-sun asked me what filial obedience was, and I answered him, ‘not being disobedient.'” Fan Ch’ih said, “What did you mean?” The Master replied, “That parents, when alive, be served according to social custom; that, when dead, they should be buried according to social custom; and that they should be sacrificed to according to social custom.” [Analects]

Good Government

2:1. The Master said, “He who exercises government by means of his virtue may be compared to the north polar star, which keeps its place and all the stars turn towards it.”

2:3. The Master said, “If the people are led by laws, and uniformity imposed through punishments, then they will try to avoid the punishment, but have no sense of shame. If they are led by virtue, and uniformity imposed through the rules of social custom, then they will have the sense of shame, and moreover will become good.”

13:16. The Duke of Sheh asked about government. The Master said, “Good government obtains when those who are near are made happy, and those who are far off are attracted to come.”

13:17. Tzu-hsia, being governor of Chu-fu, asked about government. The Master said, “Do not desire to have things done quickly and do not look at small advantages. If you desire to have things done quickly, this prevents them being done thoroughly. If you look at small advantages, this prevents great affairs from being accomplished.”

16.2. Confucius said, “When good government prevails in the empire, ceremonies, music, and military expeditions proceed from the son of Heaven. When bad government prevails in the empire, ceremonies, music, and military expeditions proceed from the princes. …”

20.2. Tzu-chang asked Confucius, saying, “In what way should a person in authority act in order that he may conduct government properly?” The Master replied, “Let him honor the five excellent things, and banish away the four bad, things; then may he conduct government properly.” Tzu-chang said, “What are meant by the five excellent things?” The Master said, “When the person in authority is beneficent without great expense; when he lays tasks on the people without their grieving; when he pursues what he desires without being selfish; when he maintains a dignified ease without being proud; when he is majestic without being cruel.”

Tzu-chang said, “What is meant by being beneficent without great expenditure?” The Master replied, “When the person in authority makes those things more beneficial to the people from which they naturally derive benefit; is not this being beneficent without great expense? When he chooses the labors which are proper, and makes them labor on them, who will grieve? When his desires are set on benevolent government, and he secures it, who will accuse him of greed? Whether he has to do with many people or few, or with things great or small, he does not dare to indicate any disrespect. Isn’t this maintaining a dignified ease without any pride? He adjusts his clothes and cap, and throws a dignity into his looks, so that, thus dignified, he is looked at with awe. Isn’t this being majestic without being fierce?”

Tzu-chang then asked, “What is meant by the four bad things?” The Master said, “To put the people to death without having instructed them; this is called cruelty. To suddenly require from them a full load of work, without having given them warning; this is called oppression. To issue orders as if without urgency, at first, and, when the time comes, to insist on them with severity; this is called injury. And, generally, in the giving pay or rewards to people, to do it in a stingy way; this is called acting the part of a mere official.” [Analects]


[Kao:] Human nature is like a tree, and righteousness (i) is like a wooden cup or a bowl. The fashioning of benevolence and righteousness out of a person’s nature is like the making of cups and bowls from the tree.

[Mencius:] Without touching the nature of the tree, can you make it into cups and bowls? You must do violence and injury to the tree before you can make cups and bowls with it. If you must do violence and injury to the tree in order to make cups and bowls with it, on your principles you must in the same way do violence and injury to humanity in order to fashion from it benevolence and righteousness. Thus, your words would certainly lead all people on to consider benevolence and righteousness to be calamities.

[Kao:] Human nature is like water whirling around in a corner. Open a passage for it to the east, and it will flow to the east. Open a passage for it to the west, and it will flow to the west. Human nature is indifferent to good and evil, just as water is indifferent to the east and west.

[Mencius:] Water indeed will flow indifferently to the east or west, but will it flow indifferently up or down? The tendency of human nature to do good is like the tendency of water to flow downwards. All people have this tendency to good, just as all water flows downwards. Now, by striking water and causing it to leap up, you may make it go over your forehead, and, by damming and leading it, you may force it up a hill. But are such movements according to the nature of water? It is the force applied which causes them. When people are made to do what is not good, their nature is dealt with in this way. [Mencius, 6a1, 2]


Philosophy within China’s Daoist religion beginning around 400 BCE that emphasizes the pantheistic notion of the Dao as the fundamental ordering principle behind nature, society, and individual people

The Dao

  1. The Dao that can be named is not the eternal and unchanging Dao. The name that can be spoken is not the eternal and unchanging name. The nameless is the source of heaven and earth. The named is the mother of all things. Always be without desires and you will see mystery. Always be with desire, and you will see only its effects. These two are really the same, although, as development takes place, they receives the different names. They are both a mystery, and where mystery is the deepest we find the gate of all that is subtle and wonderful.
  2. The Dao is like the emptiness of a vessel; and in our employment of it we must be on our guard against all fullness. How deep and unfathomable it is, as if it were the honored ancestor of all things. We should blunt our sharp points, and unravel the complications of things; we should dim our brightness, and bring ourselves into agreement with the obscurity of others. How pure and still the Dao is, as if it would continue forever. I do not know whose son it is. It might appear to have been before God.

10 … The Dao produces all things and nourishes them; it produces them and does not claim them as its own; it does all, and yet does not boast of it; it presides over all, and yet does not control them. This is what is called “the mysterious quality” of the Dao.

  1. We look at it, and we do not see it, and we name it “the Equable.” We listen to it, and we do not hear it, and we name it “the Inaudible.” We try to grasp it, and do not get hold of it, and we name it “the Subtle.” With these three qualities, it cannot be made the subject of description; and hence we blend them together and obtain The One. Its upper part is not bright, and its lower part is not obscure. Ceaseless in its action, it yet cannot be named, and then it again returns and becomes nothing. This is called the Form of the Formless, and the Appearance of the Invisible; this is called the Fleeting and Indeterminable. We meet it and do not see its front; we follow it, and do not see its back. When we can lay hold of the Dao of old to direct the things of the present day, and are able to know it as it was of old in the beginning, this is called unwinding the clue of Dao.
  2. When the Great Dao ceased to be observed, benevolence and righteousness came into fashion. Then appeared wisdom and shrewdness, and there arose great hypocrisy. When harmony no longer prevailed throughout the six kinships, filial sons found their manifestation; when the states and clans fell into disorder, loyal ministers appeared.
  3. There was something undefined and complete, coming into existence before Heaven and Earth. How still and formless it was, standing alone, and undergoing no change, reaching everywhere and in no danger of being exhausted. It may be regarded as the Mother of all things. I do not know its name, and I give it the designation of the Dao, the Way or Course. Making an effort further to give it a name I call it “the Great.” Great, it passes on in constant flow. Passing on, it becomes remote. Having become remote, it returns. Therefore the Dao is great; Heaven is great; Earth is great; and the sage king is also great. In the universe there are four that are great, and the sage king is one of them. People take their law from the Earth; the Earth takes its law from Heaven; Heaven takes its law from the Dao. The law of the Dao is its being what it is.
  4. The Dao, considered as unchanging, has no name. Though in its primordial simplicity it may be small, the whole world dares not deal with one embodying it as a government minister. If a feudal prince or the king could guard and hold it, all would spontaneously submit themselves to him. Heaven and Earth under its guidance unite together and send down the sweet dew, which, without the directions of people, reaches equally everywhere as of its own accord. As soon as it moves on to action, it has a name. When it once has that name, people can know to rest in it. When they know to rest in it, they can be free from all risk of failure and error. The relation of the Dao to all the world is like that of the great rivers and seas to the streams from the valleys. [Dao De Jing]


  1. The state of vacancy should be brought to the utmost degree, and that of stillness guarded with unwearying vigor. All things alike go through their processes of activity, and then we see them return to their original state. When things in the vegetable world have displayed their luxuriant growth, we see each of them return to its root. This returning to their root is what we call the state of stillness; and that stillness may be called a reporting that they have fulfilled their appointed end.
  2. When the government is unwise, the people are good. When the government is alert, the people meddle with everything. Happiness rests on misery, misery lurks beneath happiness. Who knows what either will come to in the end? Should we give up on correcting things? The method of correction will in turn become a distortion, and the good in it will in turn become evil. The delusion of the people on this point has indeed subsisted for a long time. [Dao De Jing]


  1. The softest thing in the world dashes against and overcomes the hardest; that which has no substantial existence enters where there is no crevice. I know by this what advantage there is to doing nothing with a purpose. There are few in the world who attain to the teaching without words, and the advantage arising from non-action.
  2. A state may be ruled by measures of correction; weapons of war may be used with crafty dexterity; but the kingdom is made one’s own only by freedom from action and purpose. How do I know that it is so? By these facts: growth of restrictive laws in kingdoms increases the poverty of the people; the more devices that the people have to add to their profit, the greater disorder there is in the state and clan; the more acts of crafty dexterity that people possess, the more do strange contrivances appear; the more display there is of legislation, the more thieves and robbers there are. Therefore a sage has said, “I will do nothing with purpose, and the people will transform themselves; I will keep still, and the people will correct themselves. I will not trouble with them, and the people will become rich by themselves; I will show no ambition, and the people will arrive at primitive simplicity by themselves.”
  3. It is the way of the Dao to act without thinking of acting; to conduct affairs without feeling the trouble of them; to taste without discerning any flavor; to consider what is small as great, and a few as many; and to recompense injury with kindness. …
  4. Man at his birth is supple and weak; at his death, firm and strong. So it is with all things. In their early growth, trees and plants are soft and brittle; at their death they are dry and withered. In this manner, firmness and strength are the accompaniments of death, whereas softness and weakness are the accompaniments of life. Hence the person who relies on the strength of his forces does not conquer; and a tree that is strong will fill out-stretched arms, and thereby invites the lumberjack. Therefore the place of what is firm and strong is below, and that of what is soft and weak is above.
  5. There is nothing in the world more soft and weak than water, and yet for attacking things that are firm and strong there is nothing that can outrank it. For, there is nothing so effective for which it can be changed. Everyone in the world knows that the soft overcomes the hard, and the weak overcomes the strong, but no one is able to carry it out in practice. Therefore a sage said, “Those who accept the humiliation of the state are worthy of offering sacrifices. Those who accept the state’s woes are worthy of ruling an empire.” Words that are strictly true seem to be paradoxical. [Dao De Jing]


  1. Without going outside his door, one understands all that takes place under the sky; without looking out from his window, one sees the Dao of Heaven. The further that one goes out from himself, the less he knows. Therefore the sages got their knowledge without traveling, gave their right names to things without seeing them, and accomplished their ends without any purpose of doing so.
  2. He who devotes himself to learning seeks from day to day to increase his knowledge. He who devotes himself to the Dao seeks from day to day to diminish his doing. He diminishes it and again diminishes it, until he arrives at doing nothing on purpose. Having arrived at this point of non-action, there is nothing that he does not do. He who gets as his own all under heaven does so by giving himself no trouble with that end. If one take trouble with that end, he is not equal to getting as his own all under heaven.
  3. Sincere words are not fine, and fine words are not sincere. Those who are skilled in the Dao do not dispute about it, and those who dispute are not skilled in it. Those who know the Dao are not extensively learned, and the extensively learned do not know it. The sage does not accumulate for himself. The more that he expends for others, the more does he possess of his own. The more that he gives to others, the more does he have himself. With all the sharpness of the Way of Heaven, it injures not; with all the doing in the way of the sage he does not strive.
  4. Not to value and employ people of superior ability is the way to keep the people from rivalry among themselves. Not to prize articles which are difficult to procure is the way to keep them from becoming thieves. Not to show them what is likely to excite their desires is the way to keep their minds from disorder. Therefore, in exercising his government, the sage empties the people’s minds, fills their bellies, weaken their wills, and strengthen their bones. He constantly tries to keep them without knowledge and without desire, and where there are those who have knowledge, to keep them from acting on it. When there is this abstinence from action, good order is universal. [Dao De Jing]

Story of the Cook

Prince Hui’s cook was cutting up a bull. Every blow of his hand, every heave of his shoulders, every tread of his foot, every thrust of his knee, every whshh of cut flesh, every chhk of the knife, was in perfect harmony, rhythmical like the dance of the Mulberry Grove, simultaneous like the chords of the Ching Shou.

The prince said, “Ah! It is indeed admirable that your art has become so perfect!”

[Having finished his task], the cook laid down his knife, and replied to the remark. “I am devoted to the method of the Dao, which is superior to any skill. When I first began to cut up bulls, I saw nothing but the [entire] carcass. After three years I ceased to see it as a whole. Now I deal with it in a spirit-like manner, and do not look at it with my eyes. I discarded the use of my senses, and my spirit acts as it wills. Observing the natural lines, [my knife] slips through the great crevices and slides through the great cavities, taking advantage of the accommodations thus presented. My skill avoids the ligaments, and much more the large bones.

A good cook changes his knife every year because he cleanly cuts. An ordinary cook changes his every month because he hacks. Now I have used my knife for nineteen years. It has cut up several thousand bulls, and yet its edge is as sharp as if it came right from the whetstone. There are crevices in the joints, and the edge of the knife has no appreciable thickness. When that which is so thin enters the crevice, how easily it moves along! The blade has more than enough room. However, whenever I come to a complicated joint and see that there will be some difficulty, I proceed with caution. I do not allow my eyes to wander from the place, and move my hand slowly. Then by a very slight movement of the knife, the part is quickly separated, and drops like a clod of earth to the ground. Then standing up with the knife in my hand, I leisurely look all round, and with an air of satisfaction, wipe it clean, and put it in its sheath.”

“Excellent!” said the Prince. “I have heard the words of my cook, and learned how to care for life.” [Chuang-Tzu, 3]

Transformation and the Story of the Dying Man

Masters Ssu, Yu, Li, and Lai were all four conversing together. They asked, “Who can make non-action his head, life his backbone, and death the tail of his existence? Who knows how birth and death, existence and annihilation comprise one single body? The person who understands this will be admitted to friendship with us.” The four men looked at one another and laughed, but no one seized with his mind the drift of the questions. All, however, were friends together.

Not long after, Yu fell ill, and Ssu went to see him. “How great is the Creator!” said the sufferer. “He made me the deformed object that I am!” Yu was a crooked hunchback; his five viscera were squeezed into the upper part of his body; his chin bent over his navel; his shoulder was higher than his crown; on his crown was an ulcer pointing to the sky; his breath came and went in gasps. Nevertheless, he was easy in his mind, and made no trouble of his condition. He limped to a well, looked at himself in it, and said, “I can’t believe that the Creator would have made me the deformed object that I am!” Ssu said, “Do you dislike your condition?” He replied, “No, why should I dislike it? If the creator transformed my left arm into a rooster, I would watch the time of the night. If he transformed my right arm into a cross-bow, I would then be looking for a duck to shoot for roasting. If he transformed my rump-bone into a wheel and my spirit into a horse, I would then be able to ride in my own chariot. I’d never have to change horses. I obtained life because it was my time. I am now parting with it in accordance with the same law. When we rest in what the time requires, and manifest that submission, neither joy nor sorrow can enter. This is what the ancients called ‘loosening the rope.’ Some, though, are hung up and cannot loosen themselves. They are held fast by the bonds of material existence. But it is a long-acknowledged fact that no creatures can overcome Heaven. Why, then, should I hate my condition?” [Chuang-Tzu, 6]

Freedom from Society’s Constraints.

With their hoofs horses can tread on ice and snow, and with their hair withstand the wind and cold; they feed on the grass and drink water; they prance with their legs and leap. This is the true nature of horses. Even if grand towers and large dormitories were made for them, they would prefer not to use them. One day Poh Loh [i.e., the original mythical tamer of horses] said, “I know well how to manage horses.” Accordingly, he clipped them, pared their hoofs, haltered their heads, bridled them and shackled their legs, and confined them in stables and corrals. [With this treatment] two or three in every ten of them died. Still, he subjected them to hunger and thirst; he galloped them and raced them, and made them prance in regular order. In front of the horses were the evils of the bit and ornamented breast bands, and behind were the terrors of the whip and switch. With this treatment more than half of them died. . . .

According to my idea, those who know how to properly govern humankind would not act so. People had their regular and constant nature. They originally wove and made themselves clothes; they tilled the ground for food. These are common to humanity. They all agreed on this, and did not form themselves into separate classes. In this way they were constituted and left to their natural tendencies. Therefore in the age of perfect virtue people walked along quietly, steadily looking forward. At that time, on the hills there were no footpaths or excavated passages. On the lakes there were no boats or dams. All creatures lived in groups, and the places of their settlement were made close to one another. Birds and beasts multiplied to flocks and herds. The grass and trees grew luxuriant and long. In this condition the birds and beasts could be led about without feeling the constrained. One could climb up to the nest of the raven and peep into it. Yes, in the age of perfect virtue, people lived in common with birds and beasts, and were on equal terms with all creatures, forming one family. How could they have distinctions between superior and inferior people? As they were all without knowledge, they did not leave their condition of natural virtue. Equally free from evil desires, they were in the state of natural integrity. In that state of natural integrity, the nature of the people was what it ought to be.

But when sages appeared, tripping people up with charity and constraining people with the duty to one’s neighbor, then people universally began to be perplexed. The sages went to excess in performing music and fussed over the practice of ceremonies. Then people began to be separated from each other. If raw materials were not cut and hacked, who could have made a sacrificial vase from them? If natural jade was not broken, who could have made the handles for the ceremonial drinking cups? If the Dao was not abandoned, who could have introduced charity and duty to one’s neighbor? If they did not depart from natural instincts, how could ceremonies and music have come into use? If the five colors were not confused, who would practice decoration? If the five notes were not confused, who would adopt the six pitched-pipes? The cutting and hacking of the raw materials to form vessels was the crime of the artisans. The injury done to the Dao in order to practice charity and duty to one’s neighbor was the error of the sages. [Chuang-Tzu, 9]


The longest life span is 100 years, although not even one person in a thousand lives that long. Even if there is someone who lives out his span, infancy and incapacitating old age consume almost half of it. Sleeping at night and wasted days consume nearly half of what remains. Suffering and illness, sadness and drudgery, loss of loved ones, distress and fear consume almost half of that. During the remaining ten or so years, I suppose that there is less than an hour during which time we are comfortable, satisfied and carefree.

What, then, are we to live for? Where do we find happiness? It is only found in beautiful things and good food, music and sex. However, we cannot always have beautiful things and good food. We are not always in a position to enjoy music and sex. Further, we are inhibited by punishments and motivated by rewards. We are urge on by fame and restrained by the law. We busily compete for a moment of empty praise and strategize for fame that will last beyond our deaths. Even when we are alone we conform to what others do and say, and deny our own preferences. We thus deny ourselves happiness in our best years, and we cannot live freely for a moment. Are we any different than prisoners bound in chains and bondage?

People of long ago understood that in life we are here temporarily and in death we are gone temporarily. Accordingly they behaved as they pleased and they did not resist their natural desires. … Some of die in ten years, and others in a hundred. Saints and sages both die. The wicked and foolish both die. While alive they were the virtuous emperors Yao and Shun. When dead they are rotten bones. While alive they were the evil emperors Chieh and Chou. When dead they are rotten bones. In either case, they are rotten bones. Can anyone tell them apart? Enjoy your life right now while you still have it. Why bother with what happens to you after you die? [Lieh-Tzu, 7]


Early medieval Christian philosopher, influenced by Neoplatonism, who emphasized attaining knowledge through divine illumination and achieving moral goodness by supremely loving God only.

Knowledge Skepticism

I do not know how the Academician can refute him who says “I know that this appears white to me, I know that my hearing is delighted with this, I know that this has an agreeable odor, I know that this tastes sweet to me, I know that this feels cold to me.”

