Ancient and Medieval Philosophy: The Origin of Western Thought – Aristotle

By Dr. Garth Kemerling / 11.12.2011
Professor of Philosophy
Capella University

Philosophy Pages

Logical Methods

The greatest and most influential of Plato’s students was Aristotle, who established his own school at Athens. Although his writing career probably began with the production of quasi-Platonic dialogues, none of them have survived. Instead, our knowledge of Aristotle’s doctrines must be derived from highly-condensed, elliptical works that may have been lecture notes from his teaching at the Lyceum. Although not intended for publication, these texts reveal a brilliant mind at work on many diverse topics.

Philosophically, the works of Aristotle reflect his gradual departure from the teachings of Plato and his adoption of a new approach. Unlike Plato, who delighted in abstract thought about a supra-sensible realm of forms, Aristotle was intensely concrete and practical, relying heavily upon sensory observation as a starting-point for philosophical reflection. Interested in every area of human knowledge about the world, Aristotle aimed to unify all of them in a coherent system of thought by developing a common methodology that would serve equally well as the procedure for learning about any discipline.

For Aristotle, then, logic is the instrument (the “organon”) by means of which we come to know anything. He proposed as formal rules for correct reasoning the basic principles of the categorical logic that was universally accepted by Western philosophers until the nineteenth century. This system of thought regards assertions of the subject-predicate form as the primary expressions of truth, in which features or properties are shown to inhere in individual substances. In every discipline of human knowledge,then, we seek to establish the things of some sort have features of a certain kind.

Aristotle further supposed that this logical scheme accurately represents the true nature of reality. Thought, language, and reality are all isomorphic, so careful consideration of what we say can help us to understand the way things really are. Beginning with simple descriptions of particular things, we can eventually assemble our information in order to achieve a comprehensive view of the world.

Applying the Categories

The initial book in Aristotle’s collected logical works is the Categories, an analysis of predication generally. It begins with a distinction among three ways in which the meaning of different uses of a predicate may be related to each other: homonymy, synonymy, and paronymy (in some translations, “equivocal,” “univocal,” and “derivative”). Homonymous uses of a predicate have entirely different explanations, as in “With all that money, she’s really loaded,” and “After all she had to drink, she’s really loaded.” Synonymous uses have exactly the same account, as in “Cows are mammals,” and “Dolphins are mammals.” Paronymous attributions have distinct but related senses, as in “He is healthy,” and “His complexion is healthy.” (Categories 1) It is important in every case to understand how this use of a predicate compares with its other uses.

So long as we are clear about the sort of use we are making in each instance, Aristotle proposed that we develop descriptions of individual things that attribute to each predicates (or categories) of ten different sorts. Substance is the most crucial among these ten, since it describes the thing in terms of what it most truly is. For Aristotle, primary substance is just the individual thing itself, which cannot be predicated of anything else. But secondary substances are predicable, since they include the species and genera to which the individual thing belongs. Thus, the attribution of substance in this secondary sense establishes the essence of each particular thing.

The other nine categories—quantity, quality, relative, where, when, being in a position, having, acting on, and being affected by—describe the features which distinguish this individual substance from others of the same kind; they admit of degrees and their contraries may belong to the same thing. (Categories4) Used in combination, the ten kinds of predicate can provide a comprehensive account of what any individual thing is. Thus, for example: Chloë is a dog who weighs forty pounds, is reddish-brown, and was one of a litter of seven. She is in my apartment at 7:44 a.m. on June 3, 1997, lying on the sofa, wearing her blue collar, barking at a squirrel, and being petted. Aristotle supposed that anything that is true of any individual substance could, in principle, be said about it in one of these ten ways.

The Nature of Truth

Another of Aristotle’s logical works, On Interpretation, considers the use of predicates in combination with subjects to form propositions or assertions, each of which is either true or false. We usually determine the truth of a proposition by reference to our experience of the reality it conveys, but Aristotle recognized that special difficulties arise in certain circumstances.

