Aristotle's Nicomachean Ethics is the first systematic treatise on ethics. Over two millennia after it was written, it is still among the best. Even philosophers and intellectuals not sympathetic to Aristotle's philosophy in general or his ethics in particular admit its greatness. It speaks to human beings about themselves and their relations to others as clearly, forcefully, and systematically today as it did when it was written (or dictated) 2,500 years ago. It would also be hard to over estimate its historical importance. Virtually every moral philosopher has to deal with the issues grappled with in the Nicomachean Ethics , and many of the positions argued for by Aristotle have been adopted, sometimes in an almost wholesale fashion, by other philosophers. St. Thomas Aquinas' ethics, for example, is very Aristotelian, both in its overall outline and its details. Without too much exaggeration, it would be called Christianized Aristotelianism. As the patron saint of the Catholic Church, Aquinas has thus passed on a large part of Aristotle's ethics to Christians the world over.

Aristotle was born in 384 BC at Stagira in Thrace. He was the son of Nicomachus, a physician to the king of Macedonia. At about the age of seventeen, Aristotle went to Athens to study and become a member of the Academy of Plato. Plato, the founder of the Academy, was himself the student of Socrates. Plato is usually, and rightly, thought to be the first systematic and comprehensive philosopher in Western civilization. (Socrates was not, and neither were the pre-Socratic philosophers: he developed no metaphysics, for example, and the pre-Socratics developed no ethics.) Every branch of philosophy was home to Plato. Aristotle studied at the Academy for over twenty years. He undoubtedly had extensive tutelage under and personal contact with Plato. Although he had great respect for Plato, he eventually came to disagree with him on a number of issues, some of them in ethics.

After Plato's death in 348 or 347 BC, Aristotle left Athens and eventually was invited to tutor Alexander, the son of Philip of Macedonia. This Alexander is more commonly known as Alexander the Great, and conquered many foreign lands. Eventually Alexander's empire included almost the entire ancient world. Despite tutoring Alexander for a number of years, Aristotle seems to have had little to no influence on him. (And vice versa: Alexander showed, by example, the importance of the idea of a political empire, but Aristotle's philosophy remained committed to the primacy of the much smaller city-state.)

Aristotle returned to Athens in 335 BC and founded his own school, the Lyceum. The fact that he did not return to the Academy was probably due in part to his drifting away from Plato's philosophy. Aristotle and his followers were known as Peripatetics, because of their habit of discoursing while walking. ('Peripatetic,' in Greek, means 'walker.') Alexander died in 323 BC, and because of a strong Greek antipathy to Alexander and Aristotle's prior association with him, Aristotle fled to Chalcis in Euboea . He died there in 322 BC.

Most scholars agree that there are at least two treatises by Aristotle on ethics: the Eudemian Ethics and the Nicomachean Ethics . The Eudemian Ethics is probably an earlier work, and is in general agreement with large portions of the Nicomachean Ethics , although there are some differences. Three books are even completely shared by the two treatises. The Eudemian Ethics might have been so-called because it was edited by Aristotle's student Eudemus, and the Nicomachean Ethics so-named because it was edited by Aristotle's son, Nichomachus. But no one really knows for sure.

As Bertrand Russell, a well-known British philosopher once observed, Aristotle is the first person to write like a professor. The Nicomachean Ethics is a treatise, and as such, it is systematic, well organized, and divided into appropriate subject-related sections. It is dry, dense, and dispassionate, but penetrating and insightful. The fruit of many years' thinking, it comprises ten books and many chapters. In all likelihood it, like Aristotle's other extant works, is pedagogical in nature, and is his lecture notes or transcripts of lecture notes compiled by his students.

For Aristotle, ethics is the art of living well-the art of human flourishing, as we would say today-but an individual cannot live well or flourish except in the context of the state. Ethics is thus for him a branch of politics, and his treatise the Politics completes and makes whole the philosophy of the Nicomachean Ethics . However, the Nicomachean Ethics can be read and understood on its own.