I have learned through dialectic that many other things are true. Count, if you can, how many there are: If there are four elements in the world, there are not five; if there is one sun, there are not two; one and the same soul cannot die and still be immortal; man cannot at the same time be happy and unhappy; if the sun is shining here, it cannot be night; we are now either awake or asleep; either there is a body which I seem to see or there is not a body. [Against the Academics, 3:11 and 13]

Without any delusive representation of images or phantasms, I am most certain that I am, and that I know and delight in this. In respect of these truths, I am not at all afraid of the arguments of the Academicians, who say, What if you are deceived? For if I am deceived, I am. For he who is not, cannot be deceived; and if I am deceived, by this same token I am. And since I am if I am deceived, how am I deceived in believing that I am? for it is certain that I am if I am deceived. Since, therefore, I, the person deceived, should be, even if I were deceived, certainly I am not deceived in this knowledge that I am. And, consequently, neither am I deceived in knowing that I know. For, as I know that I am, so I know this also, that I know. [City of God, 11:26]

The Academic philosophy has so succeeded as to be still more wretchedly insane by doubting all things;—passing by, then, those things that come into the mind by the bodily senses, how large a proportion is left of things which we know in such manner as we know that we live? In regard to this, indeed, we are absolutely without any fear lest perchance we are being deceived by some resemblance of the truth; since it is certain, that he who is deceived, yet lives. And this again is not reckoned among those objects of sight that are presented from without, so that the eye may be deceived in it; in such way as it is when an oar in the water looks bent, and towers seem to move as you sail past them, and a thousand other things that are otherwise than they seem to be: for this is not a thing that is discerned by the eye of the flesh.

The knowledge by which we know that we live is the most inward of all knowledge, of which even the Academic cannot insinuate: Perhaps you are asleep, and do not know it, and you see things in your sleep. For who does not know that what people see in dreams is precisely like what they see when awake? But he who is certain of the knowledge of his own life, does not therein say, I know I am awake, but, I know I am alive; therefore, whether he be asleep or awake, he is alive. Nor can he be deceived in that knowledge by dreams; since it belongs to a living man both to sleep and to see in sleep. Nor can the Academic again say, in confutation of this knowledge: “Perhaps you are mad, and do not know it: for what madmen see is precisely like what they also see who are sane” But he who is mad is alive. Nor does he answer the Academic by saying, “I know I am not mad,” but instead, “I know I am alive.” Therefore he who says he knows he is alive, can neither be deceived nor lie. Let a thousand kinds, then, of deceitful objects of sight be presented to him who says, I know I am alive; yet he will fear none of them, for he who is deceived yet is alive. . .

For whereas there are two kinds of knowable things,—one, of those things which the mind perceives by the bodily senses; the other, of those which it perceives by itself,—these philosophers have babbled much against the bodily senses, but have never been able to throw doubt upon those most certain perceptions of things true, which the mind knows by itself, such as is that which I have mentioned, I know that I am alive. But far be it from us to doubt the truth of what we have learned by the bodily senses; since by them we have learned to know the heaven and the earth, and those things in them which are known to us, so far as He who created both us and them has willed them to be within our knowledge. Far be it from us too to deny, that we know what we have learned by the testimony of others: otherwise we know not that there is an ocean; we know not that the lands and cities exist which most copious report commends to us; we know not that those men were, and their works, which we have learned by reading history; we know not the news that is daily brought us from this quarter or that, and confirmed by consistent and conspiring evidence; lastly, we know not at what place or from whom we have been born: since in all these things we have believed the testimony of others. And if it is most absurd to say this, then we must confess, that not only our own senses, but those of other persons also, have added very much indeed to our knowledge. [On the Trinity, 15]

Divine Illumination

There are the three kinds of vision about which we had something to say. . . . Let us call the first kind of vision corporeal, because it is perceived through the body and presented to the senses of the body. The second will be spiritual, called spirit; and certainly the image of an absent body through it resembles a body, is not itself a body any more than is the act of vision by which it is perceived. The third kind will be intellectual, from the word “intellect”. . . .

Among the objects of the intellect, there are some that are seen in the soul itself, for example, virtues which will endure, such as piety, or virtues that are useful for this live and not destined to remain in the next, as faith. . . . And yet even they area seen with the intellect; for they are not bodies, nor have they forms similar to bodies. But distinct from these objects is the light by which the soul is illuminated, in order that it may see and truly understand everything, either in itself is in the light. For the light is God himself, whereas the soul is a creature; yet, since it is rational and intellectual, it is made in his image. And when it tries to behold the light, it trembles in its weakness and finds itself unable to do so. Yet from this source comes all the understanding it is able to attain. When, therefore, it is thus carried off and, after being withdrawn from the senses of the body, is made present to this vision in a more perfect manner (not by a spatial relation, but in a way proper to its being), it also sees above itself that light in whose illumination it is enabled to see al the objects that it sees and understands in itself. [Commentary on Genesis, 6:15, 31:59]


These two times then, past and future, how can they exist since the past is gone and the future is not yet here? But if the present stayed present, and never passed into time past, then, truly, it would not be time, but eternity. Suppose that time present (if it is to be time) only comes into existence because it passes into time-past. How, then, can we say that it exists, since its existence is caused by the fact that it will not exist? We can’t truly say that time is, then, except because it tends towards non-being. . . .

Even if I don’t, I at least know that, wherever they are, they are not in the future or past, but in the present. For if they are there in the future, then they are not yet there, and if they are there in the past, then they are not there still. Wherever they are and whatever they are, they exist only as present. When past facts are related, they are drawn out of the memory – not the events themselves which are past, but the words. These words are conceived by the images of the passing events which, through the senses, left traces in the mind. . . . When the future is seen, we do not see the events themselves since these as yet do not exist. Instead, we see their causes or signs which already exist. Therefore they are not future but present to those who now see and foretell the future events as fore-conceived in the mind. Again, such fore-conceptions exist now, and those who foretell those things hold present conceptions. . . .

It is now plain and evident that neither future nor past things exist. Nor can we properly say, “there are three times: past, present, and future”. Instead, it we might properly say “there are three times: a present-of-things-past, a present-of-things-present, and a present-of-things-future.” For these three do exist in the mind in some way, but any other way I cannot see them. The present-of-things-past involves memory, the present-of-things-present involves perception, and the present-of-things-future involves expectation. If I am permitted to speak, I see and confess that there are three times. I also say that there are three times, past, present, and future, according to our misapplied custom. However, I will not object or find fault with this custom as long as it is understood neither the future or past exist. We speak properly of few things, and improperly of most things, although we understand what we mean. [Confessions 11:14, 18, 20]

Morality and Properly Ordered Love

Beauty, which is indeed God’s handiwork, but only a temporal, carnal, and lower kind of good, is not fitly loved in preference to God, the eternal, spiritual, and unchangeable good. When the miser prefers his gold to justice, it is through no fault of the gold, but of the man; and so with every created thing. For though it be good, it may be loved with an evil as well as with a good love: it is loved rightly when it is loved with proper order; evilly, when disordered. . . . But if the Creator is truly loved (that is, if he himself is loved and not another thing in his stead), he cannot be evilly loved. For love itself is to be properly ordered loved, because we do well to love that which, when we love it, makes us live well and virtuously. So that it seems to me that it is a brief but true definition of virtue to say, it is the order of love. [City of God, 15:22]

There are two kinds of things, eternal and temporal. Also, there are two kinds of people have been clearly and sufficiently distinguished: those who pursue and love eternal things, and those who pursue and love temporal things. We have established, moreover, that what each person chooses to pursue and to love lies in his own will, and that the mind cannot be disposed from the fortress of power or from right order by anything except the will. And it is clear that things themselves are not to be blamed when someone makes evil use of them; rather, the person who makes evil use of them is to be blamed. [On Free Choice, 1.16]

Problem of Evil

[You ask whether God is the cause of evil. In response,] if you know or believe that God is good (and it is not right to believe otherwise) then he does no evil. Further, if we recognize that God is just (and it is impious to deny it) then he rewards the good and punishes the wicked. Such punishments are indeed evils for those who suffer them. Therefore, if no one is punished unjustly (this we must believe since we believe that this universe is governed by divine providence) it follows that God is a cause of the suffering of some evil, but in no way causes the doing of evil. There certainly [are evils that God does not cause]. Such evil could not occur unless someone caused it. But if you ask what those causes are, it is impossible to say since there is no single cause of evil. Rather, each person who does evil is the cause of his own evildoing. If you doubt this, then note what I said above: evil deeds are punished by the justice of God. They would not be punished justly if they were not performed willfully. [On Free Choice: 1:1]

Since the will undergoes movement when it turns from the unchangeable good to the changeable good, you may perhaps ask how this movement originates. It is really evil, though free will must be considered as a good, since it is impossible to live rightly without it. For if this movement, namely, the turning away of the will from the Lord, is unquestionably sinful, we could not say, could we, that God is the cause of sin? If this movement, therefore, does not come from God, then where does it come from? . . . . That movement of the soul’s turning away, which we admitted was sinful, is a defective movement, and every defect arises from non-being. Look for the source of this movement and be sure that it does not come from God. [On Free Choice, 2:20]

Suppose someone said, “It would not have been difficult or troublesome for an omnipotent God to have created everything so in such a way that no one would be wretched” … My answer is as follows: the order of creation from the highest to the lowest occurs by just degrees . . . . Neither sin nor unhappiness is necessary to the perfection of the universe. Rather, it is the souls which, simply because they are souls, are necessary to its perfection. If souls will to sin, they sin. If they have sinned, they become unhappy. . . . Punishment is used in such a way that it places natures in their right order (that is, where it is not a disgrace for them to be) and forces them to comply with the beauty of the universe, so that the punishment of sin corrects the disgrace of sin. [On Free Choice, 3:9]

An objection that ignorant people usually raise against this argument concerns the death of little children and the physical suffering with which we have often seem them afflicted…. My answer to these people is this: In view of the encompassing network of the universe and the whole creation (a network that is perfectly ordered in time and place, where not even one leaf of a tree is superfluous) it is not possible to create a superfluous person. . . . Moreover, who knows what faith is practiced or what pity is tested when these children’s sufferings break down the hardness of parents? We do not know what reward God reserves in the secret places of his judgment for these children . . . . [On Free Choice, 3.27]

Free will and Foreknowledge

Your trouble is this. You wonder how it can be that these two propositions are not contradictory, namely that God as foreknowledge of all future events, and that we sin voluntarily and not by necessity. For if, you say, God foreknows that a man will sin, he must necessarily sin. But if necessity there is no voluntary choice in sinning, but rather fixed and unavoidable necessity. You are afraid that by that reasoning the conclusion may be reached either that God’s foreknowledge of all future events must be impiously denied, or if that cannot be denied, that sin is committed not voluntarily but by necessity. . . . Thus, we believe both that God has foreknowledge of everything in the future and that nonetheless we will whatever we will. Since God foreknows our will, the very will that he foreknows will be what comes about. Therefore, it will be a will, since it is a will that he foreknows. And it could not be a will unless it were in our power. Therefore, he also foreknows this power. It follows, then, that his foreknowledge does not take away my power; in fact, it is all the more certain that I will have that power, since he whose foreknowledge never errs foreknows that I will have it. [On Free Choice, 3:3]

Unless I am mistaken, if you knew beforehand that a man was going to sin, you would not directly compel the man to sin. Nor does your foreknowledge in itself compel him to sin even though he was certainly going to sin, as we must assume if you have real foreknowledge. So there is no contradiction here. Simply you know beforehand what another is going to do with his own will. Similarly, God compels no man to sin, though he sees beforehand those who are going to sin by their own will. [On Free Choice, 3:4]

Two Cities

Two cities have been formed by two loves: the earthly by the love of self, even to the contempt of God; the heavenly by the love of God, even to the contempt of self. The former, in a word, glories in itself, the latter in the Lord. For the one seeks glory from men; but the greatest glory of the other is God, the witness of conscience. The one lifts up its head in its own glory; the other says to its God, “You are my glory, and you lift up my head.” In the one, the princes and the nations it subdues are ruled by the love of ruling; in the other, the princes and the subjects serve one another in love, the latter obeying, while the former take thought for all. The one delights in its own strength, represented in the persons of its rulers; the other says to its God, “I will love you, Lord, my strength.” [City of God, 14:28]

The families which do not live by faith seek their peace in the earthly advantages of this life; while the families which live by faith look for those eternal blessings which are promised, and use as pilgrims such advantages of time and of earth as do not fascinate and divert them from God, but rather aid them to endure with greater ease, and to keep down the number of those burdens of the corruptible body which weigh upon the soul. Thus the things necessary for this mortal life are used by both kinds of men and families alike, but each has its own peculiar and widely different aim in using them. The earthly city, which does not live by faith, seeks an earthly peace, and the end it proposes, in the well-ordered concord of civic obedience and rule, is the combination of men’s wills to attain the things which are helpful to this life. The heavenly city, or rather the part of it which sojourns on earth and lives by faith, makes use of this peace only because it must, until this mortal condition which necessitates it shall pass away. Consequently, so long as it lives like a captive and a stranger in the earthly city, though it has already received the promise of redemption, and the gift of the Spirit as the earnest of it, it makes no scruple to obey the laws of the earthly city, whereby the things necessary for the maintenance of this mortal life are administered; and thus, as this life is common to both cities, so there is a harmony between them in regard to what belongs to it. [City of God, 19:17]


Early medieval mystical philosopher influenced by Neoplatonism who emphasized describing God through negative attributes.

Positive and Negative Theology

  1. [I have previously] declared those matters which are properly the subject of positive theology; (a) in what sense the holy divine nature is one, and in what sense three; what it is that is there called Fatherhood, and what Sonship; and what the doctrine of the Holy Ghost signifies. . . . [I have also shown] (b) how God is called good, and how Being, how Life and Wisdom and Virtue, with other names spiritually applied to Him. Finally . . . [I have shown] (c) what names have been transferred to him from sensible things what is meant by the divine forms and figures, limbs, instruments, localities, adornments, fury, anger and grief; drunkenness, oaths and curses, sleep and waking, with other modes of sacred and symbolical nomenclature. … [My arguments there] took us from the highest to the lowest, and in the measure of this descent our treatment of it extended itself. Now, however, we rise from beneath to that which is the highest, and accordingly our speech is restrained in proportion to the height of our ascent; but when our ascent is accomplished, language will cease altogether, and be absorbed into the ineffable. . . .
  2. We say that the cause of all things, who is himself above all things, is (c) neither without being nor without life, nor without reason nor without intelligence; nor is he a body; nor has he form or shape, or quality or quantity or mass; he is not localized or visible or tangible; he is neither sensitive nor sensible; he is subject to no disorder or disturbance arising from material passion; he is not subject to failure of power, or to the accidents of sensible things; he needs no light; he suffers no change or corruption or division, or privation or flux; and he neither has nor is anything else that belongs to the senses.
  3. Again, ascending, we say that he is (b) neither soul nor intellect; nor has he imagination, nor opinion or reason; he has neither speech nor understanding, and is neither declared nor understood; he is neither number nor order, nor greatness nor smallness, nor equality nor likeness nor unlikeness; he does not stand or move or rest; he neither has power nor is power; nor is he light, nor does he live, nor is he life; he is neither being nor age nor time; nor is he subject to intellectual contact; he is neither knowledge nor truth, nor royalty nor wisdom; he is neither one nor unity, nor divinity, nor goodness; nor is he spirit, as we understand spirit. Neither is he (c) sonship nor fatherhood nor anything else known to us or to any other beings, either of the things that are or the things that are not; nor does anything that is, know him as he is, nor does he know anything that is as it is; he has neither word nor name nor knowledge; he is neither darkness nor light nor truth nor error; he can neither be affirmed nor denied; nay, though we may affirm or deny the things that are beneath him, we can neither affirm nor deny him; for the perfect and sole cause of all is above all affirmation, and that which transcends all is above all subtraction, absolutely separate, and beyond all that is. [Mystical Theology, 3-5]

BOETHIUS (480-524)

Early medieval philosopher who developed the problem of universals and argued that God exists outside of time.

God’s Eternality

God is eternal; in this judgment all rational beings agree. Let us, then, consider what eternity is. Now, eternity is the possession of endless life whole and perfect at a single moment. What this is becomes more clear and obvious when comparing it to temporal things. For whatever lives in time is a present thing that proceeds from the past to the future, and there is nothing set in time that can embrace the whole space of its life together. It does not yet grasp tomorrow’s state, while it has already lost yesterday’s. . . . Aristotle held that the world never had either a beginning or end, and its life stretched to the whole extent of time’s infinity; yet it could not properly be considered eternal. For it does not include and embrace the whole space of infinite life at once, and it has no present hold on things to come, or things yet accomplished. Accordingly, we may rightly call something eternal which includes and possesses the whole fullness of unending life at once, from which nothing future is absent, from which nothing past has escaped. This must of necessity be ever present to itself in full self-possession, and hold the infinity of movable time in a permanent present. . . . [Consolation of Philosophy, 5:6]

Foreknowledge and Free Will

Since God stands forever in an eternal present, his knowledge, also transcending all movement of time, dwells in the simplicity of its own changeless present. It embraces the whole infinite sweep of the past and of the future, contemplates all that falls within its simple cognition as if it were now taking place. And therefore, if you will carefully consider that immediate presentment whereby it discriminates all things, you will more rightly conclude that it is not foreknowledge as of something future, but knowledge of a moment that never passes. For this cause the name chosen to describe it is not pre-vision, but providence, because, since utterly removed in nature from things mean and trivial, its outlook embraces all things as from some lofty height. Why, then, do you insist that the things which are surveyed by the divine eye are involved in necessity? Clearly, people impose no necessity on things which they see? Does the act of vision add any necessity to the things that you see before your eyes? . . . Yet, if we may without unfitness compare God’s present and humans’ present, just as you see certain things in your temporary present, so too does he see all things in his eternal present. Thus, the divine anticipation does not change the natures and properties of things, and it beholds things present before it, just as they will hereafter come to pass in time. [Consolation of Philosophy, 5:6]


Medieval Christian philosopher who developed what is now called the ontological argument for God’s existence.

Proof for God from Absolute Goodness

Since there are goods so innumerable, whose great diversity we experience by the bodily senses, and discern by our mental faculties, must we not believe that there is some one thing, through which all goods whatever are good? . . . For, whatsoever things are said to be just, when compared one with another, whether equally, or more, or less, cannot be understood as just, except through the quality of justness, which is not one thing in one instance, and another in another.

Since it is certain, then, that all goods, if mutually compared, would prove either equally or unequally good, necessarily they are all good by virtue of some thing which is conceived of as the same in different goods, although sometimes they seem to be called good, the one by virtue of one thing, the other by virtue of another. . . .

It follows, therefore, that all goods are good through another being than that which they themselves are, and this being alone is good through itself. Hence, this alone is supremely good, which is alone good through itself. For it is supreme, in that it so surpasses other beings, that it is neither equaled nor excelled. But that which is supremely good is also supremely great. There is, therefore, some one being which is supremely good, and supremely great, that is, the highest of all existing beings. [Monologium 1]

Ontological Argument

I began to ask myself whether there might be found a single argument which would require no other for its proof than itself alone; and alone would suffice to demonstrate that God truly exists, and that there is a supreme good requiring nothing else, which all other things require for their, existence and well-being; and whatever we believe regarding the divine Being. [Proslogium, Preface]

Hence, even the fool is convinced that something exists in the understanding, at least, than which nothing greater can be conceived. For, when he hears of this, he understands it. And whatever is understood, exists in the understanding. And assuredly that, than which nothing greater can be conceived, cannot exist in the understanding alone. For, suppose it exists in the understanding alone: then it can be conceived to exist in reality, which is greater.