Although we grant (and can often even discover) the truth or falsity of propositions about past and present events, propositions about the future seem problematic. If a proposition about tomorrow is true (or false) today, then the future event it describes will happen (or not happen) necessarily; but if such a proposition is neither true nor false, then there is no future at all. Aristotle’s solution was to maintain that the disjunction is necessarily true today even though neither of its disjuncts is. Thus, it is necessary that either tomorrow’s event will occur or it will not, but it is neither necessary that it will occur nor necessary that it will not occur. (On Interpretation 9)

Aristotle’s treatment of this specific problem, like his more general attempt to sort out the nature of the relationship between necessity and contingency inOn Interpretation 12-13, is complicated by the assumption that the structure of logic models the nature of reality. He must try to explain not just the way we speak, but the way the world therefore must be.

Demonstrative Science

Finally, in the Prior Analytics and Posterior Analytics, Aristotle offered a detailed account of the demonstrative reasoning required to substantiatetheoretical knowledge. Using mathematics as a model, Aristotle presumed that all such knowledge must be derived from what is already known. Thus, the process of reasoning by syllogism employs a formal definition of validity that permits the deduction of new truths from established principles. The goal is to provide an account of why things happen the way they do, based solely upon what we already know.

In order to achieve genuine necessity, this demonstrative science must be focussed on the essences rather than the accidents of things, on what is “true of any case as such,” rather than on what happens to be “true of each case in fact.” It’s not enough to know that it rained today; we must be able to figure out the general meteorological conditions under which rain is inevitable. When we reason from necessary universal and affirmative propositions about the essential features of things while assuming as little as possible, the resulting body of knowledge will truly deserve the name of science.

The Four Causes

Applying the principles developed in his logical treatises, Aristotle offered a general account of the operation of individual substances in the natural world. He drew a significant distinction between things of two sorts: those that move only when moved by something else and those that are capable of moving themselves. In separate treatises, Aristotle not only proposed a proper description of things of each sort but also attempted to explain why they function as they do.

Aristotle considered bodies and their externally-produced movement in thePhysics. Three crucial distinctions determine the shape of this discussion of physical science. First, he granted from the outset that, because of the difference in their origins, we may need to offer different accounts for the functions of natural things and those of artifacts. Second, he insisted that we clearly distinguish between the basic material and the form which jointly constitute the nature of any individual thing. Finally, Aristotle emphasized the difference between things as they are and things considered in light of theirends or purposes.

Armed with these distinctions, Aristotle proposed in Physics II, 3 that we employ four very different kinds of explanatory principle {Gk. αιτιον [aition]} to the question of why a thing is, the four causes:

The material cause is the basic stuff out of which the thing is made. The material cause of a house, for example, would include the wood, metal, glass, and other building materials used in its construction. All of these things belong in an explanation of the house because it could not exist unless they were present in its composition.

The formal cause {Gk. ειδος [eidos]} is the pattern or essence in conformity with which these materials are assembled. Thus, the formal cause of our exemplary house would be the sort of thing that is represented on a blueprint of its design. This, too, is part of the explanation of the house, since its materials would be only a pile of rubble (or a different house) if they were not put together in this way.

The efficient cause is the agent or force immediately responsible for bringing this matter and that form together in the production of the thing. Thus, the efficient cause of the house would include the carpenters, masons, plumbers, and other workers who used these materials to build the house in accordance with the blueprint for its construction. Clearly the house would not be what it is without their contribution.

Lastly, the final cause {Gk. τελος [télos]} is the end or purpose for which a thing exists, so the final cause of our house would be to provide shelter for human beings. This is part of the explanation of the house’s existence because it would never have been built unless someone needed it as a place to live.

Causes of all four sorts are necessary elements in any adequate account of the existence and nature of the thing, Aristotle believed, since the absence or modification of any one of them would result it the existence of a thing of some different sort. Moreover, an explanation that includes all four causes completely captures the significance and reality of the thing itself.

The Appearance of Chance

Notice that the four causes apply more appropriately to artifacts than to natural objects. The rise of modern science resulted directly from a rejection of the Aristotelean notion of final causes in particular. Still, the scheme works so well for artifacts that we often find ourselves attributing some purpose even to the apparently pointless events of the natural world.

In many applications the formal, efficient, and final causes tend to be combined in a single being that designs and builds the thing for some specific purpose. Thus, the fundamental differentiation in the Aristotelean world turns out to be between inert matter on the one hand and intelligent agency on the other. As we shall soon see, this provides a natural explanation for the functions of animate natural organisms.