In many respects, Aristotle's approach to ethics is very different from that taken today. His ethics is not modeled on a legal system. There is no mention of fundamental human rights, for example, and no attempt is made to lay down hard and fast 'do' and 'don't' principles and rules, much less to organize such principles or rules into a hierarchy or coherent system. Aristotle's is an ethics not of principles and rules, but of character, character development, proper deportment, proper and appropriate relations to others, and proper feeling. His guiding idea is not 'breaking or keeping the law' but 'being or not being the best person possible.' It is, in a certain sense, an ethics of self-development, and duties to oneself figure prominently in it. (A legalistic ethics is concerned solely with behavior toward others.) Aristotle believes that if the good is properly understood, what is ethically good and what is good for a person do not diverge. Thus, the kind of tension that arises within principle-based ethics, between what is ethically good (not stealing the candy, say) and good for a person (stealing the candy) cannot arise. The demands of ethics and the demands of proper prudence or self-interest do not conflict.

This is ultimately rooted in Aristotle's conception of the good. Aristotle's ethics is through and through teleological, or purpose- or end-directed. "Every art and investigation, and every practical pursuit or undertaking, seems to aim at some good," he tells us at the very beginning of the Nicomachean Ethics , and the good might well be described as that at which all human actions aim. But what is this good which all human actions aim at?

HAPPINESS

Aristotle's answer is happiness, but "happiness" does not mean for him what it means today. Happiness is not a mere subjective state characterized by pleasantness or liking. It's not a bubbly, enjoyable feeling, or a feeling at all. Rather, it is faring well or flourishing, an objective state of affairs. Happiness, Aristotle says, is activity of the soul in accordance with virtue. 'Virtue' is an English/Latin translation of the Greek word 'arete,' which mean excellence. But the word 'virtue' does not have same "highly moralistic" connotations for Aristotle that it does for people today. The virtue or excellence of a thing is simply that feature (or features) of it which enables it to perform its proper function well. One virtue of a knife is its sharpness. One virtue of a car is its maneuverability. The question for Aristotle is, what is the virtue of man?

In order to answer that question, Aristotle thinks that we have to look into our own nature. It is by examining the nature of a knife or a car that we discover its excellences, and the same holds for human beings, Aristotle thinks. A human being is not a pig, for example, and so we should expect human excellence to differ from pig excellence. What we must do is discover the proper function of a human being by examining its nature, just as we do with a knife. This means we must look for something human beings can do and can do excellently better than any other beings. According to Aristotle, what this 'something' is is living rationally by employing our intelligence to make plans, to deliberate about which actions to perform, to our control emotions, to think about things, and to understand reality. Rationality is thus the definition of 'man,' and therefore the unique excellence of human beings. Living rationally, then, is living excellently or faring well, and happiness is rational activity of the soul, or, as Aristotle explicitly says, "the exercise of the soul's faculties in conformity with virtue in a complete life." (109815-20)

Two of the soul's faculties are identified by Aristotle as capable of engaging in rational and intellectual activity. One is the intellect, which reasons and understands. The other is the part of the soul which can listen to reason. Accordingly, there are two different kinds of activity and two different kinds of virtue. One kind of virtue is virtue in reasoning about universal and necessary things, such as God and heavenly bodies. Theology, astronomy, and physics are studies that belong to this category. This sort of virtue is intellectual virtue. The other kind of virtue, the virtue of 'listening to reason,' is moral virtue. Moral virtue concerns reasoning about and acting in accordance with what is fitting in respect to action and emotions.