Therefore, if that, than which nothing greater can be conceived, exists in the understanding alone, the very being, than which nothing greater can be conceived, is one, than which a greater can be conceived. But obviously this is impossible. Hence, there is no doubt that there exists a being, than which nothing greater can be conceived, and it exists both in the understanding and in reality. [Proslogium, 2]

And it assuredly exists so truly, that it cannot be conceived not to exist. For, it is possible to conceive of a being which cannot be conceived not to exist; and this is greater than one which can be conceived not to exist. Hence, if that, than which nothing greater can be conceived, can be conceived not to exist, it is not that, than which nothing greater can be conceived. But this is an irreconcilable contradiction. There is, then, so truly a being than which nothing greater can be conceived to exist, that it cannot even be conceived not to exist; and this being you are, O Lord, our God. [Proslogium, 3]

God’s Attributes

What are you, then, Lord God, than whom nothing greater can be conceived? But what are you, except that which, as the highest of all beings, alone exists through itself, and creates all other things from nothing? For, whatever is not this is less than a thing which can be conceived of. But this cannot be conceived of you. What good, therefore, does the supreme Good lack, through which every good is? Therefore, you are just, truthful, blessed, and whatever it is better to be than not to be. For it is better to be just than not just; better to be blessed than not blessed. [Proslogium, 3]

Guanilo’s Criticism

For example: it is said that somewhere in the ocean is an island, which, because of the difficulty, or rather the impossibility, of discovering what does not exist, is called the lost island. And they say that this island has an inestimable wealth of all manner of riches and delicacies in greater abundance than is told of the Islands of the Blest; and that having no owner or inhabitant, it is more excellent than all other countries, which are inhabited by mankind, in the abundance with which it is stored.

Now if some one should tell me that there is such an island, I should easily understand his words, in which there is no difficulty. But suppose that he went on to say, as if by a logical inference: “You can no longer doubt that this island which is more excellent than all lands exists somewhere, since you have no doubt that it is in your understanding. And since it is more excellent not to be in the understanding alone, but to exist both in the understanding and in reality, for this reason it must exist. For if it does not exist, any land which really exists will be more excellent than it; and so the island already understood by you to be more excellent will not be more excellent.”

If a man should try to prove to me by such reasoning that this island truly exists, and that its existence should no longer be doubted, either I should believe that he was jesting, or I know not which I ought to regard as the greater fool: myself, supposing that I should allow this proof; or him, if he should suppose that he had established with any certainty the existence of this island. For he ought to show first that the hypothetical excellence of this island exists as a real and indubitable fact, and in no wise as any unreal object, or one whose existence is uncertain, in my understanding.

Anselm’s Reply to Guanilo

That being alone, on the other hand, cannot be conceived not to exist, in which any conception discovers neither beginning nor end nor composition of parts, and which any conception finds always and everywhere as a whole. . . . So, then, of God alone it can be said that it is impossible to conceive of his non­existence; and yet many objects, so long as they exist, in one sense cannot be conceived not to exist. But in what sense God is to be conceived not to exist, I think has been shown clearly enough in my book.

AVERROES (IBN RUSHD) (1126-1198)

Medieval Christian philosopher who developed what is now called the ontological argument for God’s existence.

The Relation between Religion and Philosophy

As this Law is true and leads to the consideration of the knowledge of God, we Muslims should believe that rational investigation is not contrary to Law, for truth cannot contradict truth, but verifies it and bears testimony to it. And if that is so, and rational observation is directed to the knowledge of any existent objects, then the Law may be found to be silent about it, or concerned with it. In the former case no dispute arises, as it would be equivalent to the absence of its mention in the Law as injunctory, and hence the jurist derives it from legal conjecture. But if the Law speaks of it, either it will agree with that which has been proved by inference, or else it will disagree with it. If it is in agreement it needs no comment, and if it is opposed to the Law, an interpretation is to be sought. Interpretation means to carry the meaning of a word from its original sense to a metaphorical one. But this should be done in such a manner as will not conflict with the custom of the Arabian tongue. It is to avoid the naming of an object, by simply mentioning its like, its cause, its attribute, or associate, etc. which are commonly quoted in the definition of the different kinds of metaphorical utterances. And if the jurist does so in many of the legal injunctions, how very befitting would it be for a learned man to do the same with his arguments. For the jurist has only his fanciful conjectures to depend upon, while a learned man possesses positive ones.

We hold it to be an established truth that if the Law is apparently opposed to a truth proved by philosophy it admits of an interpretation according to the canons of the Arabic language. This is a proposition which a Muslim cannot doubt and a believer cannot mistrust. One who is accustomed to these things divine can experience for himself what we have said. The aim of this discourse is to bring together intellectual and traditional science. Indeed, we would even say that no logical conclusion will be found to be opposed to the Law, which when sifted and investigated in its different parts will be found in accordance, or almost so, with it.

That is why all Muslims are agreed that all the words of the Law are not to be taken literally, nor all of them given an interpretation. But they vary in verses, which are or are not to be interpreted. . . . [Decisive Discourse, p. 28]

But there are things which, on account of their obscurity, cannot be understood by inference. So, God has favored such of his creatures as cannot understand logic, either on account of their nature, habit, or lack of mental training, by quoting examples and parables of such things and has urged them to testify as to their truth through them. For everyone has mental capacity enough to understand them by the help of dogmatic and exhortatory argument which are common to all men. This is why the Law has been divided into two kinds: exoteric and esoteric. The exoteric part consists of those examples which have been coined to express certain meanings; while the esoteric is the meanings themselves, which are not manifested except to the learned in philosophy.  . . . [p. 45]

There is a third part of the Law which occupies an intermediate position, on account of some doubt about it. Some say that it should be taken exoterically, and that no interpretation should be allowed in it; while there are others who say that they have some of esoteric meaning, and should not be taken exoterically by the learned. This is on account of the obscurity of their meaning. A learned man may be excused if he makes a mistake about them.

In short, all that should be interpreted can be grasped by philosophy alone. So the duty of the learned person is to interpret, and of the common people to take it literally, both in conception and in verification. The reason for the latter is that they cannot understand more. A student of law sometimes finds interpretations which have a preference over others, in a general way by verification: that is, the argument is more convincing with the interpretations than with the literal meanings. These interpretations are common and it is possible for them to be admitted by any whose speculative faculties have been developed in controversy. Some of the interpretations of the Asharites and the Mutazilites are of this type, though the arguments of the Mutazilites are generally the more weighty. But it is the duty of the common people who are not capable of understanding more than exhortation to take them exoterically. Indeed, it is not pro- per for them to know the interpretations at all.

Thus there are three groups into which men have been divided: Those who are not included amongst those who should know the interpretations. These are common people who are guided by exhortation alone. They form a vast majority: for there is not a single rational being who cannot accept a result by this method. The second are dogmatic interpreters. These are so, either by their nature only, or both by nature and habit. The third are those who can be definitely called interpreters. These are the philosophers, both by nature and by philosophical training. This kind of interpretation should not be discussed with the dogmatists, not to speak of the common people. If any of these interpretations are disclosed to those not fit to receive them–especially philosophical interpretations–these being far higher than common knowledge, they may be led to infidelity. [p. 58]


Medieval Spanish-Jewish philosopher influenced by Muslim philosophy who rejected literal interpretations of scripture in favor of allegorical ones.

Clarifying Religious Language

My primary object in this work is to explain certain words occurring in the prophetic books. Of these some are homonyms, and of their several meanings the ignorant choose the wrong ones ; other terms which are employed in a figurative sense are erroneously taken by such persons in their primary [literal] signification. There are also hybrid terms, denoting things which are of the same class from one point of view and of a different class from another. It is not here intended to explain all these expressions to the uneducated. . . . The object of this treatise is to enlighten a religious man who has been trained to believe in the truth of our holy Law, who conscientiously fulfils his moral and religious duties, and at the same time has been successful in his philosophical studies. Human reason has attracted him to abide within its sphere; and he finds it difficult to accept as correct the teaching based on the literal interpretation of the Law, and especially that which he himself or others derived from those homonymous, metaphorical, or hybrid expressions. Hence he is lost in perplexity and anxiety. [Guide for the Perplexed, Introduction]

Some have held the opinion that by the Hebrew word zelem [i.e., form] means the shape and figure of a thing, and this explanation has led some to believe in the corporeality of God [i.e., that God has a physical body]. For they thought that the words “Let us make man in our zelem [form]” implied that God had the form of a human being, that is, that He had figure and shape, and that, consequently, He was corporeal. They adhered faithfully to this view, and thought that if they were to reject it they would by doing so reject the truth of the Bible. And further, if they did not conceive God as having a body possessed of face and limbs, similar to their own in appearance, they would have to deny even the existence of God. . . . I hold that the Hebrew equivalent of [physical] “form” in the ordinary use of the word, that is, the figure and shape of a thing, is toar. Thus we find “[And Joseph was] beautiful in toar [i.e., physical form], and beautiful in appearance” (Gen. 39:6). . . This term is not at all applicable to God. The term zelem, on the other hand, signifies the specific form, that is, that which constitutes the essence of a thing, whereby the thing is what it is; the reality of a thing in so far as it is that particular being. [Guide for the Perplexed, 1.1]

THOMAS AQUINAS (1225–1274)

Medieval philosopher influenced by Aristotle who emphasized five proofs for God’s existence and morality grounded in natural law.

Faith and Reason

The truths that we confess concerning God fall into two categories. Some things that are true of God are beyond all the competence of human reason, such as that God is three and one. There are other things to which even human reason can attain, such as the existence and unity of God, which philosophers have proved to a demonstration under the guidance of the light of natural reason. . . . Human understanding cannot go so far with its natural power as to grasp God’s substance, since, under the conditions of the present life, knowledge and understanding begins with the senses. Therefore, objects beyond the senses cannot be grasped by human understanding except so far as knowledge is gathered of them through the senses. But things of sense cannot lead our understanding to discover in them the essence of the divine substance, since they are effects inadequate to the power that caused them. Nevertheless our understanding is thereby led to some knowledge of God, namely, of his existence and of other attributes that must necessarily be attributed to the first cause. [Summa Contra Gentiles, Book 1, Ch. 3]

Five Proofs of God

The existence of God can be proved in five ways.

The first and more manifest way is the argument from motion. It is certain, and evident to our senses, that in the world some things are in motion. Now whatever is in motion is put in motion by another, for nothing can be in motion except it is in potentiality to that towards which it is in motion; whereas a thing moves inasmuch as it is in act. For motion is nothing else than the reduction of something from potentiality to actuality. But nothing can be reduced from potentiality to actuality, except by something in a state of actuality. Thus that which is actually hot, as fire, makes wood, which is potentially hot, to be actually hot, and thereby moves and changes it. Now it is not possible that the same thing should be at once in actuality and potentiality in the same respect, but only in different respects. For what is actually hot cannot simultaneously be potentially hot; but it is simultaneously potentially cold. It is therefore impossible that in the same respect and in the same way a thing should be both mover and moved, i.e. that it should move itself. Therefore, whatever is in motion must be put in motion by another. If that by which it is put in motion be itself put in motion, then this also must needs be put in motion by another, and that by another again. But this cannot go on to infinity, because then there would be no first mover, and, consequently, no other mover; seeing that subsequent movers move only inasmuch as they are put in motion by the first mover; as the staff moves only because it is put in motion by the hand. Therefore it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be God.

The second way is from the nature of the efficient cause. In the world of sense we find there is an order of efficient causes. There is no case known (neither is it, indeed, possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible. Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause, whether the intermediate cause be several, or only one. Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first efficient cause, to which everyone gives the name of God.

The third way is taken from possibility and necessity, and runs thus. We find in nature things that are possible to be and not to be, since they are found to be generated, and to corrupt, and consequently, they are possible to be and not to be. But it is impossible for these always to exist, for that which is possible not to be at some time is not. Therefore, if everything is possible not to be, then at one time there could have been nothing in existence. Now if this were true, even now there would be nothing in existence, because that which does not exist only begins to exist by something already existing. Therefore, if at one time nothing was in existence, it would have been impossible for anything to have begun to exist; and thus even now nothing would be in existence—which is absurd. Therefore, not all beings are merely possible, but there must exist something the existence of which is necessary. But every necessary thing either has its necessity caused by another, or not. Now it is impossible to go on to infinity in necessary things which have their necessity caused by another, as has been already proved in regard to efficient causes. Therefore we cannot but postulate the existence of some being having of itself its own necessity, and not receiving it from another, but rather causing in others their necessity. This all men speak of as God.

The fourth way is taken from the gradation to be found in things. Among beings there are some more and some less good, true, noble and the like. But “more” and “less” are predicated of different things, according as they resemble in their different ways something which is the maximum, as a thing is said to be hotter according as it more nearly resembles that which is hottest; so that there is something which is truest, something best, something noblest and, consequently, something which is uttermost being; for those things that are greatest in truth are greatest in being, as it is written in Metaphysics. ii. Now the maximum in any genus is the cause of all in that genus; as fire, which is the maximum heat, is the cause of all hot things. Therefore there must also be something which is to all beings the cause of their being, goodness, and every other perfection; and this we call God.

The fifth way is taken from the governance of the world. We see that things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that not fortuitously, but designedly, do they achieve their end. Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God. [Summa Theologica, I, Q. 2, Art 3]

Accidental and Essential Causes

By faith alone do we hold, and by no demonstration can it be proved, that the world did not always exist.

In efficient causes it is impossible to proceed to infinity “per se”—thus, there cannot be an infinite number of causes that are “per se” required for a certain effect; for instance, that a stone be moved by a stick, the stick by the hand, and so on to infinity. But it is not impossible to proceed to infinity “accidentally” as regards efficient causes; for instance, if all the causes thus infinitely multiplied should have the order of only one cause, their multiplication being accidental, as an artificer acts by means of many hammers accidentally, because one after the other may be broken. It is accidental, therefore, that one particular hammer acts after the action of another; and likewise it is accidental to this particular man as generator to be generated by another man; for he generates as a man, and not as the son of another man. For all men generating hold one grade in efficient causes—viz. the grade of a particular generator. Hence it is not impossible for a man to be generated by man to infinity; but such a thing would be impossible if the generation of this man depended upon this man, and on an elementary body, and on the sun, and so on to infinity.

[Summa Theologica, 1, Q. 46, Art. 2]

Divine Simplicity

We can speak of simple things only as though they were like the composite things from which we derive our knowledge. Therefore in speaking of God, we use concrete nouns to signify His subsistence, because with us only those things subsist which are composite; and we use abstract nouns to signify His simplicity. In saying therefore that Godhead, or life, or the like are in God, we indicate the composite way in which our intellect understands, but not that there is any composition in God.

There is neither composition of quantitative parts in God, since He is not a body; nor composition of matter and form; nor does His nature differ from His person; nor His essence from His existence; neither is there in Him composition of genus and difference, nor of subject and accident. Therefore, it is clear that God is nowise composite, but is altogether simple. [Summa Theologica, Q 3, Art. 3, 7]

Religious Language

Univocal predication is impossible between God and creatures… [The] term “wise” is not applied in the same way to God and to man. The same rule applies to other terms. Hence no name is predicated univocally of God and of creatures. Neither, on the other hand, are names applied to God and creatures in a purely equivocal sense, as some have said. Because if that were so, it follows that from creatures nothing could be known or demonstrated about God at all. … Therefore it must be said that these names are said of God and creatures in an analogous sense, i.e. according to proportion. Now this mode of community of idea is a mean between pure equivocation and simple univocation. For in analogies the idea is not, as it is in univocals, one and the same, yet it is not totally diverse as in equivocals; but a term which is thus used in a multiple sense signifies various proportions to some one thing; thus “healthy” applied to urine signifies the sign of animal health, and applied to medicine signifies the cause of the same health. [Summa Theologica, 1, Q. 13, Art. 5]

Natural Law

Hence this is the first precept of law, that “good is to be done and pursued, and evil is to be avoided.” All other precepts of the natural law are based upon this: so that whatever the practical reason naturally apprehends as man’s good (or evil) belongs to the precepts of the natural law as something to be done or avoided.

Since, however, good has the nature of an end, and evil, the nature of a contrary, hence it is that all those things to which man has a natural inclination, are naturally apprehended by reason as being good, and consequently as objects of pursuit, and their contraries as evil, and objects of avoidance. Wherefore according to the order of natural inclinations, is the order of the precepts of the natural law. Because in man there is first of all an inclination to good in accordance with the nature which he has in common with all substances: inasmuch as every substance seeks the preservation of its own being, according to its nature: and by reason of this inclination, whatever is a means of preserving human life, and of warding off its obstacles, belongs to the natural law. Secondly, there is in man an inclination to things that pertain to him more specially, according to that nature which he has in common with other animals: and in virtue of this inclination, those things are said to belong to the natural law, “which nature has taught to all animals” [Pandect. Just. I, tit. i], such as sexual intercourse, education of offspring and so forth. Thirdly, there is in man an inclination to good, according to the nature of his reason, which nature is proper to him: thus man has a natural inclination to know the truth about God, and to live in society: and in this respect, whatever pertains to this inclination belongs to the natural law; for instance, to shun ignorance, to avoid offending those among whom one has to live, and other such things regarding the above inclination.

[Summa Theologica, la-2ae, Q. 94, Art. 2]

DUNS SCOTUS (1266-1308)

Medieval philosopher who criticized divine illumination and advocated divine command morality.

Against Divine Illumination

God, therefore, insofar as he is able to act in accord with those right laws he set up previously, is said to act according to his ordained power; but insofar as he is able to do many things that are not in accord with, but go beyond, these [divinely] preestablished laws, God is said to act according to his absolute power. For God can do anything that is not self-contradictory or act in any way that does not include a contradiction (and there are many such ways he could act); and then he is said to be acting according to his absolute power. [Oxford Commentary, 1:44]

Morality and Natural Law

To kill, to steal, to commit adultery, are against the precepts of the Ten Commandments, as is clear from Exodus [20:13]: “You shall not kill” [etc.]. Yet God seems to have dispensed from these. This is clear in regard to homicide from Genesis 22, regarding Abraham and the son he was about to sacrifice; or for theft from Exodus 11:[2] and [12:35] where he ordered the sons of Israel to despoil the Egyptians, which despoilment is taking what belongs to another without the owner’s consent, which is the definition of theft. As for the third, there is Hosea 1: “Make children of fornications.” . . .

In reply to the question, therefore, I say that something can be said to belong to the law of nature in two ways: in one way, as a practical first principle, known from terms or as a conclusion necessarily following from it. And these are said to belong to the law of nature most strictly. . . . None of the precepts of the second table of the Commandments [i.e., don’t kill, don’t steal] are of this kind, since the grounds for what is there commanded or forbidden are not unconditionally necessary practical principles nor unconditionally necessary conclusions [i.e., they are not required for goodness]. . . . . But it is otherwise concerning the precepts of the first table, since they pertain immediately to God as their object. The two first, if they are understood to be merely negative: “Do not have foreign gods,” and “do not take the name of God in vain,” that is, do not be irreverent to your God belong strictly to the law of nature. For it follows necessarily that if he is God, he should be loved as God, and that nothing else is to be honored as God, nor is irreverence to be committed toward God. And consequently, God will not be able to grant dispensation from these, so that one could lawfully do the opposite of what is thus prohibited. . . .

Some things are said to belong to the law of nature in another way, since a great deal is consistent with that law although it does not necessarily follow from practical principles necessarily known from the terms to every apprehending intellect. It is certain that in this way all the precepts of the second table belong to the law of nature, since their rightness is surely consistent with necessarily known practical first principles. [Oxford Commentary, 3:37]


Medieval philosopher who advocated a principle of simplicity (Ockham’s razor), nominalism regarding universals, and ethical divine command theory.