As for things that appear to arise by pure chance, Aristotle argued that since the purposeful origination described by the four causes is the normal order of the world, these instances must either be things that should have had some cause but happen to lack it or (more likely) things that actually do have causes of which we are simply unaware. The craft evident in the manufacture of artifacts, he believed, is evidence for the purposive character of nature, and it shares the same necessity, even though we are sometimes ignorant of its internal operations. (Physics II, 8)

Although I would be hard-pressed to come up with a final cause for the existence of the mosquito that is now biting me, for example, Aristotle supposed that there must ultimately be some explanation for its present existence and activity. Many generations of Western philosophers, especially those concerned with reconciling Christian doctrine with philosophy, would explicitly defend a similar view.

Forms and Souls


Aristotle considered the most fundamental features of reality in the twelve books of the Μεταφυσικη (Metaphysics). Although experience of what happens is a key to all demonstrative knowledge, Aristotle supposed that the abstract study of “being qua being” must delve more deeply, in order to understand why things happen the way they do. A quick review of past attempts at achieving this goal reveals that earlier philosophers had created more difficult questions than they had answered: the Milesians over-emphasized material causes;Anaxagoras over-emphasized mind; and Plato got bogged down in the theory of forms. Aristotle intended to do better.

Although any disciplined study is promising because there is an ultimate truth to be discovered, the abstractness of metaphysical reasoning requires that we think about the processes we are employing even as we use them in search of that truth. As always, Aristotle assumed that the structure of language and logic naturally mirrors the way things really are. Thus, the major points of each book are made by carefully analyzing our linguistic practices as a guide to the ultimate nature of what is.

Fundamental Truths

It is reasonable to begin, therefore, with the simplest rules of logic, which embody the most fundamental principles applying to absolutely everything that is:

The Law of Non-Contradiction in logic merely notes that no assertion is both true and false, but applied to reality this simple rule entails that nothing can both “be . . . ” and “not be . . . ” at the same time, although we will of course want to find room to allow for things to change. Thus, neither strict Protagorean relativism nor Parmenidean immutability offer a correct account of the nature of reality. (Metaphysics IV 3-6)

The Law of Excluded Middle in logic states the necessity that either an assertion or its negation must be true, and this entails that there is no profound indeterminacy in the realm of reality. Although our knowledge of an assertion may sometimes fall short of what we need in order to decide whether it is true or false, we can be sure that either it or its negation is true. (Metaphysics IV 7-8)

In order to achieve its required abstract necessity, all of metaphysics must be constructed from similar principles. Aristotle believed this to be the case because metaphysics is concerned with a genuinely unique subject matter. While natural science deals with moveable, separable things and mathematics focusses upon immoveable, inseparable things, metaphysics (especially in its highest, most abstract varieties) has as its objects only things that are both immoveable and separable. Thus, what we learn in metaphysics is nothing less than the immutable eternal nature, or essence, of individual things.


In the central books of the Metaphysics, Aristotle tried to develop an adequate analysis of subject-predicate judgments. Since logic and language rely heavily upon the copulative use of “is,” careful study of these uses should reveal the genuine relationship that holds between substances and their features. Of course, Plato had already offered an extended account of this relationship, emphasizing the reality of the abstract forms rather than their material substratum.

But Aristotle argued that the theory of forms is seriously flawed: it is not supported by good arguments; it requires a form for each thing; and it is too mathematical. Worst of all, on Aristotle’s view, the theory of forms cannot adequately explain the occurrence of change. By identifying the thing with its essence, the theory cannot account for the generation of new substances. (Metaphysics VII) A more reasonable position must differentiate between matter and form and allow for a dynamic relation between the two.

Aristotle therefore maintained that each individual substance is ahylomorphic composite involving both matter and form together. Ordinary predication, then, involves paronymously attributing an abstract universal of a concrete individual, and our experience of this green thing is more significant than our apprehension of the form of greenness. This account, with its emphasis on the particularity of individual substances, provided Aristotle with a firm foundation in practical experience.