MORAL VIRTUE

Aristotle defines moral virtue as 'a settled disposition of the mind determining the choice of actions and emotions, consisting essentially in the observance of the mean relative us, this being determined by principle that is, as the prudent man would determine it" (1106b36-07a2). Moral virtue is, first of all, a settled, relatively permanent state of the mind of a certain kind: it is a habit or disposition to choose to perform certain acts. Performing a single virtuous act does not make the agent of the act virtuous, anymore than only once paying for goods makes a man an honest man. A person becomes virtuous by repeatedly and habitually performing virtuous acts. Moreover, moral virtue lies in hitting the mean between two extremes-excess and deficiency-in regard to a continuum of action and emotion. Perfection lies in moderation, not too much and not too little, as far as our dispositions to act and feel are concerned. Courage, for example, is a mean between timidity and foolhardiness. The courageous man will act and feel in the right way, at the right time, to the right extent, in risking harm or injury, while the cowardly man will feel inappropriately and not act at all, and a rash or foolhardy man will also feel inappropriately (in a different way than the cowardly man) and plunge ahead when he should not. However, the mean is not a pure mathematical or mechanical mean between two extremes. Aristotle tells us that it is relative to us, and notes that it is many times hard to hit the mean. Sometimes the best we can do is to try to avoid the extremes or to lean toward the less faulty extreme of the two. To be generous, for example, is to give the appropriate amount, in the appropriate way, at the appropriate time and place, and to feel properly in doing so (not to do so grudgingly, for example). We should not give too much or too little. But when we are not sure about the mean, it is better to give more than less.

Aristotle also provides us with a list of specific moral virtues. Among them are courage, temperance, greatness of soul, gentleness, truthfulness, wittiness, friendliness, righteous indignation, and justice. This list of specific virtues is introduced in Book II with an explanation of their excesses and deficiencies. In relation to pleasure and pain, the excess is profligacy, the deficiency insensibility, and the mean temperance. In relation to honor and dishonor, the excess is vanity, the deficiency smallness of soul, and the mean greatness of soul. In attitudes to anger, the excess is irascibility, the deficiency spiritlessness, and the mean gentleness. In attitudes to truth, the excess is boastfulness, the deficiency self-deception, and the mean truthfulness.

INTELLECTUAL VIRTUE

The virtues of the intellect, that is, intellectual virtue, are wisdom and prudence. Wisdom (sophia ) refers to theoretical or philosophic knowledge, while prudence (phronesis ) -Aristotle does not use the term in the modern sense-refers to practical good sense-what today we many times call good judgment-which is an essential factor in the possession and exercise of all moral virtues. Prudence is good sense, the ability to decide what is appropriate in a particular situation and act accordingly. The intellect, in pursuing and contemplating the truth of what is necessary and universal, and of what is appropriate in particular circumstances, is both unique to human beings and the highest or best faculty of human beings. The intellect, then, is the best part of the soul, according to Aristotle, and since the intellect possesses its own excellence, its virtue is the highest virtue. The crowing achievement of the good life is thus contemplation.

THE HAPPIEST LIFE

Aristotle thinks that the happiest life is the life of activities in accordance with the highest of the virtues. This is the life of the intellectual virtues. Such a life is complete and self-sufficient, for seeking, gaining, and contemplating wisdom is an end itself and has its own intrinsic pleasure. People can engage in this activity without any colleagues, and more than any other activity, can practice it free from fatigue. In addition, the enjoyment of this activity and its fruits is the purest and strongest enjoyment. The life of the intellectual virtues satisfies the requirements of the supreme good to the highest degree, and is superior to the life of the other forms of virtue. Such a life is lived on a plane 'higher than the human level,' and is achieved only by the divine element in man. The life of the intellect, in short, is the happiest.

However, Aristotle does say that the life of the intellect is not completely possible for us. Being human, even people who are most engaged in the pursuit of wisdom need friends, community, health, and moderate wealth. It is impossible for us to exclusively pursue and enjoy intellectual activity. But Aristotle encourages us to aspire to the best. He says that 'we must do all we can to make ourselves immortal.' (1177b26) Is Aristotle here telling us to pursue an extreme, being divine, which we cannot reach? No, he is simply telling us to live according to the most precious and divine part of us. That part is the intellect, and that life is the best and happiest.

FRIENDSHIP

Friendship is an important value to the great majority of people, and Aristotle understood well just how important and, indeed, necessary, it is. Books VIII and IX are devoted to it.

Nowadays the word 'friend' has a narrower sense than it did in ancient Greece. People are by nature social, Aristotle thought, and philia , the relation Aristotle examines in friendship, includes any impetus a person has toward associating with others. Friendships thus can be and are of different kinds, depending on the aim or object of the friendship. Three are especially important for Aristotle: pleasure, utility (use), and goodness. The first two, however, are only accidental friendships, according to him, for they are unstable and easily fall apart.