The Razor

Nothing should be posited as naturally necessarily required for some effect unless certain experience or a certain argument from what is self-evident leads to that; but neither of these leads to the positing of a universal species. [Commentary on the Sentences, Bk. 2, Q. 15]


That a universal is not a substance existing outside the mind can in the first place be evidently proved as follows: . . . If a universal were one substance existing in singular things and distinct from them, it would follow that it could exist apart from them; for every thing naturally prior to another thing can exist apart from it by the power of God. But this consequence is absurd. Furthermore, . . . it would follow that God could not annihilate one individual of a substance without destroying the other individuals. For if he annihilated one individual, he would destroy the whole of the essence of the individual, and consequently he would destroy the universal which is in it and in others. Consequently, the other individuals do not remain, since they cannot remain without a part of themselves, such as the universal is held to be. . . . Furthermore, we could not assume such a universal to be something entirely external to the essence of an individual; therefore, it would be of the essence of the individual, and consequently the individual would be composed of universals; and thus the individual would not be more singular than universal. Furthermore, it follows that something of the essence of Christ would be miserable and damned; since that common nature which really exists in Christ, really exists in Judas also and is damned. Therefore, something is both in Christ and in one who is damned, namely in Judas. That, however, is absurd. . . . From these and many other texts it is clear that a universal is a mental content of such nature as to be predicated of many things. This can also be confirmed by reason. All agree that every universal is predicated of things. But only a mental content or conventional sign, not a substance, is of such a nature as to be predicated. Consequently, only a mental content or a conventional sign is a universal. [Summa Totius Logica 1:15:5]

Divine Command

I reply that hatred, theft, adultery, and the like may involve evil according to the common law, in so far as they are done by someone who is obligated by a divine command to perform the opposite act. As far as everything absolute in these actions is concerned, however, God can perform them without involving any evil. And they can even be performed meritoriously by someone on earth if they should fall under a divine command, just as now the opposite of these, in fact, fall under a divine command. [Opera Theologica V, p. 352]

Every will can conform to the commands of God. God can, however, command a created will to hate Him. Therefore, the created will can do this. Moreover, any act that can be just on earth could also be just in heaven. On earth the hatred of God can be just, if it is commanded by God Himself. Therefore, the hatred of God could also be just in heaven. [Fourth Book of the Sentences, 13]


Platonist renaissance Humanist who emphasized human uniqueness.

The Platonic Great Chain of Being

Platonists distinguish created things into three degrees. The first includes physical and visible things, such as the sky, the elements, and everything made from them. The third is the invisible and nonphysical, which are completely free from bodies and which are properly called “intellectual natures” and are divine and angelical. Between these is a middle nature, which though nonphysical, invisible, and immortal, they nevertheless move bodies, as is necessary for their function. These are called “rational souls” and are inferior to angels yet superior to bodies. They are ruled by the angels, yet are rulers of bodies.  Above all of these is God himself, the author and principle of every creature, and in him divinity has a causal existence. It is from him that divinity proceeds to the angels in their formal existence, and from there divinity is derived into rational souls through participation in their luster. Below that nature nothing can assume the title of the divine. [A Platonic Discourse on Love, 1.2]

Place of Humans in the Great Chain

By the laws of his hidden wisdom, God the father and master architect built this worldly home which we observe, a most sacred temple of his divinity. The areas above the heavens he gave minds. He gave animated souls to the celestial spheres. He filled the dregs of the lower world with a variety of animals. But when finished, the architect wished that there would be someone to appreciate the work, to love its beauty, and marvel at its size. Thus, all other things finished, as Moses and Timaeus report, he finally considered creating man. But there was nothing in his archetypes from which he could form new progeny, nor anything in his supply house which he might bequeath to a new son, nor was there an empty chair in which this new being could sit and contemplate the world. All places were filled. Everything had been assigned in the highest, middle, and lowest orders. But in this last task, it was not part of the Father’s power to give up as though exhausted. It was not part of his wisdom to waver because of a lack of a clear plan. It was not part of his living kindness that he should be praised for his generosity to others, but condemned for lack of it on himself. Finally, the master architect declared that this creature, to whom nothing unique could be given, should be a composite, and have that which belonged exclusively to all other things.

Thus, God took humanity, creatures of indeterminate form, placed them in a middle place in the world, and said the following: “I have given you, Adam, neither a fixed place nor a fixed form of your own. You may possess any place or any form as you desire. The laws ordained by me establish a limited nature for all other creatures. In accord with your free will, your destiny is in your own hands and you are confined to no bounds. You will fix the limits of your nature yourself. I have put you in the world’s center so that you may look around and examine the world’s content. I have made you neither heavenly nor earthly, neither mortal nor immortal. You may freely and honorably mold, make, and sculpt yourself into any shape you prefer. You can degenerate into the forms of the lower animals, or climb upward by your soul’s reason, to a higher nature which is divine.” What great generosity of God the Father! What great and wonderful happiness of humanity! [Oration on Human Dignity]

MARTIN LUTHER (1483–1546)

German theologian who launched the Protestant Reformation in 1517 and criticized the use of Aristotle in philosophy and theology.

Against Aristotle

The universities also require a good, sound reformation. I must say this, let it bother whom it may. The fact is that whatever the papacy has ordered or instituted is only designed for the propagation of sin and error. What is the present state of universities, but, as the book of Maccabees says, “schools of ‘Greek fashion’ and ‘heathenish manners’” (2 Macc. 4:12-13)? They are full of dissolute living, where very little is taught of the Holy Scriptures and of the Christian faith, and the blind heathen teacher, Aristotle, rules even more than Christ. My advice is that the books of Aristotle, the Physics, the Metaphysics, On the Soul, and the Ethics, which have up till the present been considered the best, be altogether abolished along with all others that claim to examine nature, though nothing can be learned from them, either of natural or spiritual things. Besides, no one has been able to understand his meaning, and much time has been wasted and many noble souls bothered with much useless labor, study, and expense. I venture to say that any potter has more knowledge of natural things than is to be found in these books. My heart is saddened to see how many of the best Christians have been fooled and led astray by the false words of this cursed, proud, and dishonest heathen. God sent him as a plague for our sins.

Doesn’t the wretched man in his best book, On the Soul, teach that the soul dies with the body, though many have tried to save him with vain words? It is as if we didn’t have the Holy Scriptures to teach us everything completely of which Aristotle had not the slightest perception. Yet this dead heathen has conquered, and has hindered and almost suppressed the books of the living God. Thus, when I see all this misery, I cannot help but think that the evil spirit has introduced this study.

Then there is the Ethics, which is accounted one of the best, though no book is more directly contrary to God’s will and the Christian virtues. Oh that such books could be kept out of the reach of all Christians! Let no one object that I say too much, or speak without knowledge. My friend, I know what I’m talking about. I know Aristotle as well as you or people like you. I have read him with more understanding than St. Thomas or Scotus, which I may say without arrogance, and can prove this if I need to. It doesn’t matter that so many great minds have exercised themselves in these topics for hundreds of years. Such objections do not affect me as they might have done once, since it is plain as day that many more errors have existed for hundreds of years in the world and the universities. I would, however, gladly consent that Aristotle’s books on Logic, Rhetoric, and Poetics, should be retained, or they might be usefully studied in a condensed form so that young people can practice speaking and preaching. But the notes and comments should be eliminated. Just as Cicero’s Rhetoric is read without note or comment, Aristotle’s Logic should be read without such long commentaries. But now neither speaking nor preaching is taught out of them, and they are used only for argumentation and toil. [Appeal to the German Nobility]

JOHN CALVIN (1509–1564)

French Protestant reformer who emphasized human depravity and predestination.

Sense of Divinity

We hold to be beyond dispute that there exists in the human minds and indeed by natural instinct, some sense of divinity. This is so since, to prevent any person from pretending ignorance, God himself has given all people some idea of his Godhead. He constantly renews and occasionally enlarges our memory of this. Thus, being aware that there is a God, and that he is their Maker, people may be condemned by their own conscience when they neither worship him nor consecrate their lives to God’s service. Certainly, if there is any quarter where it may be supposed that God is unknown, the most likely for such an instance to exist is among the dullest tribes farthest removed from civilization. But, as a heathen writer tells us, there is no nation so barbarous, no race so brutish, as not to be endowed with the conviction that there is a God. Even those who in other respects seem to differ very little from the lower animals, constantly retain some sense of religion. This common conviction is thoroughly possessed in the mind and firmly stamped on the breasts of all people. Since, then, there never has been, from the very first, any quarter of the globe, any city, any household even, without religion, this amounts to a tacit confession, that a sense of divinity is inscribed on every heart. No, even idolatry is ample evidence of this fact. For we know how reluctant humans are to lower themselves, in order to set other creatures above them. Therefore, when he chooses to worship wood and stone rather than be thought to have no God, it is evident how very strong this impression of a Deity must be. For, it is more difficult to obliterate it from the minds of people, than to break down the feelings of his nature. These feelings are certainly being broken down, though, when, in opposition to his natural haughtiness, he spontaneously humbles himself before the meanest object as an act of reverence to God. [Institutes, 1.3.1]


No pious person could simply deny the predestination by which God adopts some to the hope of life, and pronounces others to eternal death. But it is greatly undermined especially by those who make foreknowledge its cause. We, indeed, ascribe both foreknowledge and predestination to God. But we say, that it is absurd to make the latter subordinate to the former. When we attribute foreknowledge to God, we mean that all things always were, and ever continue, under his eye. To God’s knowledge there is no past or future, but all things are present. Indeed, all things are so present, that it is not merely the idea of them that is before God (such as objects which we retain in our memories) but that he truly sees and contemplates them as actually under his immediate inspection. This foreknowledge extends to the whole circuit of the world, and to all creatures.

By predestination we mean the eternal decree of God, by which he determined with himself whatever he wished to happen with regard to every person. All are not created on equal terms, but some are preordained to eternal life, others to eternal damnation. Accordingly, as each has been created for one or other of these ends, we say that each person has been predestined to life or to death. God has testified this not only in the case of single individuals, but with communities too. This was so of all future generations of Abraham, to make it plain that the future condition of each nation lives entirely at his disposal. [Instututes, 3.21.5]


French philosopher and essayist influenced by the Pyrrhonian skeptical tradition.


It is faith alone that grasps the deep mysteries of our religion. I do not say, though, that it is not a brave and admirable attempt to use our God-given natural and human abilities to the service of our faith. It is undoubtedly the most noble use we can put them to…. Consider: reason is so blind that there is no faculty clear enough to distinguish the easy and the hard; nature in general challenges reason’s authority and rejects its mediation in all subjects equally; what does Truth mean when she preaches to us to reject worldly philosophy, or when she so frequently dictates to us “that our wisdom is folly in the sight of God? The vainest of all vanities is humanity; the person who presumes upon his wisdom does not yet know what wisdom is; a person seduces and deceives himself if he thinks himself to be something when in fact he is nothing.” These sentences of the Holy Ghost [from the Bible] clearly and vividly express what I am saying, and I need no other proof against people who would submit to the Holy Spirit’s authority with humility and obedience. But those others will not tolerate anyone to oppose their reasoning, except by reasoning itself; thus they will be punished at their own expense.


The profession of the Pyrrhonians is to waver, to doubt, to inquire, and never be assured of anything nor explain himself. Of the three functions or faculties of the soul (i.e. the imaginative, the appetite, and the consenting), they follow the first two, but the last they believe is ambiguous and hold neither one side nor the other with approval or inclination. … This straight and inflexible attitude of their judgment, receiving all objects without adoption or consent, leads them to their tranquility. This is the condition of a quiet and settled life, which is exempt from the agitations which we receive by the impression of the opinion and knowledge which we imagine to have of things. . . . They argue only mildly. They do not fear rebuttal or contradiction in their arguments. When they say that heavy things fall downward, they would hate to be believed and wish to be contradicted. This, in turn, brings about doubt and suspense of judgment, which is their purpose. They put forward their propositions only to criticize those they imagine we believe in. If you take their side, then they will try to maintain the opposite view. It is all the same to them, nor do they have a preference. If you propose that snow is black, they will argue on the other side that snow is white. If you say it is neither one nor the other, they will maintain that it is both.

… I understand why the Pyrrhonian philosophers cannot by any manner of speech express their general conception. To do so, they would need a new language. Our language is completely composed of affirmative propositions, which are directly against the Pyrrhonians. Thus, when they say “I doubt” you have them by the throat to make them admit that they doubt; at least you are assured of and know this. So they have been compelled to save themselves with the following comparison from medicine, without which their attitude would be inexplicable. When they say, “I don’t know,” or “I doubt,” they say, that this proposition expels itself along with other propositions, just as rhubarb [i.e. a laxative] purges one of bad humors and is itself purged. This attitude is more clearly seen in the question “What do I know?” I bear these words as inscribed on a pair of balances. . . .

When we say that the infinity of ages, as well past as to come, are but one instant with God; that His goodness, wisdom, and power are the same with His essence, our mouths speak it, but our understandings do not grasp it. And yet such is our outrageous opinion of ourselves, that we must make the divinity pass through our filter. From this proceed all the dreams and errors with which the world abounds, when we reduce and weigh in our balance a thing so far above our position. [Essays, 2.12]


It seems to me that the power of custom is rightly conveyed by the person who first invented this story. A country woman accustomed herself to play with and carry a young calf in her arms, and did so daily as it grew up. By this custom, when grown to be a great ox, she was still able to carry it.  In truth, custom is a violent and treacherous teacher.  Little by little, she slyly and imperceptibly slips in the foot of her authority. But after this gentle and humble beginning, when it becomes fixed and established through the benefit of time, she then unmasks a furious and tyrannical appearance, against which we have no more the courage or the power as to even lift up our eyes.  At every turn we see her forcing and violating the rules of nature: “Custom is the best master of all things.” . . .

[There are societies] where they boil the bodies of their dead, and afterwards pound them to a pulp, which they mix with their wine, and drink it; where the most coveted burial is to be eaten by dogs; . . . where they live in that rare and unsociable opinion of the mortality of the soul; . . . where women urinate standing and men squatting; where they send their blood in a token of friendship . . . where the children nurse for four years, and often twelve; … where they circumcise the women;  . . . in another it is reputed a holy duty for a man to kill his father at a certain age; . . . where children of seven years old endured being whipped to death, without changing expression.

The laws of conscience, which we pretend to be derived from nature, proceed from custom. Since everyone has an inward reverence for the opinions and manners approved of and received among his own people, no one can, without very great reluctance, depart from them, or apply himself to them without approval. [Essays, “Of Custom”]

BLAISE PASCAL (1623–1662)

French religious philosopher of the fideist tradition who proposed that we wager in favor of belief in God when reason is neutral.

Reason and Skepticism

Montaigne is wrong. Custom should be followed only because it is custom, and not because it is reasonable or just. But people follow it for this sole reason, that they think it just. Otherwise they would follow it no longer, although it were the custom; for they will only submit to reason or justice. Custom without this would pass for tyranny; but the sovereignty of reason and justice is no more tyrannical than that of desire. They are principles natural to man. [Thoughts, 325]

There is nothing so conformable to reason as this disavowal of reason

If we submit everything to reason, our religion will have no mysterious and supernatural element. If we offend the principles of reason, our religion will be absurd and ridiculous.

All our reasoning reduces itself to yielding to feeling. But fancy is like, though contrary to, feeling, so that we cannot distinguish between these contraries. One person says that my feeling is fancy, another that his fancy is feeling. We should have a rule. Reason offers itself; but it is pliable in every sense; and thus there is no rule. [Thoughts, 273-274]

The Wager

Let us examine this point then, and say “God is, or he is not.” But to which side shall we incline? Reason cannot decide it at all. There is an infinite chaos that separates us. A game is being played at the extremity of this infinite distance in which heads or tails must come up. Which will you take? By reason you can wager on neither. By reason you can hinder neither from winning.

Do not, then, charge those with falsehood who have made a choice. For you know nothing about it. “No. But I blame them for having made, not this choice, but a choice. For although he who takes heads, and the other, are in the same fault, they are both in fault. The proper way is simply not to wager.”

            Yes, but you must wager. This is not voluntary. You have set sail. Which will you take? Let’s see. Since a choice must be made, let’s see which interests you the least. You have two things to lose: the true and the good. And you have two things to stake: your reason and your will; that is, your knowledge and your complete happiness. And your nature has two things to shun: error and misery. Your reason is not more wounded, since a choice must necessarily be made in choosing one rather than the other. Here a point is eliminated. But what about your happiness? Let us weigh the gain and the loss in taking heads that God exists. Let us weigh these two cases. If you gain, you gain all. If you lose, you lose nothing. Wager without hesitation, then, that he is.

“This is admirable. Yes, it is necessary to wager, but perhaps I wager too much.” Let us see. Since there is equal risk of gaining or losing, if you had to gain but two lives for one, still you might wager. But if there were three lives to gain, it would be required to play (since you are under the necessity of playing). And, when you are forced to play, you would be imprudent not to risk your life in order to gain three in a play where there is equal hazard of loss and gain. But there is an eternity of life and happiness. And this being true, even if there were an infinity of chances (only one of which might be for you) you would still be right in wagering one in order to have two. And being obliged to play, if there was an infinity of life infinitely happy to gain, you would act foolishly to refuse to play one life against three in a game where among an infinity of chances there is one for you. But there is here an infinity of life infinitely happy to gain. And there is a chance of gain against a finite number of chances of loss, and what you play is finite. This [the balance of gain over loss] is quite settled. Wherever the infinite is, and where there is not an infinity of chances of loss against the chance of gain, there is nothing to weigh, and we must give all. And thus, when we are forced to play, we must renounce reason in order to keep life, rather than to risk it for the infinite gain, which is as likely to occur as the loss of nothingness. . . .

“I confess it, I admit it. But, still, are there no means of seeing the truth behind the game?” Yes, the scriptures and the rest.

“Yes, but my hands are tied and my mouth is dumb. I am forced to wager, and I am not free. I am chained and so constituted that I cannot believe. What will you have me do then?”

It is true. But at least learn your inability to believe, since reason brings you to such belief [given the above reasoning], and yet you cannot believe. Try then to convince yourself not by the addition of proofs for the existence of God, but by the reduction of your own passions. You would have recourse to faith, but don’t know the ways. You wish to be cured of infidelity, and you ask for the remedy. Learn it from those who have been bound like yourself, and who would wager now all their goods. These know the road that you wish to follow, and are cured of a disease that you wish to be cured of. Follow their course, then, from its beginning. It consisted in doing all things as if they believed in them, in using holy water, in having masses said, etc. Naturally this will make you believe and astonish you at the same time. “But this is what I fear.” And why? What have you to lose? [Thoughts, 233 (418)]


Renaissance Italian scientist who defended the sun-centered system and argued for the separation of science and religion.

Science and Religion

The Bible, although dictated by the Holy Spirit, admits … in many passages of an interpretation other than the literal one. And, moreover, we cannot maintain with certainty that all interpreters are inspired by God. Therefore, I think it would be the part of wisdom not to allow any one to apply passages of Scripture in such a way as to force them to support as true any conclusions concerning nature, the contrary of which may afterwards be revealed by the evidence of our senses, or by actual demonstration. Who will set bounds to human understanding? Who can assure us that everything that can be known in the world is known already? … I am inclined to think that Holy Scripture is intended to convince people of those truths which are necessary for their salvation, and which being far above human understanding cannot be made credible by any learning, or by any other means than revelation.

But it seems to me that I am not bound to believe that the same God who has endowed us with senses, reason, and understanding, does not permit us to use them, and desires to acquaint us in another way [that is, through revelation or religious authority] with such knowledge as we are in a position to acquire for ourselves by means of those faculties. This is especially so concerning those sciences about which the Holy Scriptures contain only small fragments and varying explanations. And this is precisely the case with astronomy, of which there is so little that the planets are not all enumerated, only the sun and moon, and once or twice Venus under the name of Lucifer. This, therefore, being granted, I think that in discussing natural phenomena we ought not to begin with texts from Scripture, but with experiment and demonstration. For, from the Divine Word, both Scripture and Nature do alike proceed. And I can see that that which experience sets before our eyes concerning natural effects, or which demonstration proves to us, ought not on any account to be called in question, much less condemned, upon the testimony of Scriptural texts, which may (under their mere words) have meanings of a contrary nature. [Letter to Benedetto Castelli]

FRANCIS BACON (1561-1626)

British philosopher who argued in favor of inductive reasoning in science, as opposed to deductive reasoning.