Higher Truths

Aristotle also offered a detailed account of the dynamic process of change. A potentiality {Gk. δυναμις [dynamis]} is either the passive capacity of a substance to be changed or (in the case of animate beings) its active capacity to produce change in other substances in determinate ways. An actuality {Gk. ενεργεια [energeia]} is just the realization of one of these potentialities, which is most significant when it includes not merely the movement but also its purpose. Becoming, then, is the process in which the potentiality present in one individual substance is actualized through the agency of something else which is already actual. (Metaphysics IX) Thus, for Aristotle, change of any kind requires the actual existence of something which causes the change.

The higher truths of what Aristotle called “theology” arise from an application of these notions to the more purely speculative study of being quabeing. Since every being is a composite whose form and matter have been brought together by some cause, and since there cannot be infinitely many such causes, he concluded that everything that happens is ultimately attributable to a single universal cause, itself eternal and immutable. (Metaphysics XII 6) This self-caused “first mover,” from which all else derives, must be regarded as a mind, whose actual thinking is its whole nature. The goodness of the entire universe, Aristotle supposed, resides in its teleological unity as the will of a single intelligent being.

The Nature of Souls

According to Aristotle, every animate being is a living thing which can move itself only because it has a soul. Animals and plants, along with human beings, are more like each other than any of them are like any inanimate object, since each of them has a soul. Thus, his great treatise on psychology, On The Soul, offers interconnected explanations for the functions and operations of all living organisms.

All such beings, on Aristotle’s view, have a nutritive soul which initiates and guides their most basic functions, the absorption of food, growth, and reproduction of its kind. All animals (and perhaps some plants) also have a sensitive soul by means of which they perceive features of their surroundings and move in response to the stimuli this provides. Human beings also possess (in addition to the rest) a rational soul that permits representation and thought. (On the Soul II 2)

Notice that each living thing has just one soul, the actions of which exhibit some degree of nutritive, sensitive, and/or rational functioning. This soul is the formal, efficient, and final cause of the existence of the organism; only its material cause resides purely in the body. Thus, all of the operations of the organism are to be explained in terms of the functions of its soul.

Human Knowledge

Sensation is the passive capacity for the soul to be changed through the contact of the associated body with external objects. In each variety of sensation, the normal operations of the appropriate organ of sense result in the soul’s becoming potentially what the object is in actuality. Thus, without any necessary exchange of matter, the soul takes on the form of the object: when I feel the point of a pin, its shape makes an impression on my finger, conveying this form to my sensitive soul (resulting in information). (On the Soul II 5)

Thought is the more active process of engaging in the manipulation of forms without any contact with external objects at all. Thus, thinking is potentially independent of the objects of thought, from which it abstracts the form alone. Even the imagination, according to Aristotle, involves the operation of the common sense without stimulation by the sensory organs of the body. Hence, although all knowledge must begin with information acquired through the senses, its results are achieved by rational means. Transcending the sensory preoccupation with particulars, the soul employs the formal methods of logic to cognize the relationships among abstract forms. (On the Soul III 4)

Desire is the origin of movement toward some goal. Every animate being, to some degree, is capable of responding to its own internal states and those of its external environment in such a way as to alleviate the felt absence or lack of some pleasure or the felt presence of some pain. Even actions taken as a result of intellectual deliberation, Aristotle supposed, produce motion only through the collateral evocation of a concrete desire. (On the Soul III 10)

Ethics and the Virtues

Chart from BC Resources . net; based on the Tredennick translation

The Goal of Ethics

Aristotle applied the same patient, careful, descriptive approach to his examination of moral philosophy in the Εθικη Νικομαχοι (Nicomachean Ethics). Here he discussed the conditions under which moral responsibility may be ascribed to individual agents, the nature of the virtues and vices involved in moral evaluation, and the methods of achieving happiness in human life. The central issue for Aristotle is the question of character or personality — what does it take for an individual human being to be a good person?

Every activity has a final cause, the good at which it aims, and Aristotle argued that since there cannot be an infinite regress of merely extrinsic goods, there must be a highest good at which all human activity ultimately aims. (Nic. Ethics I 2) This end of human life could be called happiness (or living well), of course, but what is it really? Neither the ordinary notions of pleasure, wealth, and honor nor the philosophical theory of forms provide an adequate account of this ultimate goal, since even individuals who acquire the material goods or achieve intellectual knowledge may not be happy.

