Nicomachean Ethics — themes & analysis

Aristotle opens with one of the most consequential sentences in Western philosophy: every art, every branch of knowledge, every action and choice seems to aim at some good. Some ends are pursued for the sake of further ends — money for comfort, comfort for leisure. If this regress had no terminus, every choice would be empty. So there must be a final good, sought for its own sake and never for anything beyond it. Aristotle calls it eudaimonia — translated weakly as happiness, more accurately as flourishing or living well.

To say what eudaimonia consists in, Aristotle gives the function argument. Each thing has a characteristic activity that defines what it is to be that thing well: a knife in cutting, an eye in seeing, a harpist in harp-playing. Does a human being have such an activity? He does, Aristotle argues, and it cannot be mere life (shared with plants) or perception (shared with animals). It must be the activity of the rational part of the soul. The good for a human being is therefore the activity of the soul in accordance with virtue — and if there are several virtues, in accordance with the best and most complete, over a complete life.

The argument has been attacked from every angle for two thousand years. The basic move — that the good for a creature must be discovered by attending to the kind of creature it is — has survived every attack. It is the move every later virtue ethics depends on: Aquinas, Anscombe, MacIntyre. And the recognition that eudaimonia is not a feeling but an activity has shaped moral philosophy in ways that the rival Benthamite tradition still struggles to absorb.

Where to follow it: Book 1 (the function argument, happiness and its conditions), Book 10 (the final answer — contemplation vs. the active life).

Book 2 contains the practical heart of the Ethics. Moral virtue, Aristotle says, is not given by nature; nature gives only the capacity to develop it. It comes about by habituation. We become just by doing just acts, temperate by doing temperate acts, brave by doing brave acts. As the builder becomes a builder by building, as the harpist becomes a harpist by playing, so the moral agent becomes virtuous by acting well — or vicious by acting badly. The early years of life are decisive, because habit forms what reason will later have to live with.

From this comes the doctrine of the mean. Each moral virtue is the median state between two vices: one of excess and one of deficiency. Courage stands between cowardice (deficiency) and rashness (excess). Generosity stands between stinginess and prodigality. Truthfulness stands between false modesty and boasting. But the mean is not the arithmetic middle; it is the right amount in the right matter toward the right person at the right time for the right reason — a list Aristotle himself admits is hard.

There is no formula. The person of experience and practical wisdom finds the mean by perception, the way a doctor finds the right dosage. And Aristotle adds, with characteristic precision, that some actions and feelings do not admit of a mean at all. There is no right amount of murder, theft, or adultery; the names already imply the wrong. The doctrine of the mean is not a recipe for moral mediocrity. It is the recognition that virtue is calibrated to circumstance, and that wisdom is the calibration.

Where to follow it: Book 2 (virtue as habit; the doctrine of the mean introduced), Book 3 (courage and temperance examined), Book 4 (further moral virtues: generosity, magnanimity).

Book 6 introduces a distinction ordinary moral talk usually slurs: the distinction between intellectual virtues and moral ones. Among the intellectual virtues, the one that organises the practical life is phronesis — practical wisdom. Phronesis is not cleverness, which is the ability to find means to any end, good or bad. It is the disposition to deliberate well about what is good for a human being overall and to act on the deliberation. It is what makes a virtuous person virtuous in actual cases.

A person who has the right values but cannot perceive what the present situation requires will fail. A person who can perceive but lacks the right values will use that perception against the good. Phronesis joins the two. It is acquired only by experience, which is why young men, Aristotle famously observes, may be excellent mathematicians but cannot be good moral philosophers: geometry can be learned without time, but ethics cannot. This is also why the Ethics is not addressed to the young. The intended reader already wants to be good and is trying to understand the activity they are already engaged in.

Alongside phronesis, Book 6 describes scientific knowledge (of necessary truths), technical skill (of things that can be otherwise), and nous (intuitive understanding of first principles). The intellectual virtues together constitute the full rational life. What Book 6 establishes is that moral virtue alone is insufficient: without the intellectual perception of what the situation requires, the virtuous disposition cannot find its proper expression.

Where to follow it: Book 6 (phronesis and the intellectual virtues), Book 2 (where the general need for judgment is first stated).

Book 7 takes up the puzzle that Plato had treated as a contradiction: akrasia, weakness of will. How can a person know that an action is wrong and do it anyway? Socrates had denied that this happened at all — to know the good, he argued, was necessarily to do it, so apparent cases of weakness of will were really cases of ignorance. Aristotle insists that akrasia does happen; it is a fact of moral experience that requires explanation rather than denial.

His explanation is careful. The akratic agent does possess the relevant general knowledge — "adultery is wrong" — but in the moment of temptation, passion overrides the activation of that knowledge. The person acts on a particular judgment ("this pleasure is available now") while the general principle remains notionally in place but functionally idle, like a drunk who recites theorems without understanding them. The knowledge is present but not operative.

The discussion is one of the most psychologically precise passages in classical philosophy, and the problem of akrasia has continued into modern philosophy of action without being resolved. What Aristotle does here is install the question permanently on the agenda — demonstrate that the phenomenon is real, that it requires a distinction between having knowledge and using it, and that its existence tells us something important about the structure of human motivation. He also distinguishes the akratic person from the vicious one: the akratic person knows they are doing wrong and regrets it; the vicious person does not.

Where to follow it: Book 7 (akrasia, its kinds and explanation), Book 3 (voluntary action and responsibility — the foundation).

Books VIII and IX occupy more space than any other single topic in the Ethics, and they make a claim that still surprises readers raised on the assumption that morality is fundamentally about strangers. No one would choose to live without friends even if they had every other good. Friendship, Aristotle says, is necessary for life — it is either a virtue or implies one — and his analysis distinguishes three kinds.

Friendships of utility are based on what the friends can get from each other — common in commerce and politics — and last only as long as the usefulness does. Friendships of pleasure are based on the enjoyment one finds in the other's company — common among the young, who live by feeling. Both kinds are real and have their place, but neither is friendship in the highest sense. The third kind, friendship of virtue, is between two good people who love each other for what they are rather than for what they provide. It is rare, slow to form, and durable, because virtue is durable and the friend is loved as a second self.

Aristotle's deepest claim — often missed — is that this third kind of friendship is the precondition for fully exercising one's own virtue. Self-knowledge is difficult; the virtuous friend is the mirror in which you see yourself most clearly. To act well is hard alone; the friend shares the activity. Books VIII–IX are Aristotle's most personal stretch of writing: a man who has had great teachers and watched political men grow corrupt, the weight of long observation in every line. It is the section of the Ethics that has aged best.

Where to follow it: Book 8 (three kinds of friendship), Book 9 (friendship and self-knowledge; dissolving bad friendships).