Induction and Deduction

1:1. Man, who is the servant and interpreter of nature, can act and understand no further than he has observed in either the operation or the contemplation of the method and order of nature.

1:12. The [deductive] logic now in use serves rather to fix and give stability to the errors which have their foundation in commonly received notions, rather than to help the search after truth. So it does more harm than good.

1:13. The syllogism is no match for the subtlety of nature. Thus, it is not applied to the first principles of sciences, and is applied in vain to intermediate axioms. It commands assent therefore to the [concluding] proposition, but does not take hold of the thing [in nature].

1.14. The syllogism consists of propositions, propositions of words; words are the signs of notions. If, therefore, the notions (which form the basis of the whole) be confused and carelessly abstracted from things, there is no solidity in the superstructure. Our only hope, then, is in genuine induction.

1:18. The discoveries which have previously been made in the sciences are such as lie close to common notions, scarcely beneath the surfaces. In order to penetrate into the inner and further recesses of nature, it is necessary that both notions and axioms be derived from things by a more sure and guarded way. It is necessary that a better and more certain method of intellectual operation be introduced altogether.

1:19. There are and can be only two ways of searching into and discovering truth. The one flies away from the senses and particulars, and instead starts with the most general principles. It simply assumes that the truth of these is settled and immovable. From these general principles it proceeds to judgment and to the discovery of middle principles. And this way is now in fashion. The other way derives general principles from the senses and particulars, rising gradually and continually, so that it arrives at the most general principles last of all. This is the true way, but as yet untried.

Four Idols

1:39. There are four classes of Idols which invade people’s minds. To these for distinction’s sake I have assigned names, calling the first class Idols of the Tribe, the second, Idols of the Cave, the third, Idols of the Marketplace, the fourth, Idols of the Theater.

1:40. The formation of ideas and axioms by true induction is no doubt the proper remedy to be applied for the keeping off and clearing away of idols. To point them out, however, is of great use. For the doctrine of Idols is to the Interpretation of Nature what the doctrine of the refutation of sophisms is to common logic.

1:41. The Idols of the Tribe have their foundation in human nature itself, and in the tribe or race of people. For it is a false assertion that the sense of man is the measure of things. On the contrary, all perceptions as well of the sense is of the mind are according to the measure of the individual and not according to the measure of the universe. And the human understanding is like a false mirror which, receiving rays irregularly, distorts and discolors the nature of things by mingling its own nature with it.

1:42. The Idols of the Cave are the idols of the individual person. For everyone (besides the errors common to human nature in general) has a cave or den of his own, which refracts and discolors the light of nature. This owes either to his own proper and peculiar nature, or to his education and conversation with others, or to the reading of books, and the authority of those whom he esteems and admires, or to the differences of impressions, accordingly as they take place in a mind preoccupied and predisposed or in a mind indifferent and settled, or the like. So that the spirit of humanity (according as it is limited to different individuals) is in fact a variable thing and full of perturbation, and governed as it were by chance. For this reason, it was well observed by Heraclitus that people look for sciences in their own lesser worlds, and not in the greater or common world.

1:43. There are also Idols formed by the communication and association of people with each other. I call these Idols of the Marketplace because of the exchange and association of people there. For it is by discourse that people associate. And words are imposed according to the understanding of the common people. And therefore the ill and unfit choice of words wonderfully obstructs the understanding. The matter is not set right by the definitions or explanations of some things which educated people use to guard and defend themselves. But words plainly force and overrule the understanding, and throw all into confusion, and lead men away into numberless empty controversies and idle fancies.

1:44. Lastly, there are Idols which have immigrated into people’s minds from the various dogmas of philosophies, and also from wrong laws of demonstration. These I call Idols of the Theater, because in my judgment all the received systems are but so many stage-plays, representing worlds of their own creation after an unreal and scenic fashion. Nor is it only of the systems now in vogue, or only of the ancient sects and philosophies, that I speak. For many more plays of the same kind may yet be composed and in like artificial manner set forth; since errors which are most widely different have nevertheless causes for the most part alike. Neither again do I mean this only of entire systems, but also of many principles and axioms in science, which by tradition, credulity, and negligence have come to be received.

Tables of Presence, Absence and Degrees

2:11. The investigation of forms proceeds as follows. A nature is given [e.g. heat], and we must first of all collect and present to our understanding all known instances which have this particular nature [e.g. all hot things], even in substances which are dissimilar. And such a collection must be made in the manner of a history, without premature speculation, or any great amount of subtlety. For example let the investigation be into the form of heat.

Instances agreeing in the nature of heat: 1. The rays of the sun, especially in summer and at noon. 2. The rays of the sun reflected and condensed, as between mountains, or on walls, and most of all in burning-glasses and mirrors. 3. Fiery meteors. 4. Burning thunderbolts. . . . This table I call the “Table of Essence and Presence.”

2:12. Secondly, we must present to the understanding those instances in which a given nature is wanting. This is because, as stated above, the above form should no less to be absent when the given nature is absent, than present when it is present. But to note all these would be endless.

The negatives should therefore be attached to the affirmatives, and the absence of the given nature [e.g. heat] inquired of only in those subjects that are most close to the others in which it is present and forthcoming. This I call the “Table of Deviation,” or of “Absence in Proximity.”

Instances in proximity where the nature of heat is absent: 1. To the first [on the above chart]: The rays of the moon and of stars and comets are not found to be hot to the touch; indeed the severest colds are observed to be at the full moons. . . .

2:13. Thirdly we must present to the understanding instances in which the nature under inquiry is found in different degrees, more or less. This must be done by making a comparison either of its increase and decrease in the same subject, or of its amount in different subjects, as compared one with another. For, the form of a thing is the very thing itself. And the thing itself differs from the form no differently than as the apparent differs from the real, or the external from the internal, or the thing in reference to mankind from the thing in reference to the universe. Thus, it necessarily follows that no nature can be assumed to be the true form unless it always decreases when the nature in question decreases, and in like manner always increases when the nature in question increases. Therefore, this Table I call the “Table of Degrees” or the “Table of Comparison.”

Table of Degrees or Comparison in heat. . . . 27. Motion increases heat, as you may see in bellows, and by blowing. This is in view of the fact that harder metals are not dissolved or melted by a dead or quiet fire until it is made intense by blowing.

            2:15. The work and office of these three tables I call the “Presentation of Instances to the Understanding.” Once this presentation is made, induction itself must be set at work. For, upon a review of each and every instance, the problem is to find such a nature that is always present or absent with the given nature [e.g. heat], and always increases and decreases with it, and which is (as I have said) a particular case of a more general nature.

ISAAC NEWTON (1642-1727)

British astronomer and mathematician who offered empirical rules of scientific reasoning and defended the design argument for God.

Rules of Reasoning in Science

Rule 1: We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances.

To this purpose the philosophers say that nature does nothing in vain, and more is in vain when less will serve. For nature is pleased with simplicity and affects not the pomp of superfluous causes.

Rule 2: Therefore to the same natural effects we must, as far as possible, assign the same causes.

As to respiration in a man and in a beast, the descent of stones in Europe and in America, the light of our culinary fire and of the sun, the reflection of light in the earth and in the planets.

Rule 3. The qualities of bodies, which admit neither intensification nor remission of degrees, and which are found to belong to all bodies within the reach of our experiments, are to be esteemed the universal qualities of all bodies whatsoever.

For since the qualities of bodies are only known to us by experiments, we are to hold for universal all such as universally agree with experiments, and such as are not liable to diminution can never be quite taken away. …

Rule 4. In experimental philosophy we are to look upon propositions inferred by general induction from phenomena as accurately or very nearly true, notwithstanding any contrary hypotheses that may be imagined, till such time as other phenomena occur by which they may either be made more accurate or liable to exceptions.

This rule we must follow, that the argument of induction may not be evaded by hypotheses.

Design Argument for God

Were all the planets as swift as Mercury or as slow as Saturn or his satellites [i.e. its moons]; or were the several velocities otherwise much greater or less than they are (as they might have been had they arose from any other cause than their gravities); or had the distances from the centers about which they move been greater or less than they are (as they might have been had they arose from any other cause than their gravities); or had the quantity of matter in the sun or in Saturn, Jupiter, and the earth (and by consequence their gravitating power) been greater or less than it is; [then, in any of these cases,] the primary planets could not have revolved about the sun nor the secondary ones about Saturn, Jupiter, and the earth, in concentric circles as they do, but would have moved in hyperbolas or parabolas or in ellipses very eccentric. To make this system, therefore, with all its motions, required a cause which understood and compared together the quantities of matter in the several bodies of the sun and planets and the gravitating powers resulting from thence…. And to compare and adjust all these things together in so great a variety of bodies, [such a design] argues that cause to be, not blind and fortuitous, but very well skilled in mechanics and geometry. [Letters to Richard Bentley, 1]

HUGO GROTIUS (1583-1645)

Dutch political philosopher who developed theories of natural law and just war.

Natural Law

  1. . . .[Carneades argued that] there is no law of nature, because all creatures, men as well as animals, are impelled by nature toward ends advantageous to themselves; that, consequently, there is no justice, or, if such there be, it is supreme folly, since one does violence to his own interests if he consults the advantage of others.
  2. What the philosopher here says, and the poet reaffirms in verse, “And just from unjust Nature cannot know” [Horace] must not for one moment be admitted. Man is, to be sure, an animal, but an animal of a superior kind, much farther removed from all other animals than the different kinds of animals are from one another; evidence on this point may be found in the many traits peculiar to the human species. But among the traits characteristic of man is an impelling desire for society, that is, for the social life not of any and every sort, but peaceful, and organized according to the measure of his intelligence, with those who are of his own kind; this social trend the Stoics called “sociableness.” Stated as a universal truth, therefore, the assertion that every animal is impelled by nature to seek only its own good cannot be conceded.
  3. This maintenance of the social order, which we have roughly sketched, and which is consonant with human intelligence, is the source of law properly so called. To this sphere of law belong the abstaining from that which is another’s; the restoration to another of anything of his which we may have, together with any gain which we may have received from it; the obligation to fulfill promises; the making good of a loss incurred through our fault; and the inflicting of penalties upon men according to their deserts. [“Prolegomena”]
  4. Now the Law of Nature is so unalterable, that it cannot be changed even by God himself. For although the power of God is infinite, yet there are some things, to which it does not extend. Because the things so expressed would have no true meaning, but imply a contradiction. Thus two and two must make four, nor is it possible to be otherwise; nor, again, can what is really evil not be evil. And this is Aristotle’s meaning, when he says, that some things are no sooner named, than we discover their evil nature. For as the substance of things in their nature and existence depends upon nothing but themselves; so there are qualities inseparably connected with their being and essence. Of this kind is the evil of certain actions, compared with the nature of a reasonable being. Therefore God himself suffers his actions to be judged by this rule. [1.1]

Just War Theory

As the Law of War is the title, by which this treatise is distinguished, the first inquiry, as it has been already observed, is, whether any war be just, and, in the next place, what constitutes the justice of that war. For, in this place, law signifies nothing more than what is just, and that, more in a negative than a positive sense; so that law is that, which is not unjust. Now anything is unjust, which is repugnant to the nature of society, established among rational creatures. Thus for instance, to deprive another of what belongs to him, merely for one’s own advantage, is repugnant to the law of nature. . . . [1.1]

The justifiable causes generally assigned for war are three: defense, reparation, and punishment. All of these are comprised in the declaration of Camillus against the Gauls, which lists all things for which it is right to defend, to recover, and the encroachment on which it is right to punish. [2.1]

Though most powers, when engaging in war, are desirous to color over their real motives with justifiable pretexts, yet some, totally disregarding such methods of vindication, seem able to give no better reason for their conduct, than what is told by the Roman Lawyers of a robber, who being asked, what right he had to a thing, which he had seized, replied, it was his own, because he had taken it into his possession? . . . Others make use of pretexts, which though plausible at first sight, will not bear the examination and test of moral rectitude, and, when stripped of their disguise, such pretexts will be found fraught with injustice. [2.22]

Though there may be circumstances, in which absolute justice will not condemn the sacrifice of lives in war, yet humanity will require that the greatest precaution should be used against involving the innocent in danger, except in cases of extreme urgency and utility. [3.11]

Now, driving off some of our cattle, or burning a few of our houses, can never be pleaded as a sufficient and justifiable motive for laying waste the whole of an enemy’s kingdom. Polybius saw this in its proper light, observing, that vengeance in war should not be carried to its extreme, nor extend any further than was necessary to make an aggressor atone justly for his offence. And it is upon these motives, and within these limits alone, that punishment can be inflicted. But except where prompted to it by motives of great utility, it is folly, and worse than folly, to needlessly hurt another. [3.13]

THOMAS HOBBES (1588–1679)

British philosopher who developed the notions of the state of nature and the social contract.


[T]he opinion that such spirits were incorporeal, or immaterial, could never enter into the mind of any man by nature; because, though men may put together words of contradictory signification, as spirit and incorporeal, yet they can never have the imagination of anything answering to them. And therefore, men that by their own meditation arrive to the acknowledgement of one infinite, omnipotent, and eternal God, choose rather to confess He is incomprehensible and above their understanding than to define His nature by spirit incorporeal, and then confess their definition to be unintelligible. Or if they give him such a title, it is not dogmatically, with intention to make the Divine Nature understood, but piously, to honor Him with attributes of significations as remote as they can from the grossness of bodies visible. [Leviathan, 12.7]

State of Nature

Hereby it is manifest, that during the time men live without a common power to keep them all in awe, they are in that condition which is called war; and such a war as is of every man against every man. For war consists not in battle only, or the act of fighting, but [also] in a tract of time, wherein the will to contend by battle is sufficiently known; and therefore the notion of time is to be considered in the nature of war, as it is in the nature of weather. For as the nature of foul weather lies not in a shower or two of rain, but in an inclination thereto of many days together; so the nature of war consists not in actual fighting, but in the known disposition thereto, during all the time there is no assurance to the contrary. All other time is peace.

Whatever therefore is consequent to a time of war, where every man is enemy to every man, the same is consequent to the time wherein men live without other security, than what their own strength and their own invention shall furnish them withal. In such condition, there is no place for industry, because the fruit thereof is uncertain; and consequently no culture of the earth, no navigation, nor use of the commodities that may be imported by sea; no commodious building, no instruments of moving and removing such things as require much force; no knowledge of the face of the earth, no account of time, no arts, no letters, no society; and which is worst of all, continual fear and danger of violent death; and the life of man, solitary, poor, nasty, brutish, and short. . . .

To this war of every man against every man, this also is consequent, that nothing can be unjust. The notions of right and wrong, justice and injustice have there no place. Where there is no common power, there is no law; where no law, no injustice. Force and fraud are in war the two cardinal virtues. Justice and injustice are none of the [instinctive] faculties, neither of the body nor mind. [Leviathan, 13]

Laws of Nature

The right of nature, which writers commonly call jus naturale, is the liberty each man has to use his own power as he will himself, for the preservation of his own nature (that is to say, of his own life, and consequently of doing anything which, in his own judgment and reason, he shall conceive to be the aptest means thereunto).

By liberty is understood, according to the proper signification of the word, the absence of external impediments; which impediments may often take away part of a man’s power to do what he would, but cannot hinder him from using the power left him, according as his judgment and reason shall dictate to him.

A Law of Nature (lex naturalis) is a precept, or general rule, found out by reason, by which a man is forbidden to do that which is destructive of his life, or takes away the means of preserving the same; and to omit that by which he thinks it may be best preserved. For though they that speak of this subject use to confound jus, and lex, right and law; yet they ought to be distinguished. Because, right consists in the liberty to do or to forbear, whereas law determines and binds to one of them, so that law and right differ as much as obligation and liberty, which in one and the same matter are inconsistent.

And because the condition of man (as has been declared in the precedent chapter) is a condition of war of everyone against everyone, in which case everyone is governed by his own reason (and there is nothing he can make use of that may not be a help to him in preserving his life against his enemies), it follows that in such a condition, every man has a right to everything, even to one another’s body. And therefore, as long as this natural right of every man to everything endures, there can be no security to any man (how strong or wise soever he be) of living out the time which nature ordinarily allows men to live. And consequently it is a precept, or general rule of reason, That every man ought to endeavor peace as far as he has hope of obtaining it; and when he cannot obtain it, that he may seek and use all helps and advantages of war; the first branch of which rule contains the first and fundamental Law of Nature, which is, To seek peace and follow it; the second, the sum of the right of nature, which is, By all means we can, to defend ourselves.

From this fundamental Law of Nature, by which men are commanded to endeavor peace, is derived this second Law, That a man be willing, when others are so too (as far-forth as for peace and defense of himself he shall think it necessary), to lay down this right to all things; and be contented with so much liberty against other men, as he would allow other men against himself. For so long as every man holds this right of doing anything he likes, [then] so long are all men in the condition of war. But if other men will not lay down their right as well as he, then there is no reason for anyone to divest himself of his. . . .

From that Law of Nature, by which we are obliged to transfer to another such rights as being retained hinder the peace of mankind, there follows a third, which is this: That men perform their covenants made, without which, covenants are in vain, and but empty words. And the right of all men to all things remaining, we are still in the condition of war.

And in this Law of Nature consists the fountain and original of justice. For where no covenant has preceded, there has no right been transferred, and every man has right to everything, and consequently no action can be unjust. But when a covenant is made, then to break it is unjust. And the definition of injustice is no other than the not performance of covenant. And whatever is not unjust, is just. [Leviathan, 14, 15]

Need for Government

For the laws of nature, as justice, equity, modesty, mercy, and, in sum, doing to others as we would be done to, of themselves, without the terror of some power to cause them to be observed, are contrary to our natural passions, that carry us to partiality, pride, revenge, and the like. And covenants, without the sword, are but words and of no strength to secure a man at all. Therefore, notwithstanding the laws of nature (which every one hath then kept, when he has the will to keep them, when he can do it safely), if there be no power erected, or not great enough for our security, every man will and may lawfully rely on his own strength and art for caution against all other men. [Leviathan, 17]

RENÉ DESCARTES (1596–1650)

French rationalist philosopher who developed a method of scientific investigation and argued that all knowledge is derived from the truth of one’s existence.

Method of Investigation

So, instead of the great number of precepts [of method] of which Logic is composed, I believed that I should find the four which I shall state quite sufficient, provided that I adhered to a firm and constant resolve never on any single occasion to fail in their observance.

The first of these was to accept nothing as true which I did not clearly recognize to be so; that is to say, carefully to avoid precipitation and prejudice in judgments, and to accept in them nothing more than what was presented to my mind so clearly and distinctly that I could have no occasion to doubt it.

The second was to divide up each of the difficulties which I examined into as many parts as possible, and as seemed requisite in order that it might be resolved in the best manner possible.

The third was to carry on my reflections in due order, commencing with objects that were the most simple and easy to understand, in order to rise little by little, or by degrees, to knowledge of the most complex, assuming an order, even if a fictitious one, among those which do not follow a natural sequence relatively to one another.