According to Aristotle, things of any variety have a characteristic function that they are properly used to perform. The good for human beings, then, must essentially involve the entire proper function of human life as a whole, and this must be an activity of the soul that expresses genuine virtue or excellence. (Nic. Ethics I 7) Thus, human beings should aim at a life in full conformity with their rational natures; for this, the satisfaction of desires and the acquisition of material goods are less important than the achievement of virtue. A happy person will exhibit a personality appropriately balanced between reasons and desires, with moderation characterizing all. In this sense, at least, “virtue is its own reward.” True happiness can therefore be attained only through the cultivation of the virtues that make a human life complete.

The Nature of Virtue

Ethics is not merely a theoretical study for Aristotle. Unlike any intellectual capacity, virtues of character are dispositions to act in certain ways in response to similar situations, the habits of behaving in a certain way. Thus, good conduct arises from habits that in turn can only be acquired by repeated action and correction, making ethics an intensely practical discipline.

Each of the virtues is a state of being that naturally seeks its mean {Gk. μεσος [mesos]} relative to us. According to Aristotle, the virtuous habit of action is always an intermediate state between the opposed vices of excess and deficiency: too much and too little are always wrong; the right kind of action always lies in the mean. (Nic. Ethics II 6) Thus, for example:

with respect to acting in the face of danger,
courage {Gk. ανδρεια [andreia]} is a mean between
the excess of rashness and the deficiency of cowardice;

with respect to the enjoyment of pleasures,
temperance {Gk. σωφρσυνη [sophrosúnê]} is a mean between
the excess of intemperance and the deficiency of insensibility;

with respect to spending money,
generosity is a mean between
the excess of wastefulness and the deficiency of stinginess;

with respect to relations with strangers,
being friendly is a mean between
the excess of being ingratiating and the deficiency of being surly; and

with respect to self-esteem,
magnanimity {Gk. μεγαλοψυχι&alpha [megalopsychia]} is a mean between
the excess of vanity and the deficiency of pusillanimity.

Notice that the application of this theory of virtue requires a great deal of flexibility: friendliness is closer to its excess than to its deficiency, while few human beings are naturally inclined to undervalue pleasure, so it is not unusual to overlook or ignore one of the extremes in each of these instances and simply to regard the virtue as the opposite of the other vice.Although the analysis may be complicated or awkward in some instances, the general plan of Aristotle’s ethical doctrine is clear: avoid extremes of all sorts and seek moderation in all things. Not bad advice, surely. Some version of this general approach dominated Western culture for many centuries.

Voluntary Action

Because ethics is a practical rather than a theoretical science, Aristotle also gave careful consideration to the aspects of human nature involved in acting and accepting moral responsibility. Moral evaluation of an action presupposesthe attribution of responsibility to a human agent. But in certain circumstances, this attribution would not be appropriate. Responsible action must be undertaken voluntarily, on Aristotle’s view, and human actions are involuntary under two distinct conditions: (Nic. Ethics III 1)

First, actions that are produced by some external force (or, perhaps, under an extreme duress from outside the agent) are taken involuntarily, and the agent is not responsible for them. Thus, if someone grabs my arm and uses it to strike a third person, I cannot reasonably be blamed (or praised) morally for what my arm has done.

Second, actions performed out of ignorance are also involuntary. Thus, if I swing my arm for exercise and strike the third party who (unbeknownst to me) is standing nearby, then again I cannot be held responsible for having struck that person. Notice that the sort of ignorance Aristotle is willing to regard as exculpatory is always of lack of awareness of relevant particulars. Striking other people while claiming to be ignorant of the moral rule under which it is wrong to do so would not provide any excuse on his view.

As we’ll soon see, decisions to act voluntarily rely upon deliberation about the choice among alternative actions that the individual could perform. During the deliberative process, individual actions are evaluated in light of the good, and the best among them is then chosen for implementation. Under these conditions, Aristotle supposed, moral actions are within our power to perform or avoid; hence, we can reasonably be held responsible for them and their consequences. Just as with health of the body, virtue of the soul is a habit that can be acquired (at least in part) as the result of our own choices.