Friendship is a virtue, a habit of rational choice. A person wishes to do, and does, what he believes to be good for his friend, and does so for his friend's good, not his own. Friends wish to be together, and friends share the same tastes and experience each others' joys and sorrows, triumphs and defeats, as their own. A friend is a second self; the relation of a person and his friend is very similar to the relation a good man has to himself. Friends pursue the same ends-good ends-for their own sake, and would not change who they are even if they could. A good man is pleased to live with himself, as are friends with each other.

Aristotle's elaborate comparison of the relation of a good man to a friend to the relation of a good man to himself is somewhat egoistic, but not overly or repugnantly so. Generously read, Aristotle is saying that in friendship, the self is extended beyond one's own body, and so the happiness or misery of another becomes one's own. Friendship is a bridge which, in effect, makes two lands one, while all the while they are, as we know, two. In addition, Aristotle emphasizes the more active, the more giving, the more loving aspects of friendship than the more passive-that is, than the getting, than the being loved-and he repeatedly speaks of doing things for the sake of the friend, not one's own sake.

PLEASURE

It is important to understand the relation between pleasure and happiness in Aristotle's philosophy. Aristotle's is an ethics of virtue (not principle), and a virtuous person does not just feel the right way, and do the right thing, at the right time, at the right place, to the right extent; he or she also takes pleasure in virtuous action. That is why, although the aim of virtuous action is not pleasure for the agent, it's still true, Aristotle says, that the virtuous person has the most pleasant life.

Aristotle is no hedonist, in other words, for a hedonist identifies the good with pleasure, and Aristotle thinks that is a confused and mistaken view. It is confused for at least two reasons. First, actions do not aim at pleasure but at something else-solving a mathematics problem, say, or getting to the other side of town. Pleasure may accompany activities such as examining and thinking about the premises of a mathematics problem, or driving in the direction of the other side of town, but pleasure is not the aim of those activities any more than casting a shadow is the aim of walking on a sunny day. Second, "pleasure" is not what hedonism apparently takes it to be, the name of a single sensation which is related to different actions the same way that a single effect-say, death-is to many different causes-say, being poisoned, being shot, being stabbed, or having a stroke. Rather, the pleasure of an activity such as playing ping-pong is internally related to that sort of activity, and cannot be separated from it. Similarly, the pleasure of reading an exciting novel is internally related to it, and cannot be separated from it. It follows that there is no one state, pleasure, gotten at-or caused by-many different actions, and that pleasure is not a single sensory state, a sensation. There are as many kinds of pleasure as there are kinds of activity, and, Aristotle says, the worth of a pleasure is to be judged by the worth of the activity, not vice-versa, as the hedonist would have it.

But if hedonism is false, what is the relation between happiness, the supreme good, and pleasure? Aristotle says that happiness is to pleasure as health is to the blush on the cheek of youth. Heath is a good, the proper state of the body functioning as a body, and it is not a subjective state like enjoying or liking. A blush on the cheek of youth is not the aim of eating well, sleeping well, exercising, or the like; health, a virtue of the body, is. The blush is a kind of added side-benefit, a good-for pleasure is a good-that naturally arises from the promotion of health; and it is also a sign or symptom of health. The same relation hold between happiness and pleasure: virtuous activity typically has pleasure as a kind of side-effect-in fact, Aristotle says that a virtuous person naturally takes pleasure in virtuous activity-and pleasure is a sign or symptom that the person who engages in virtuous activity is fully virtuous. Pleasure, however, isn't the end or purpose of virtuous activity-virtuous activity is engaged for its own sake-and virtuous activity without pleasure is possible (as is pleasure without virtuous activity).

The topics discussed above are but a small few of those covered in the Nicomachean Ethics . Like all great philosophy, the Nicomachean Ethics deserves close and recurring study. But close and recurring study of it will be, if Aristotle is correct, part of a life that could be the best of lives.

Hye-Kyung Kim is part of the Department of Philosophy at the University of Wisconsin at Green Bay.