The last was in all cases to make enumerations so complete and reviews so general that I should be certain of having omitted nothing. [Discourse on the Method]

Systematic Doubt

It is now some years since I detected how many were the false beliefs that I had from my earliest youth admitted as true, and how doubtful was everything I had since constructed on this basis. And from that time I was convinced that I must once for all seriously undertake to rid myself of all the opinions which I had formerly accepted, and commence to build anew from the foundation, if I wanted to establish any firm and permanent structure in the sciences. . . . Now for this object it is not necessary that I should show that all of these are false — I will perhaps never arrive at this end. But inasmuch as reason already persuades me that I ought no less carefully to withhold my assent from matters which are not entirely certain and indubitable than from those which appear to me evidently to be false, if I am able to find in each one some reason to doubt, this will suffice to justify my rejecting the whole. And for that end it will not be requisite that I should examine each in particular, which would be an endless undertaking; for owing to the fact that the destruction of the foundations of necessity brings with it the downfall of the rest of the edifice, I will only in the first place attack those principles upon which all my former opinions rested.

All that up to the present time I have accepted as most true and certain I have learned either from the senses or through the senses; but it is sometimes proved to me that these senses are deceptive, and it is wiser not to trust entirely to anything by which we have once been deceived. . . .

Nevertheless I have long had fixed in my mind the belief that an all-powerful God existed by whom I have been created such as I am. But how do I know that he has not brought it to pass that there is no earth, no heaven, no extended body, no magnitude, no place, and that nevertheless [I possess the perceptions of all these things and that] they seem to me to exist just exactly as I now see them? And, besides, as I sometimes imagine that others deceive themselves in the things which they think they know best, how do I know that I am not deceived every time that I add two and three, or count the sides of a square, or judge of things yet simpler, if anything simpler can be imagined? . . .

I will then suppose, not that God who is supremely good and the fountain of truth, but some evil genius not less powerful than deceitful, has employed his whole energies in deceiving me. I will consider that the heavens, the earth, colors, figures, sound, and all other external things are nothing but the illusions and dreams of which this genius has availed himself in order to lay traps for my credulity. I will consider myself as having no hands, no eyes, no flesh, no blood, nor any senses, yet falsely believing myself to possess all these things. I will remain obstinately attached to this idea, and if by this means it is not in my power to arrive at the knowledge of any truth, I may at least do what is in my power [that is, suspend my judgment], and with firm purpose avoid giving credence to any false thing, or being imposed upon by this arch deceiver, however powerful and deceptive he may be. But this task is a laborious one, and insensibly a certain lethargy leads me into the course of my ordinary life. And just as a captive who in sleep enjoys an imaginary liberty, when he begins to suspect that his liberty is but a dream, fears to awaken, and conspires with these agreeable illusions that the deception may be prolonged, so insensibly of my own accord I fall back into my former opinions, and I dread awakening from this slumber, lest the laborious wakefulness which would follow the tranquility of this calmness should have to be spent not in daylight, but in the excessive darkness of the difficulties which have just been discussed. [Meditations 1]

One Indubitable Truth: I Exist

I suppose, then, that all the things that I see are false; I persuade myself that nothing has ever existed of all that my fallacious memory represents to me. I consider that I possess no senses; I imagine that body, figure, extension, movement and place are but the fictions of my mind. What, then, can be distinguished as true? Perhaps nothing at all, unless that there is nothing in the world that is certain.

But how can I know there is not something different from those things that I have just considered, of which one cannot have the slightest doubt? Is there not some God, or some other being by whatever name we call it, who puts these reflections into my mind? That is not necessary, for is it not possible that I am capable of producing them myself? I myself, am I not at least something? But I have already denied that I had senses and body. Yet I hesitate, for what follows from that? Am I so dependent on body and senses that I cannot exist without these? But I was persuaded that there was nothing in all the world, that there was no heaven, no earth, that there were no minds, nor any bodies: was I not then likewise persuaded that I did not exist? Not at all; of a surety I myself did exist since I persuaded myself of something [or merely because I thought of something]. But there is some deceiver or other, very powerful and very cunning, who ever employs his ingenuity in deceiving me. Then without doubt I exist also if he deceives me, and let him deceive me as much as he will, he can never cause me to be nothing so long as I think that I am something. So that after having reflected well and carefully examined all things, we must come to the definite conclusion that this proposition: I am, I exist, is necessarily true each time that I pronounce it, or that I mentally conceive it. . . .

But what then am I? A thing which thinks. What is a thing which thinks? It is a thing which doubts, understands, [conceives], affirms, denies, wills, refuses, which also imagines and feels. Certainly it is no small matter if all these things pertain to my nature. But why should they not so pertain? Am I not that being who now doubts nearly everything, who nevertheless understands certain things, who affirms that one only is true, who denies all the others, who desires to know more, is averse from being deceived, who imagines many things, sometimes indeed despite his will, and who perceives many likewise, as by the intervention of the bodily organs? [Meditations 2]

Mind and Body

In the next place, I attentively examined what I was. I observed that I could suppose that I had no body, and that there was no world, nor any place in which I might be. But I could not therefore sup­pose that I was not. On the contrary, from the very circumstance that I thought to doubt the truth of other things, it most clearly and certainly followed that I was. On the other hand, if I had only ceased to think, although all the other objects which I had ever imagined had been in reality existent, I would have had no reason to believe that I existed. I concluded from this that I was a substance whose whole essence or nature consists only in thinking, and which, that it may exist, has need of no place, nor is dependent on any material thing. Thus the “I” (that is to say, the mind by which I am what I am) is wholly dis­tinct from the body. It is even more easily known than the [body], and is such that even if the [body] did not exist, [my mind] would still continue to be all that it is.

I had expounded all these matters with sufficient detail in the treatise which I formerly thought of publishing. And after these, I had shown what must be the fabric of the nerves and muscles of the human body to give the animal spirits contained in it the power to move the limbs. We see this, for example, when heads shortly after they have been cut off still move and bite the earth, although no longer animated. . . .

Nor will this appear at all strange to those who are acquainted with the variety of movements performed by the different automata, or moving machines created by human engineering, and that with help of but few pieces compared with the great multitude of bones, muscles, nerves, arteries, veins, and other parts that are found in the body of each animal. Such persons will look upon this body as a machine made by the hands of God, which is incomparably better arranged, and adequate to movements more admirable than is any machine of human invention. [Discourse on the Method, 4]

It is likewise necessary to know that although the soul is joined to the whole body, there is yet in that a certain part in which it exercises its functions more particularly than in all the others. And it is usually believed that this part is the brain, or possibly the heart. It is believed to be the brain because it is with it that the organs of sense are connected. And it is believed to be the heart because it is apparently in it that we experience the passions. But, in examining the matter with care, it seems as though I had clearly ascertained that the part of the body in which the soul exercises its functions immediately is in nowise the heart, nor the whole of the brain. Instead, it is merely the most inward of all its parts, namely, a certain very small gland which is situated in the middle of its substance and so suspended above the duct whereby the animal spirits in its anterior cavities have communication with those in the posterior. It is such that the slightest movements which take place in it may alter very greatly the course of these spirits. And, reciprocally, the smallest changes which occur in the course of the spirits may do much to change the movements of this gland. [The Passions of the Soul, 1:31]


French rationalist philosopher who developed the theory of occasionalism and argued that we see all things through God.

Sensory Experience: Vision through God

We have examined in the preceding chapters four different manners in which the human mind may see external objects, and these do not appear probable to us. There only remains the fifth, which alone appears agreeable to reason and is the most proper, which is the dependence that spirits have on God in all their thoughts.

In order to understand it correctly, we must remember what has been said in the preceding chapter, that it is absolutely necessary that God should have in himself the ideas of all the beings he has created, since otherwise he could not have produced them. And, thus, he sees all those beings by considering the perfections which he includes in himself, and to which all beings are related. Moreover, it is necessary to know that God is very strictly united to our souls by his presence, so that we may say that he is the place of spirits, just as space is the place of bodies. These two things being supposed, it is certain that the mind may see what there is in God, which represents created beings, since that is very spiritual, very intelligible, and most present to the mind. Thus the mind may see in God the works of God, supposing God be willing to disclose to our minds what there is in God which represents those works. These are the reasons which seem to prove that he wills rather than creates an infinite number of ideas in every mind.

First, although we do not absolutely deny that God was able to produce an infinitely infinite number of beings who represent objects with every mind he creates, yet we ought not to believe that he does so. For it is not only compatible with reason, but it also appears by the economy of nature, that God never does by very difficult means what may be done by a plain and easy way. God does nothing in vain and without reason. His wisdom and his power are not exhibited by doing little things by difficult means. That is repugnant to reason, and shows a limited knowledge. On the contrary, his greatness is seen by doing great things by plain easy means. [Search after Truth, 3.2.6]

Motor Activity: Occasionalism

Now it appears most certain to me, that the will of spirits is not capable of moving the smallest body in the world. For it is evident there is no necessary connection between the will we have of moving our arms, and the motion of them. It is true, they are moved when we please, and by that means we are the natural cause of their motion. But natural causes are not true causes; they are only occasional ones, which act merely through the power and efficacy of God, as I have already explained.

For how can we move our arms? To move them we must have animal spirits, and convey them by certain nerves, into such and such muscles to swell and contract them. For by this means the arms move. Or according to the opinion of some, we do not know yet how it is performed. And we see that people who do not even know they have spirits, nerves, and muscles to move their arms, yet move them with as much art and facility as those that understand anatomy best. It is then granted, that people will the motion of their arms, but it is only God that can and knows how to remove them. If a person cannot throw down a tower, at least he knows well what must be done in order to it. But there is no person that knows so much as what he must do to move one of his fingers by the help of his animal spirits. How then can people move their arms? These things appear evident to me, and to all those that will think of them, though perhaps they may be incomprehensible to such as will not consider them. [Search after Truth, 6.2.3]

Argument for Occasionalism

It is evident that all bodies, both great and small, have no power of removing themselves: a mountain, an house, a stone, a grain of sand. In short, the least or biggest bodies we can conceive, have no power of removing themselves. We have only two sorts of ideas, that of bodies, and that of spirits. Since we ought to speak only of those things which we conceive, we should reason according to these two ideas. Since therefore the idea we have of all bodies shows us that they cannot move themselves, it must be concluded that they are moved by spirits only. But when we examine the idea we have of all finite minds, we do not see the necessary connection between their wills and the motion of any body whatever it may be. On the contrary, we see that there is none, nor can there be any. From this we ought to conclude (if we will argue according to our knowledge) that as no body is able to move itself, so there is no created spirit that can be the true or principal cause of the motion of any body whatever.

But when we think of the idea of God, of a being infinitely perfect, and consequently almighty, we know that there is such a connection between his will, and the motion of all bodies. It is impossible to conceive that he should will the motion of a body, and that would not be moved. Thus, if we speak things as we conceive them (and not as we feel them), we must say that only his will can move bodies. The moving force of bodies, therefore, is not in the bodies which move, since this power of motion is nothing else but the will of God. [Search after Truth, 6.2.3]

God and Evil

God acts only in accordance with what he is, only in a way which bears the character of his attributes, only for the sake of the glory which he finds in the relation which his work and his ways jointly have to the perfections which he possesses and in the possession of which he glories. It is the grandeur of this relation that God considers in framing his designs; for this is the principle: God can act only in accordance with what he is, and can will absolutely and directly only for the sake of his glory. If the defects of the universe, wherein we dwell, diminish this relation, the simplicity, fruitfulness and wisdom of its ways and laws which God follows increase it all the more. A world more perfect, but produced in ways less fruitful and less simple, would not bear to the same extent as ours the character of the divine attributes. This is why the world is full of infidels, monstrosities, disorder of all kinds. God could convert all men, render impossible all disorders; but in order to accomplish this he must not disturb the simplicity and uniformity of his action, for he is bound to honor it by the wisdom of his ways as well as by the perfection of his creatures. He does not permit monstrosities, he makes them. But he makes them only in order not to change anything in his procedure and only out of respect for the generality of his ways, only in order to follow exactly the natural laws which he has established and which nevertheless he has not established because of the monstrous effects which they are wont to produce, but for effects more worthy of his wisdom and loving kindness. That is why one can say that he permits them, though none but he is responsible for their production. For he wills them only indirectly, only because they are a natural consequence of his laws. [Dialogues on Metaphysics and Religion, 9.11]


Jewish rationalist philosopher who argued that God (in a non-personal sense) is the single substance of the universe.

Subtance Monism

Prop. XIV. Besides God no substance can be granted or conceived.

Proof. As God is a being absolutely infinite, of whom no attribute that expresses the essence of substance can be denied (by Def. vi.), and he necessarily exists (by Prop. xi.) ; if any substance besides God were granted, it would have to be explained by some attribute of God, and thus two substances with the same attribute would exist, which (by Prop. v.) is absurd ; therefore, besides God no substance can be granted, or, consequently, be conceived. If it could be conceived, it would necessarily have to be conceived as existent ; but this (by the first part of this proof) is absurd. Therefore, besides God no substance can be granted or conceived. Q.E.D.

Corollary I.—Clearly, therefore : 1. God is one, that is (by Def. vi.) only one substance can be granted in the universe, and that substance is absolutely infinite, as we have already indicated (in the note to Prop. x.).

Corollary II.—It follows : 2. That extension and thought are either attributes of God or (by Ax. i.) accidents (affectiones) of the attributes of God.

Prop. XV. Whatsoever is, is in God, and without God nothing can be, or be conceived.

Proof.—Besides God, no substance is granted or can be conceived (by Prop. xiv.), that is (by Def. iii.) nothing which is in itself and is conceived through itself. But modes (by Def. v.) can neither be, nor be conceived without substance ; wherefore they can only be in the divine nature, and can only through it be conceived. But substances and modes form the sum total of existence (by Ax. i.), therefore, without God nothing can be, or be conceived. Q.E.D.

Mind-body Parallelism

The order and connection of ideas is the same as the order and connection of things. . . . Hence God’s power of thinking is equal to his realized power of action–that is, whatsoever follows from the infinite nature of God in the world of extension, follows without exception in the same order and connection from the idea of God in the world of thought.

Before going any further, I wish to recall to mind what has been pointed out above–namely, that whatsoever can be perceived by the infinite intellect as constituting the essence of substance, belongs altogether only to one substance: consequently, substance thinking and substance extended are one and the same substance, comprehended now through one attribute, now through the other. So also, a mode of extension and the idea of that mode are one and the same thing, though expressed in two ways. This truth seems to have been dimly recognized by those Jews who maintained that God, God’s intellect, and the things understood by God are identical.

A circle existing in nature and the idea of the existing circle, which is also in God, are one and the same thing, which is explained through different attributes. Therefore, whether we conceive nature under the attribute of Extension, or under the attribute of Thought, or under any other attribute, we shall find one and the same order, or one and the same connection of causes, i.e., that the same things follow one another. [Ethics, 2:7]

Mind and body are one and the same thing, conceived first under the attribute of thought, secondly, under the attribute of extension. Thus it follows that the order or concatenation of things is identical, whether nature be conceived under the one attribute or the other; consequently the order of states of activity and passivity in our body is simultaneous in nature with the order of states of activity and passivity in the mind. . . . Nevertheless, though such is the case, and though there be no further room for doubt, I can scarcely believe, until the fact is proved by experience, that men can be induced to consider the question calmly and fairly, so firmly are they convinced that it is merely at the bidding of the mind, that the body is set in motion or at rest, or performs a variety of actions depending solely on the mind’s will or the exercise of thought. [Ethics, 3.2]

Determinism in God’s Nature

Prop. XXXII. Will cannot be called a free cause, but only a necessary cause.

Proof. Will is only a particular mode of thinking, like intellect ; therefore (by Prop. xxviii.) no volition can exist, nor be conditioned to act, unless it be conditioned by some cause other than itself, which cause is conditioned by a third cause, and so on to infinity. But if will be supposed infinite, it must also be conditioned to exist and act by God, not by virtue of his being substance absolutely infinite, but by virtue of his possessing an attribute which expresses the infinite and eternal essence of thought (by Prop. xxiii.). Thus, however it be conceived, whether as finite or infinite, it requires a cause by which it should be conditioned to exist and act. Thus (Def. vii.) it cannot be called a free cause, but only a necessary or constrained cause. Q.E.D.

Corollary I.—Hence it follows, first, that God does not act according to freedom of the will. [Ethics, 1.32]

It is accepted as certain, that God himself directs all things to a definite goal (for it is said that God made all things for man, and so that man might worship God). I will, therefore, consider this opinion. . . [and] point out its falsity. . . . There is no need to show at length that nature has no particular goal in view, and that final causes are mere human figments. This, I think, is already evident enough . . . [from the fact] that everything in nature proceeds from a sort of necessity, and with the utmost perfection. However, I will add a few remarks, in order to overthrow this doctrine of a final cause utterly. That which is really a cause it considers as an effect, and vice versa: it makes that which is by nature first to be last, and that which is highest and most perfect to be most imperfect. . . . [T]hat effect is most perfect which is produced immediately by God. The effect which requires for its production several intermediate causes is, in that respect, more imperfect. But if those things which were made immediately by God were made to enable him to attain his end, then the things which come after, for the sake of which the first were made, are necessarily the most excellent of all. [Ethics, 1, Appendix]

Determinism and Bondage in Human Nature

Nothing in nature is contingent, but all things are determined to exist and operate in a particular manner by the necessity of the divine nature. [Ethics, 1:29]

Thus an infant believes that of its own free will it desires milk, an angry child believes that it freely desires vengeance, a timid child believes that it freely desires to run away. Further, a drunken man believes that he utters from the free decision of his mind words which, when he is sober, he would willingly have withheld. Thus, too, a delirious man, a garrulous woman, a child, and others of like complexion, believe that they speak from the free decision of their mind, when they are in reality unable to restrain their impulse to talk.

Experience teaches us no less clearly than reason, that men believe themselves to be free, simply because they are conscious of their actions, and unconscious of the causes whereby those actions are determined…. [Ethics, 3:2]

Human infirmity in moderating and checking the emotions I name bondage: for, when a man is a prey to his emotions, he is not his own master, but lies at the mercy of fortune: so much so, that he is often compelled, while seeing that which is better for him, to follow that which is worse. [Ethics, 4: Preface]

I think I have now shown the reason, why men are moved by opinion more readily than by true reason, why it is that the true knowledge of good and evil stirs up conflicts in the soul, and often yields to every kind of passion. This state of things gave rise to the exclamation of [Ovid] the poet: “The better path I gaze at and approve, the worse I follow.” Ecclesiastes seems to have had the same thought in his mind, when he says, “He who increases knowledge increases sorrow.”

I have not written the above with the object of drawing the conclusion, that ignorance is more excellent than knowledge, or that a wise man is on a par with a fool in controlling his emotions. However, I wrote so because it is necessary to know the power and the infirmity of our nature, before we can determine what reason can do in restraining the emotions, and what is beyond her power. [Ethics, 4.17]

Free Speech

I have thus shown (1) That it is impossible to deprive men of the liberty of saying what they think. (2) That such liberty can be conceded to every man without injury to the rights and authority of the sovereign power, and that every man may retain it without injury to such rights, provided that he does not presume upon it to the extent of introducing any new rights into the state, or acting in any way contrary, to the existing laws. (3) That every man may enjoy this liberty without detriment to the public peace, and that no inconveniences arise therefrom which cannot easily be checked. (4) That every man may enjoy it without injury to his allegiance. (5) That laws dealing with speculative problems are entirely useless. (6) Lastly, that not only may such liberty be granted without prejudice to the public peace, to loyalty, and to the rights of rulers, but that it is even necessary, for their preservation. For when people try to take it away, and bring to trial, not only the acts which alone are capable of offending, but also the opinions of mankind, they only succeed in surrounding their victims with an appearance of martyrdom, and raise feelings of pity and revenge rather than of terror. [Theological-Political Treatise, 20]


German rationalist philosopher who developed the theory of monads and argued that this is the best possible world that God could create.

God Creates in the most Perfect Manner

The conception of God which is the most common and the most full of meaning is expressed well enough in the words: God is an absolutely perfect being. The implications, however, of these words fail to receive sufficient consideration. For instance, there are many different kinds of perfection, all of which God possesses, and each one of them pertains to him in the highest degree.