Deliberate Choice

Although the virtues are habits of acting or dispositions to act in certain ways, Aristotle maintained that these habits are acquired by engaging in proper conduct on specific occasions and that doing so requires thinking about what one does in a specific way. Neither demonstrative knowledge of the sort employed in science nor aesthetic judgment of the sort applied in crafts are relevant to morality. The understanding {Gk. διανοια [diánoia]} can only explore the nature of origins of things, on Aristotle’s view, and wisdom {Gk. σοφια [sophía]} can only trace the demonstratable connections among them.

But there is a distinctive mode of thinking that does provide adequately for morality, according to Aristotle: practical intelligence or prudence {Gk. φρνησις [phrónêsis]}. This faculty alone comprehends the true character of individual and community welfare and applies its results to the guidance of human action. Acting rightly, then, involves coordinating our desires with correct thoughts about the correct goals or ends.

This is the function of deliberative reasoning: to consider each of the many actions that are within one’s power to perform, considering the extent to which each of them would contribute to the achievement of the appropriate goal or end, making a deliberate choice to act in the way that best fits that end, and then voluntarily engaging in the action itself. (Nic. Ethics III 3) Although virtue is different from intelligence, then, the acquisition of virtue relies heavily upon the exercise of that intelligence.

Weakness of the Will

But doing the right thing is not always so simple, even though few people deliberately choose to develop vicious habits. Aristotle sharply disagreed with Socrates’s belief that knowing what is right always results in doing it. The great enemy of moral conduct, on Aristotle’s view, is precisely the failure to behave well even on those occasions when one’s deliberation has resulted in clear knowledge of what is right.

Incontinent agents suffer from a sort of weakness of the will {Gk. ακρασια [akrásia]} that prevents them from carrying out actions in conformity with what they have reasoned. (Nic. Ethics VII 1) This may appear to be a simple failure of intelligence, Aristotle acknowledged, since the akratic individual seems not to draw the appropriate connection between the general moral rule and the particular case to which it applies. Somehow, the overwhelming prospect of some great pleasure seems to obscure one’s perception of what is truly good. But this difficulty, Aristotle held, need not be fatal to the achievement of virtue.

Although incontinence is not heroically moral, neither is it truly vicious. Consider the difference between an incontinent person, who knows what is right and aims for it but is sometimes overcome by pleasure, and an intemperate person, who purposefully seeks excessive pleasure. Aristotle argued that the vice of intemperance is incurable because it destroys the principle of the related virtue, while incontinence is curable because respect for virtue remains. (Nic. Ethics VII 8) A clumsy archer may get better with practice, while a skilled archer who chooses not to aim for the target will not.


In a particularly influential section of the Ethics, Aristotle considered the role of human relationships in general and friendship {Gk. φιλια [philia]} in particular as a vital element in the good life.

For without friends no one would choose to live, though he had all other goods.

Differentiating between the aims or goals of each, he distinguished three kinds of friendships that we commonly form. (Nic. Ethics VIII 3)A friendship for pleasure comes into being when two people discover that they have common interest in an activity which they can pursue together. Their reciprocal participation in that activity results in greater pleasure for each than either could achieve by acting alone. Thus, for example, two people who enjoy playing tennis might derive pleasure from playing each other. Such a relationship lasts only so long as the pleasure continues.

A friendship grounded on utility, on the other hand, comes into being when two people can benefit in some way by engaging in coordinated activity. In this case, the focus is on what use the two can derive from each other, rather than on any enjoyment they might have. Thus, for example, one person might teach another to play tennis for a fee: the one benefits by learning and the other benefits financially; their relationship is based solely on the mutual utility. A relationship of this sort lasts only so long as its utility.

A friendship for the good, however, comes into being when two people engage in common activities solely for the sake of developing the overall goodness of the other. Here, neither pleasure nor utility are relevant, but the good is. (Nic. Ethics VIII 4) Thus, for example, two people with heart disease might play tennis with each other for the sake of the exercise that contributes to the overall health of both. Since the good is never wholly realized, a friendship of this sort should, in principle, last forever.

Rather conservatively representing his own culture, Aristotle expressed some rather peculiar notions about the likelihood of forming friendships of these distinct varieties among people of different ages and genders. But the general description has some value nevertheless, especially in its focus on reciprocity. Mixed friendships—those in which one party is seeking one payoff while the other seeks a different one—are inherently unstable and prone to dissatisfaction.