We must also know what perfection is. One thing which can surely be affirmed about it is that those forms or natures which are not susceptible of it to the highest degree, say the nature of numbers or of figures, do not permit of perfection. This is because the number which is the greatest of all (that is, the sum of all the numbers), and likewise the greatest of all figures, imply contradictions. The greatest knowledge, however, and omnipotence contain no impossibility. Consequently power and knowledge do admit of perfection, and in so far as they pertain to God they have no limits.

From this it follows that God who possesses supreme and infinite wisdom acts in the most perfect manner not only metaphysically, but also from the moral standpoint. And with respect to ourselves it can be said that the more we are enlightened and informed in regard to the works of God the more will we be disposed to find them excellent and conforming entirely to that which we might desire. [Discourse, 1]

Monads in an Infinitely Divisible Plenum

To admit a vacuum in nature is ascribing to God a very imperfect work. It is violating the grand principle of the necessity of a sufficient reason which many have talked of, without understanding its true meaning; as I have lately shown in proving, by that principle, that space is only an order of things, as time also is, and not at all an absolute being. To omit many other arguments against a vacuum and atoms, I shall here mention those which I ground upon God’s perfection, and upon the necessity of a sufficient reason. I lay it down as a principle, that every perfection which God could impart to things without derogating from their other perfections, has actually been imparted to them. Now let us fancy a space wholly empty. God could have placed some matter in it, without derogating in any respect from all other things. Therefore he has actually placed some matter in that space. Therefore, there is no space wholly empty. Therefore all is full. [Fourth Letter to Clarke]

Atoms of matter are contrary to reason, besides the fact that they also are composed of parts, since the invincible attachment of one part to another (granted that this could be reasonably conceived or supposed) would not destroy their diversity. It is only atoms of substance, that is to say unities which are real and absolutely without parts, which can be the sources of actions, and the absolute first principles of the composition of things, and as it were the ultimate elements into which substantial things can be analysed. They might be called metaphysical points, there is about them something vital and a kind of perception, and mathematical points are their points of view for expressing the universe. But when corporeal substances are contracted all their organs constitute to us but a physical point. Thus physical points are indivisible in appearance only: mathematical points are exact, but they are nothing but modalities. It is only metaphysical points, or points of substance (constituted by forms or souls), which are both exact and real; and without them there would be nothing real, since without true unities there would be no plurality. [“The New System”]

How Monads Form Things

  1. Substance is being, capable of action. It is simple or compound. Simple substance is that which has no parts. Compound substance is a collection of simple substances or monads. Monas is a Greek word which signifies unity, or that which is one. Compounds, or bodies, are multitudes; and simple substances, lives, souls, spirits are unities. And there must be simple substances everywhere, because without simple substances there would be no compounds; and consequently all nature is full of life.
  2. Monads, having no parts, cannot be formed or decomposed. They cannot begin or end naturally; and consequently last as long as the universe, which will indeed be changed but will not be destroyed. They cannot have shapes; otherwise they would have parts. And consequently a monad, in itself and at a given moment, could not be distinguished from another except by its internal qualities and actions, which can be nothing else than its perceptions (that is, representations of the compound, or of what is external, in the simple), and its appetites (that is, its tendencies from one perception to another), which are the principles of change. For the simplicity of substance does not prevent multiplicity of modifications, which must be found together in this same simple substance, and must consist in the variety of relations to things which are external. Just as in a centre or point, altogether simple as it is, there is found an infinity of angles formed by lines which there meet.
  3. All of nature is a plenum. There are everywhere simple substances, separated in reality from each other by activities of their own which continually change their relations ; and each simple substance, or monad, which forms the centre of a compound substance (as, for example, of an animal) and the principle of its unity, is surrounded by a mass composed of an infinity of other monads, which constitute the body proper of this central monad; and in accordance with the affections of this it represents, as a centre, the things which are outside of itself. And this body is organic, when it forms a sort of automaton or natural machine; which is a machine not only in its entirety, but also in its smallest perceptible parts. And as, because the world is a plenum, everything is connected and each body acts upon every other body, more or less according to the distance, and by reaction is itself affected thereby; it follows that each monad is a mirror, living or endowed with internal activity, representative according to its point of view of the universe, and as regulated as the universe itself. And perceptions in the monad spring one from the other, by the law of appetites or by the final causes of good and evil, which consist in visible, regulated or unregulated perceptions; just as the changes of bodies and external phenomena spring one from another, by the laws of efficient causes, that is, of movements. Thus there is perfect harmony between the perceptions of the monad and the movements of bodies, established at the beginning between the system of efficient causes and that of final causes. And in this consists the accord and physical union of the soul and body, although neither one can change the laws of the other. [“Principles of Nature and Grace,” 1-3]

Souls and Mind-Body Parallelism

  1. Each monad, with a particular body, makes a living substance. Thus there is not only life everywhere, provided with members or organs, but also there is an infinity of degrees in monads, some dominating more or less over the others. But when the monad has organs so adjusted that by means of them there is clearness and distinctness in the impressions which it receives and consequently in the perceptions which represent them (as, for example, when by means of the shape of the humors of the eyes, the rays of light are concentrated and act with more force). This can extend even to feeling, that is, even to a perception accompanied by memory, that is, one a certain echo of which remains a long time to make itself heard upon occasion. Such a living being is called an animal, as its monad is called a soul. When this soul is elevated to reason it is something more sublime and is reckoned among spirits, as will soon be explained. [“Principles of Nature and Grace,” 4]

You do not understand, you say, how I could prove that which I advanced concerning the communication or harmony of two substances so different as the soul and the body. It is true that I believe that I have found the means of doing so, and this is how I propose to satisfy you. Imagine two clocks or watches which agree perfectly. Now, this may take place in three ways. The first consists in a mutual influence; the second is to have a skillful workman attached to them who regulates them and keeps them always in accord; the third is to construct these two clocks with so much art and accuracy as to assure their future harmony. Put now the soul and the body in place of these two clocks; their accordance may be brought about by one of these three ways. The way of influence is that of common philosophy, but as we cannot conceive of material particles which may pass from one of these substances into the other, this view must be abandoned. The way of the continual assistance of the creator is that of the system of occasional causes; but I hold that this is to make a Deus ex Machina intervene in a natural and ordinary matter, in which, according to reason, he ought not to cooperate except in the way in winch he does in all other natural things. Thus there remains only my hypothesis; that is, the way of harmony. From the beginning God has made each of these two substances of such a nature that merely by following its own peculiar laws, received with its being, it nevertheless accords with the other, just as if there were a mutual influence or as if God always put his hand thereto in addition to his general cooperation. [“The New System,” Postscript, 1696]

Evil and the Best of All Possible Worlds

  1. Now as there are an infinity of possible universes in the ideas of God, and but only one of them can exist, there must be a sufficient reason for the choice of God which determines him to select one rather than another.
  2. And this reason is to be found only in the fitness or in the degree of perfection which these worlds possess, each possible thing having the right to claim existence in proportion to the perfection which it involves.
  3. This is the cause for the existence of the greatest good; namely, that the wisdom of God permits him to know it, his goodness causes him to choose it, and his power enables him to produce it.
  4. We can say also that God, the Architect, satisfies in all respects God the Law Giver, that therefore sins will bring their own penalty with them through the order of nature, and because of the very structure of things, mechanical though it is. And in the same way the good actions will attain their rewards in mechanical way through their relation to bodies, although this cannot and ought not always to take place without delay. [“Monadology”]

The best course is not always that one which tends towards avoiding evil, since it is possible that the evil may be accompanied by a greater good. For example, the general of an army will prefer a great victory with a slight wound to a state of affairs without wound and without victory. I have proved this in further detail in this work [i.e., in the Theodicy] by pointing out, through instances taken from mathematics and elsewhere, that an imperfection in the part may be required for a greater perfection in the whole. I have followed therein the opinion of St. Augustine, who said a hundred times that God permitted evil in order to derive from it a good, that is to say, a greater good; and Thomas Aquinas says (in libr. 2, Sent. Dist. 32, qu. 1, art. 1) that the permission of evil tends towards the good of the universe. I have shown that among older writers the fall of Adam was termed felix culpa, a fortunate sin, because it had been expiated with immense benefit by the incarnation of the Son of God: for he gave to the universe something more noble than anything there would otherwise have been amongst created beings. For the better understanding of the matter I added, following the example of many good authors, that it was consistent with order and the general good for God to grant to certain of his creatures the opportunity to exercise their freedom, even when he foresaw that they would turn to evil: for God could easily correct the evil, and it was not fitting that in order to prevent sin he should always act in an extraordinary way. It will therefore sufficiently refute the objection to show that a world with evil may be better than a world without evil. But I have gone still further in the work, and have even shown that this universe must be indeed better than every other possible universe. [Theodicy, Summary]

JOHN LOCKE (1632–1704)

British empiricist philosopher who denied innate ideas and argued that knowledge come from experience.

No Innate Ideas

It is an established opinion among some people that there are in the understanding certain innate principles . . . as it were stamped upon the mind of man, which the soul receives in its very first being and brings into the world with it. It would be sufficient to convince unprejudiced readers of the falseness of this supposition, if I should only show . . . how people, barely by the use of their natural faculties, may attain to all the knowledge they have, without the help of any innate impressions, and may arrive at certainty without any such original notions or principles. For I imagine anyone will easily grant that it would be impertinent to suppose [that] the ideas of colors [are] innate in a creature to whom God has given sight, and a power to receive them by the eyes from external objects. And no less unreasonable would it be to attribute several truths to the impressions of nature, and innate characters, when we may observe in ourselves faculties fit to attain as easy and certain knowledge of them as if they were originally imprinted on the mind.

For, first, it is evident, that all children and idiots have not the least apprehension or thought of them. And the want of that is enough to destroy that universal assent which must needs be the necessary concomitant of all innate truths: it seeming to me near a contradiction to say, that there are truths imprinted on the soul, which it perceives or understands not: imprinting, if it signify anything, being nothing else but the making certain truths to be perceived. For to imprint anything on the mind without the mind’s perceiving it, seems to me hardly intelligible. If therefore children and idiots have souls, have minds, with those impressions upon them, they must unavoidably perceive them, and necessarily know and assent to these truths. Which since they do not, it is evident that there are no such impressions. For if they are not notions naturally imprinted, how can they be innate? and if they are notions imprinted, how can they be unknown? To say a notion is imprinted on the mind, and yet at the same time to say, that the mind is ignorant of it, and never yet took notice of it, is to make this impression nothing.

If by knowing and assenting to them “when we come to the use of reason,” be meant that this is the time when they come to be taken notice of by the mind; and that as soon as children come to the use of reason, they come also to know and assent to these maxims, this also is false and frivolous. First, it is false because it is evident [that] these maxims are not in the mind so early as the use of reason. And therefore the coming to the use of reason is falsely assigned as the time of their discovery. How many instances of the use of reason may we observe in children, a long time before they have any knowledge of this maxim, “That it is impossible for the same thing to be and not to be?” And a great part of illiterate people and savages pass many years, even of their rational age, without ever thinking on this and the like general propositions. [Essay, 1.2.1, 5, 12]

Sensation and Reflection

Let us then suppose the mind to be, as we say, white paper, void of all characters, without any ideas: – How comes it to be furnished? Whence comes it by that vast store which the busy and boundless fancy of man has painted on it with an almost endless variety? Whence has it all the materials of reason and knowledge? To this I answer, in one word, from experience. In that all our knowledge is founded; and from that it ultimately derives itself. Our observation employed either, about external sensible objects, or about the internal operations of our minds perceived and reflected on by ourselves, is that which supplies our understandings with all the materials of thinking. These two are the fountains of knowledge, from whence all the ideas we have, or can naturally have, do spring. [Essay, 2.1.2-4]

First, our Senses, conversant about particular sensible objects, do convey into the mind several distinct perceptions of things, according to those various ways wherein those objects do affect them. And thus we come by those ideas we have of yellow, white, heat, cold, soft, hard, bitter, sweet, and all those which we call sensible qualities; which when I say the senses convey into the mind, I mean, they from external objects convey into the mind what produces there those perceptions. This great source of most of the ideas we have, depending wholly upon our senses, and derived by them to the understanding, I call sensation.

Secondly, the other fountain from which experience furnishes the understanding with ideas is, – the perception of the operations of our own mind within us, as it is employed about the ideas it has got; – which operations, when the soul comes to reflect on and consider, do furnish the understanding with another set of ideas, which could not be had from things without. And such are perception, thinking, doubting, believing, reasoning, knowing, willing, and all the different actings of our own minds; – which we being conscious of, and observing in ourselves, do from these receive into our understandings as distinct ideas as we do from bodies affecting our senses. This source of ideas every man has wholly in himself; and though it be not sense, as having nothing to do with external objects, yet it is very like it, and might properly enough be called internal sense. But as I call the other sensation, so I Call this reflection, the ideas it affords being such only as the mind gets by reflecting on its own operations within itself. By reflection then, in the following part of this discourse, I would be understood to mean, that notice which the mind takes of its own operations, and the manner of them, by reason whereof there come to be ideas of these operations in the understanding. These two, I say, viz. external material things, as the objects of sensation, and the operations of our own minds within, as the objects of reflection, are to me the only originals from whence all our ideas take their beginnings. The term operations here I use in a large sense, as comprehending not barely the actions of the mind about its ideas, but some sort of passions arising sometimes from them, such as is the satisfaction or uneasiness arising from any thought. [Essay, 2.1.2-4]

Simple and Complex Ideas

  1. Uncompounded Appearances. The better to understand the nature, manner, and extent of our knowledge, one thing is carefully to be observed concerning the ideas we have; and that is, that some of them are simple and some complex.

Though the qualities that affect our senses are, in the things themselves, so united and blended, that there is no separation, no distance between them; yet it is plain, the ideas they produce in the mind enter by the senses simple and unmixed. [2.2]

  1. Division of Simple Ideas. The better to conceive the ideas we receive from sensation, it may not be amiss for us to consider them, in reference to the different ways whereby they make their approaches to our minds, and make themselves perceivable by us.

First, then, There are some which come into our minds by one sense only.

Secondly, There are others that convey themselves into the mind by more senses than one.

Thirdly, Others that are had from reflection only.

Fourthly, There are some that make themselves way, and are suggested to the mind by all the ways of sensation and reflection.

We shall consider them apart under these several heads.

  1. Few Simple Ideas Have Names. I think it will be needless to enumerate all the particular simple ideas belonging to each sense. Nor indeed is it possible if we would; there being a great many more of them belonging to most of the senses than we have names for. The variety of smells, which are as many almost, if not more, than species of bodies in the world, do most of them want names. Sweet and stinking commonly serve our turn for these ideas, which in effect is little more than to call them pleasing or displeasing; though the smell of a rose and violet, both sweet, are certainly very distinct ideas. Nor are the different tastes, that by our palates we receive ideas of, much better provided with names. Sweet, bitter, sour, harsh, and salt are almost all the epithets we have to denominate that numberless variety of relishes, which are to be found distinct, not only in almost every sort of creatures, but in the different parts of the same plant, fruit, or animal. The same may be said of colors and sounds. [Essay, 2.3]
  2. Made By The Mind Out Of Simple Ones. We have hitherto considered those ideas, in the reception whereof the mind is only passive, which are those simple ones received from sensation and reflection before mentioned, whereof the mind cannot make one to itself, nor have any idea which does not wholly consist of them. But as the mind is wholly passive in the reception of all its simple ideas, so it exerts several acts of its own, whereby out of its simple ideas, as the materials and foundations of the rest, the others are framed. The acts of the mind, wherein it exerts its power over its simple ideas, are chiefly these three: (1) Combining several simple ideas into one compound one; and thus all complex ideas are made. (2) The second is bringing two ideas, whether simple or complex, together, and setting them by one another, so as to take a view of them at once, without uniting them into one; by which way it gets all its ideas of relations. (3) The third is separating them from all other ideas that accompany them in their real existence: this is called abstraction: and thus all its general ideas are made. This shows man’s power, and its ways of operation, to be much the same in the material and intellectual world. [Essay, 2.12]

Primary and Secondary Qualities

Qualities thus considered in bodies are, First, such as are utterly inseparable from the body, in what state soever it be; and such as in all the alterations and changes it suffers, all the force can be used upon it, it constantly keeps; and such as sense constantly finds in every particle of matter which has bulk enough to be perceived; and the mind finds inseparable from every particle of matter, though less than to make itself singly be perceived by our senses: v.g. Take a grain of wheat, divide it into two parts; each part has still solidity, extension, figure, and mobility: divide it again, and it retains still the same qualities; and so divide it on, till the parts become insensible; they must retain still each of them all those qualities. For division (which is all that a mill, or pestle, or any other body, does upon another, in reducing it to insensible parts) can never take away either solidity, extension, figure, or mobility from any body, but only makes two or more distinct separate masses of matter, of that which was but one before; all which distinct masses, reckoned as so many distinct bodies, after division, make a certain number. These I call original or primary qualities of body, which I think we may observe to produce simple ideas in us, viz. solidity, extension, figure, motion or rest, and number.

            Secondly, such qualities which in truth are nothing in the objects themselves but power to produce various sensations in us by their primary qualities, i.e. by the bulk, figure, texture, and motion of their insensible parts, as colors, sounds, tastes, &c. These I call secondary qualities. To these might be added a third sort, which are allowed to be barely powers; though they are as much real qualities in the subject as those which I, to comply with the common way of speaking, call qualities, but for distinction, secondary qualities. For the power in fire to produce a new color, or consistency, in wax or clay, – by its primary qualities, is as much a quality in fire, as the power it has to produce in me a new idea or sensation of warmth or burning, which I felt not before, – by the same primary qualities, viz. the bulk, texture, and motion of its insensible parts. [Essay, 2.8.9-10]

Natural Rights

The state of nature has a law of nature to govern it, which obliges every one: and reason, which is that law, teaches all mankind, who will but consult it, that being all equal and independent, no one ought to harm another in his life, health, liberty, or possessions: for men being all the workmanship of one omnipotent, and infinitely wise maker; all the servants of one sovereign master, sent into the world by his order, and about his business; they are his property, whose workmanship they are, made to last during his, not one another’s pleasure: and being furnished with like faculties, sharing all in one community of nature, there cannot be supposed any such subordination among us, that may authorize us to destroy one another, as if we were made for one another’s uses, as the inferior ranks of creatures are for ours. Everyone, as he is bound to preserve himself, and not to quit his station willfully, so by the like reason, when his own preservation comes not in competition, ought he, as much as he can, to preserve the rest of mankind, and may not, unless it be to do justice on an offender, take away, or impair the life, or what tends to the preservation of the life, the liberty, health, limb, or goods of another.

And that all men may be restrained from invading others rights, and from doing hurt to one another, and the law of nature be observed, which wills the peace and preservation of all mankind, the execution of the law of nature is, in that state, put into every man’s hands, whereby every one has a right to punish the transgressors of that law to such a degree, as may hinder its violation: for the law of nature would, as all other laws that concern men in this world ‘be in vain, if there were no body that in the state of nature had a power to execute that law, and thereby preserve the innocent and restrain offenders. And if any one in the state of nature may punish another for any evil he has done, every one may do so: for in that state of perfect equality, where naturally there is no superiority or jurisdiction of one over another, what any may do in prosecution of that law, every one must needs have a right to do. [Second Treatise, 6, 7]

Overthrowing Government

The reason why men enter into society, is the preservation of their property; and the end why they chuse and authorize a legislative, is, that there may be laws made, and rules set, as guards and fences to the properties of all the members of the society, to limit the power, and moderate the dominion, of every part and member of the society: for since it can never be supposed to be the will of the society, that the legislative should have a power to destroy that which every one designs to secure, by entering into society, and for which the people submitted themselves to legislators of their own making; whenever the legislators endeavor to take away, and destroy the property of the people, or to reduce them to slavery under arbitrary power, they put themselves into a state of war with the people, who are thereupon absolved from any farther obedience, and are left to the common refuge, which God has provided for all men, against force and violence. Whensoever therefore the legislative shall transgress this fundamental rule of society; and either by ambition, fear, folly or corruption, endeavor to grasp themselves, or put into the hands of any other, an absolute power over the lives, liberties, and estates of the people; by this breach of trust they forfeit the power the people had put into their hands for quite contrary ends, and it devolves to the people, who have a right to resume their original liberty, and, by the establishment of a new legislative, (such as they shall think fit) provide for their own safety and security, which is the end for which they are in society. [Second Treatise, 222]


Irish empiricist philosopher who argued for the idealist position that there is no material world, and that all reality exists in the minds of spirits.