Achieving Happiness

Aristotle rounded off his discussion of ethical living with a more detailed description of the achievement of true happiness. Pleasure is not a good in itself, he argued, since it is by its nature incomplete. But worthwhile activities are often associated with their own distinctive pleasures. Hence, we are rightly guided in life by our natural preference for engaging in pleasant activities rather than in unpleasant ones.

Genuine happiness lies in action that leads to virtue, since this alone provides true value and not just amusement. Thus, Aristotle held that contemplation is the highest form of moral activity because it is continuous, pleasant, self-sufficient, and complete. (Nic. Ethics X 8) In intellectual activity, human beings most nearly approach divine blessedness, while realizing all of the genuine human virtues as well.

Politics and Art

The Nature of Justice

Since friendship is an important feature of the good life and virtuous habits can be acquired through moral education and legislation, Aristotle regarded life within a moral community as a vital component of human morality. Even in the Ethics, he had noted that social order is presumed by the general concept of justice. (Nic. Ethics V 2)

Properly considered, justice is concerned with the equitability or fairness in interpersonal relations. Thus, Aristotle offered an account of distributive justice that made allowances for the social rectification of individual wrongs. Moreover, he noted that justice in the exchange of property requires careful definition in order to preserve equity. The broader concept of political justice, however, is to be recognized only within the context of an entire society. Thus, it deserves separate treatment in a different treatise.

Political Life

That treatise is Aristotle’s Politics, a comprehensive examination of the origins and structure of the state. Like Plato, Aristotle supposed that the need for a division of labor is the initial occasion of the formation of a society, whose structure will be modelled upon that of the family. (Politics I 2) But Aristotle (preferring the mean) declined to agree with Plato’s notion of commonly held property and argued that some property should be held privately.

Aristotle also drew a sharper distinction between morality and politics than Plato had done. Although a good citizen is a good person, on Aristotle’s view, the good person can be good even independently of the society. A good citizen, however, can exist only as a part of the social structure itself, so the state is in some sense prior to the citizen.

Depending upon the number of people involved in governing and the focus of their interests, Aristotle distinguished six kinds of social structure in three pairs:

A state with only one ruler is either a monarchy or a tyrrany;

A state with several rulers is either an aristocracy or an oligarchy; and

A state in which all rule is either a polity or a democracy.

In each pair, the first sort of state is one in which the rulers are concerned with the good of the state, while those of the second sort are those in which the rulers serve their own private interests. (Politics III 7)

Although he believed monarchy to be the best possible state in principle, Aristotle recognized that in practice it is liable to degenerate into the worst possible state, a tyrrany. He therefore recommended the formation of polity, or constitutional government, since its degenerate form is the least harmful of the bad kinds of government. As always, Aristotle defended the mean rather than run the risk of either extreme.


Another sharp contrast between Plato and Aristotle emerges in the latter’sPoetics, and analysis of the effects of dramatic art. Aristotle, unlike his teacher, supposed that the extravagant representation of powerful emotions is beneficial to the individual citizen, providing an opportunity for the cathartic release of unhealthy feelings rather than encouraging their development.

Tragedy in particular arouses our fear and pity, as we recognize the inherent flaw of the tragic hero. Having seen the outcome in dramatic form, we are less likely to commit similar acts of pride, Aristotle argued, so the literary arts have a direct benefit to human society. This provides no grounds for a Platonic notion of censorship of the arts.

Although their relative reputations often varied widely, the philosophies of Plato and Aristotle continued to exert a powerful influence throughout the following centuries. Even now, it is often suggested that Western thinkers are invariably either Platonic or Aristotelean. That is, each of us is inclined either toward the abstract, speculative, intellectual apprehension of reality, as Plato was, or toward the concrete, practical, sensory appreciation of reality, as Aristotle was. The differences between the two approaches may be too fundamental for argumentation or debate, but the coordination or synthesis of the two together is extremely difficult, so choice may be required.

Certainly the philosophy of the Middle Ages, to which we will devote the remainder of this semester, exhibits some form of this division. As Christian thinkers tried to find ways of accomodating their religious doctrines to the tradition of Greek philosophy, some version of Plato and some version of Aristotle were significant factors in their development.