Matter does not Exist

  1. It is indeed an opinion strangely prevailing amongst men, that houses, mountains, rivers, and in a word all sensible objects, have an existence, natural or real, distinct from their being perceived by the understanding. But, with how great an assurance and acquiescence soever this principle may be entertained in the world, yet whoever shall find in his heart to call it in question may, if I mistake not, perceive it to involve a manifest contradiction. For, what are the fore-mentioned objects but the things we perceive by sense? and what do we perceive besides our own ideas or sensations? and is it not plainly repugnant that any one of these, or any combination of them, should exist unperceived? [Principles, 4]

Primary Qualities Depend on a Spectator’s Perception

  1. Some there are who make a distinction betwixt primary and secondary qualities. By the former they mean extension, figure, motion, rest, solidity or impenetrability, and number; by the latter they denote all other sensible qualities, as colors, sounds, tastes, and so forth. The ideas we have of these they acknowledge not to be the resemblances of anything existing without the mind, or unperceived, but they will have our ideas of the primary qualities to be patterns or images of things which exist without the mind, in an unthinking substance which they call Matter. By Matter, therefore, we are to understand an inert, senseless substance, in which extension, figure, and motion do actually subsist. But it is evident from what we have already shown, that extension, figure, and motion are only ideas existing in the mind, and that an idea can be like nothing but another idea, and that consequently neither they nor their archetypes can exist in an unperceiving substance. Hence, it is plain that that the very notion of what is called Matter or corporeal substance, involves a contradiction in it.
  2. They who assert that figure, motion, and the rest of the primary or original qualities do exist without the mind in unthinking substances, do at the same time acknowledge that colors, sounds, heat cold, and suchlike secondary qualities, do not- which they tell us are sensations existing in the mind alone, that depend on and are occasioned by the different size, texture, and motion of the minute particles of matter. This they take for an undoubted truth, which they can demonstrate beyond all exception. Now, if it be certain that those original qualities are inseparably united with the other sensible qualities, and not, even in thought, capable of being abstracted from them, it plainly follows that they exist only in the mind. But I desire any one to reflect and try whether he can, by any abstraction of thought, conceive the extension and motion of a body without all other sensible qualities. For my own part, I see evidently that it is not in my power to frame an idea of a body extended and moving, but I must withal give it some color or other sensible quality which is acknowledged to exist only in the mind. In short, extension, figure, and motion, abstracted from all other qualities, are inconceivable. Where therefore the other sensible qualities are, there must these be also, to wit, in the mind and nowhere else. [Principles, 9, 10]

Argument from Simplicity

  1. But, though we might possibly have all our sensations without them, yet perhaps it may be thought easier to conceive and explain the manner of their production, by supposing external bodies in their likeness rather than otherwise; and so it might be at least probable there are such things as bodies that excite their ideas in our minds. But neither can this be said; for, though we give the materialists their external bodies, they by their own confession are never the nearer knowing how our ideas are produced; since they own themselves unable to comprehend in what manner body can act upon spirit, or how it is possible it should imprint any idea in the mind. Hence it is evident the production of ideas or sensations in our minds can be no reason why we should suppose Matter or corporeal substances, since that is acknowledged to remain equally inexplicable with or without this supposition. If therefore it were possible for bodies to exist without the mind, yet to hold they do so, must needs be a very precarious opinion; since it is to suppose, without any reason at all, that God has created innumerable beings that are entirely useless, and serve to no manner of purpose. [Principles, 19]

No need for Matter as an Instrument

We indeed, who are beings of finite powers, are forced to make use of instruments. And the use of an instrument shows the agent to be limited by rules of another’s prescription, and that he cannot obtain his end but in such a way, and by such conditions. Whence it seems a clear consequence, that the supreme unlimited agent uses no tool or instrument at all. The will of an Omnipotent Spirit is no sooner exerted than executed, without the application of means; which, if they are employed by inferior agents, it is not upon account of any real efficacy that is in them, or necessary aptitude to produce any effect, but merely in compliance with the laws of nature, or those conditions prescribed to them by the First Cause, who is Himself above all limitation or prescription whatsoever. [Dialogues, 2]

Common Sense

I am content . . . to appeal to the common sense of the world for the truth of my notion. Ask the gardener why he thinks yonder cherry-tree exists in the garden, and he shall tell you, because he sees and feels it; in a word, because he perceives it by his senses. Ask him why he thinks an orange-tree not to be there, and he shall tell you, because he does not perceive it. What he perceives by sense, that he terms a real, being, and says it is or exists; but, that which is not perceivable, the same, he says, has no being. . . . The question between the materialists and me is not, whether things have a real existence out of the mind of this or that person, but whether they have an absolute existence, distinct from being perceived by God, and exterior to all minds. [Dialogues, 3]

God and Evil

Hyl. You are not aware, Philonous, that in making God the immediate Author of all the motions in nature, you make Him the Author of murder, sacrilege, adultery, and the like heinous sins.

Phil. In answer to that, I observe, first, that the imputation of guilt is the same, whether a person commits an action with or without an instrument. In case therefore you suppose God to act by the mediation of an instrument or occasion, called matter, you as truly make Him the author of sin as I, who think Him the immediate agent in all those operations vulgarly ascribed to Nature. I farther observe that sin or moral turpitude doth not consist in the outward physical action or motion, but in the internal deviation of the will from the laws of reason and religion. This is plain, in that the killing an enemy in a battle, or putting a criminal legally to death, is not thought sinful; though the outward act be the very same with that in the case of murder. Since, therefore, sin doth not consist in the physical action, the making God an immediate cause of all such actions is not making Him the Author of sin. Lastly, I have nowhere said that God is the only agent who produces all the motions in bodies. It is true I have denied there are any other agents besides spirits; but this is very consistent with allowing to thinking rational beings, in the production of motions, the use of limited powers, ultimately indeed derived from God, but immediately under the direction of their own wills, which is sufficient to entitle them to all the guilt of their actions. [Dialogues, 3]

DAVID HUME (1711–1776)

Scottish empiricist philosopher and skeptic who argued that causal connections are grounded in mental habits.

All Ideas Copied from Impressions

Here therefore we may divide all the perceptions of the mind into two classes or species, which are distinguished by their different degrees of force and vivacity. The less forcible and lively are commonly denominated thoughts or ideas. The other species want a name in our language, and in most others; I suppose, because it was not requisite for any, but philosophical purposes, to rank them under a general term or appellation. Let us, therefore, use a little freedom, and call them impressions; employing that word in a sense somewhat different from the usual. By the term impression, then, I mean all our more lively perceptions, when we hear, or see, or feel, or love, or hate, or desire, or will. And impressions are distinguished from ideas, which are the less lively perceptions, of which we are conscious, when we reflect on any of those sensations or movements above mentioned. . . . .

But though our thought seems to possess this unbounded liberty, we shall find, upon a nearer examination, that it is really confined within very narrow limits, and that all this creative power of the mind amounts to no more than the faculty of compounding, transposing, augmenting, or diminishing the materials afforded us by the senses and experience. When we think of a golden mountain, we only join two consistent ideas, gold, and mountain, with which we were formerly acquainted. A virtuous horse we can conceive; because, from our own feeling, we can conceive virtue; and this we may unite to the figure and shape of a horse, which is an animal familiar to us. In short, all the materials of thinking are derived either from our outward or inward sentiment: The mixture and composition of these belongs alone to the mind and will. Or, to express myself in philosophical language, all our ideas or more feeble perceptions are copies of our impressions or more lively ones. . . .

When we entertain, therefore, any suspicion that a philosophical term is employed without any meaning or idea (as is but too frequent), we need but enquire, from what impression is that supposed idea derived? And if it be impossible to assign any, this will serve to confirm our suspicion. By bringing ideas into so clear a light we may reasonably hope to remove all dispute, which may arise, concerning their nature and reality. [Enquiry Concerning Human Understanding, 2]

Association of Ideas

To me, there appear to be only three principles of connection among ideas, namely, Resemblance, Contiguity in time or place, and Cause or Effect.

That these principles serve to connect ideas will not, I believe, be much doubted. A picture naturally leads our thoughts to the original [i.e., resemblance]: the mention of one apartment in a building naturally introduces an enquiry or discourse concerning the others [i.e., contiguity]: and if we think of a wound, we can scarcely forbear reflecting on the pain which follows it [i.e., causality]. But that this enumeration is complete, and that there are no other principles of association except these, may be difficult to prove to the satisfaction of the reader, or even to a man’s own satisfaction. All we can do, in such cases, is to run over several instances, and examine carefully the principle which binds the different thoughts to each other, never stopping till we render the principle as general as possible. The more instances we examine, and the more care we employ, the more assurance shall we acquire, that the enumeration, which we form from the whole, is complete and entire. [Enquiry Concerning Human Understanding, 3]


To be fully acquainted, therefore, with the idea of power or necessary connection, let us examine its impression; and in order to find the impression with greater certainty, let us search for it in all the sources, from which it may possibly be derived.

When we look about us towards external objects, and consider the operation of causes, we are never able, in a single instance, to discover any power or necessary connection; any quality, which binds the effect to the cause, and renders the one an infallible consequence of the other. We only find, that the one does actually, in fact, follow the other. The impulse of one billiard- ball is attended with motion in the second. This is the whole that appears to the outward senses. The mind feels no sentiment or inward impression from this succession of objects: Consequently, there is not, in any single, particular instance of cause and effect, any thing which can suggest the idea of power or necessary connection. . . .

It appears, then, that this idea of a necessary connection among events arises from a number of similar instances which occur of the constant conjunction of these events; nor can that idea ever be suggested by any one of these instances, surveyed in all possible lights and positions. But there is nothing in a number of instances, different from every single instance, which is supposed to be exactly similar; except only, that after a repetition of similar instances, the mind is carried by habit, upon the appearance of one event, to expect its usual attendant, and to believe that it will exist. This connection, therefore, which we feel in the mind, this customary transition of the imagination from one object to its usual attendant, is the sentiment or impression from which we form the idea of power or necessary connection. Nothing farther is in the case. Contemplate the subject on all sides; you will never find any other origin of that idea. This is the sole difference between one instance, from which we can never receive the idea of connection, and a number of similar instances, by which it is suggested. The first time a man saw the communication of motion by impulse, as by the shock of two billiard-balls, he could not pronounce that the one event was connected: But only that it was conjoined with the other. After he has observed several instances of this nature, he then pronounces them to be connected. What alteration has happened to give rise to this new idea of connection? Nothing but that he now feels these events to be connected in his imagination, and can readily foretell the existence of one from the appearance of the other. When we say, therefore, that one object is connected with another, we mean only that they have acquired a connection in our thought, and give rise to this inference, by which they become proofs of each other’s existence: A conclusion which is somewhat extraordinary, but which seems founded on sufficient evidence. [Enquiry Concerning Human Understanding, 7]

Personal Identity

There are some philosophers who imagine we are every moment intimately conscious of what we call our self; that we feel its existence and its continuance in existence; and are certain, beyond the evidence of a demonstration, both of its perfect identity and simplicity. The strongest sensation, the most violent passion, say they, instead of distracting us from this view, only fix it the more intensely, and make us consider their influence on self either by their pain or pleasure. To attempt a further proof of this were to weaken its evidence; since no proof can be derived from any fact of which we are so intimately conscious; nor is there any thing of which we can be certain if we doubt of this.

Unluckily all these positive assertions are contrary to that very experience which is pleaded for them; nor have we any idea of self, after the manner it is here explained. For, from what impression could this idea be derived? . . . For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe any thing but the perception. . . .

The mind is a kind of theatre, where several perceptions successively make their appearance; pass, repass, glide away, and mingle in an infinite variety of postures and situations. There is properly no simplicity in it at one time, nor identity in different, whatever natural propension we may have to imagine that simplicity and identity. The comparison of the theatre must not mislead us. They are the successive perceptions only, that constitute the mind; nor have we the most distant notion of the place where these scenes are represented, or of the materials of which it is composed. [A Treatise of Human Nature, 1.4.6]


A wise man, therefore, proportions his belief to the evidence. In such conclusions as are founded on an infallible experience, he expects the event with the last degree of assurance, and regards his past experience as a full proof of the future existence of that event. In other cases, he proceeds with more caution: He weighs the opposite experiments: He considers which side is supported by the greater number of experiments: To that side he inclines, with doubt and hesitation; and when at last he fixes his judgement, the evidence exceeds not what we properly call probability. All probability, then, supposes an opposition of experiments and observations, where the one side is found to overbalance the other, and to produce a degree of evidence, proportioned to the superiority. A hundred instances or experiments on one side, and fifty on another, afford a doubtful expectation of any event; though a hundred uniform experiments, with only one that is contradictory, reasonably beget a pretty strong degree of assurance. In all cases, we must balance the opposite experiments, where they are opposite, and deduct the smaller number from the greater, in order to know the exact force of the superior evidence. . . .

A miracle is a violation of the laws of nature; and as a firm and unalterable experience has established these laws, the proof against a miracle, from the very nature of the fact, is as entire as any argument from experience can possibly be imagined. Why is it more than probable, that all men must die; that lead cannot, of itself, remain suspended in the air; that fire consumes wood, and is extinguished by water; unless it be, that these events are found agreeable to the laws of nature, and there is required a violation of these laws, or in other words, a miracle to prevent them? Nothing is esteemed a miracle, if it ever happen in the common course of nature. It is no miracle that a man, seemingly in good health, should die on a sudden: Because such a kind of death, though more unusual than any other, has yet been frequently observed to happen. But it is a miracle, that a dead man should come to life; because that has never been observed in any age or country. There must, therefore, be a uniform experience against every miraculous event, otherwise the event would not merit that appellation. And as a uniform experience amounts to a proof, there is here a direct and full proof, from the nature of the fact, against the existence of any miracle; nor can such a proof be destroyed, or the miracle rendered credible, but by an opposite proof, which is superior. . . .

Upon the whole, then, it appears, that no testimony for any kind of miracle has ever amounted to a probability, much less to a proof; and that, even supposing it amounted to a proof, it would be opposed by another proof; derived from the very nature of the fact, which it would endeavor to establish. It is experience only, which gives authority to human testimony; and it is the same experience, which assures us of the laws of nature. When, therefore, these two kinds of experience are contrary, we have nothing to do but subtract the one from the other, and embrace an opinion, either on one side or the other, with that assurance which arises from the remainder. But according to the principle here explained, this subtraction, with regard to all popular religions, amounts to an entire annihilation; and therefore we may establish it as a maxim, that no human testimony can have such force as to prove a miracle, and make it a just foundation for any such system of religion. . . .

So that, upon the whole, we may conclude, that the Christian Religion not only was at first attended with miracles, but even at this day cannot be believed by any reasonable person without one. Mere reason is insufficient to convince us of its veracity: And whoever is moved by Faith to assent to it, is conscious of a continued miracle in his own person, which subverts all the principles of his understanding, and gives him a determination to believe what is most contrary to custom and experience. [Enquiry Concerning Human Understanding, 10]

Morality and Sentiment

Take any action allowed to be vicious; willful murder, for instance. Examine it in all lights, and see if you can find that matter of fact, or real existence, which you call vice. In whichever way you take it, you find only certain passions, motives, volitions, and thoughts. There is no other matter of fact in the case. The vice entirely escapes you, as long as you consider the object. You never can find it, till you turn your reflection into your own breast, and find a sentiment of disapprobation, which arises in you, towards this action. Here is a matter of fact; but it is the object of feeling, not of reason. It lies in yourself, not in the object. So that when you pronounce any action or character to be vicious, you mean nothing, but that from the constitution of your nature you have a feeling or sentiment of blame from the contemplation of it. Vice and virtue, therefore, may be compared to sounds, colors, heat, and cold, which, according to modern philosophy, are not qualities in objects, but perceptions in the mind: and this discovery in morals, like that other in physics, is to be regarded as a considerable advancement of the speculative sciences; though, like that too, it has little or no influence on practice. Nothing can be more real, or concern us more, than our own sentiments of pleasure and uneasiness; and if these be favorable to virtue, and unfavorable to vice, no more can be requisite to the regulation of our conduct and behavior.

I cannot forbear adding to these reasonings an observation, which may, perhaps, be found of some importance. In every system of morality which I have hitherto met with, I have always remarked, that the author proceeds for some time in the ordinary way of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when of a sudden I am surprised to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is, however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, it is necessary that it should be observed and explained; and at the same time that a reason should be given, for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it. But as authors do not commonly use this precaution, I shall presume to recommend it to the readers; and am persuaded, that this small attention would subvert all the vulgar systems of morality, and let us see that the distinction of vice and virtue is not founded merely on the relations of objects, nor is perceived by reason.

Thus the course of the argument leads us to conclude, that since vice and virtue are not discoverable merely by reason, or the comparison of ideas, it must be by means of some impression or sentiment they occasion, that we are able to mark the difference between them. Our decisions concerning moral rectitude and depravity are evidently perceptions; and as all perceptions are either impressions or ideas, the exclusion of the one is a convincing argument for the other. Morality therefore, is more properly felt than judged of; though this feeling or sentiment is commonly so soft and gentle that we are apt to confound it with an idea, according to our common custom of taking all things for the same which have any near resemblance to each other. [A Treatise of Human Nature, 3.1.1-2]


The intense view of these manifold contradictions and imperfections in human reason has so wrought upon me, and heated my brain, that I am ready to reject all belief and reasoning, and can look upon no opinion even as more probable or likely than another. Where am I, or what? From what causes do I derive my existence, and to what condition shall I return? Whose favor shall I court, and whose anger must I dread? What beings surround me? and on whom have I any influence, or who have any influence on me? I am confounded with all these questions, and begin to fancy myself in the most deplorable condition imaginable, environed with the deepest darkness, and utterly deprived of the use of every member and faculty.

Most fortunately it happens, that since reason is incapable of dispelling these clouds, Nature herself suffices to that purpose, and cures me of this philosophical melancholy and delirium, either by relaxing this bent of mind, or by some avocation, and lively impression of my senses, which obliterate all these chimeras. I dine, I play a game of backgammon, I converse, and am merry with my friends; and when, after three or four hours’ amusement, I would return to these speculations, they appear so cold, and strained, and ridiculous, that I cannot find in my heart to enter into them any further. . . .

At the time, therefore, that I am tired with amusement and company, and have indulged a reverie in my chamber, or in a solitary walk by a river side, I feel my mind all collected within itself, and am naturally inclined to carry my view into all those subjects, about which I have met with so many disputes in the course of my reading and conversation. . . . And in this respect I make bold to recommend philosophy, and shall not scruple to give it the preference to superstition of every kind or denomination. For as superstition arises naturally and easily from the popular opinions of mankind, it seizes more strongly on the mind, and is often able to disturb us in the conduct of our lives and actions. Philosophy, on the contrary, if just, can present us only with mild and moderate sentiments; and if false and extravagant, its opinions are merely the objects of a cold and general speculation, and seldom go so far as to interrupt the course of our natural propensities. [A Treatise of Human Nature,  1.4.7]



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