What it is
The Nicomachean Ethics is one of three ethical treatises associated with Aristotle (the others are the Eudemian Ethics and the Magna Moralia). Its conventional title comes from its association with Aristotle's son, Nicomachus. The work survives in ten books and belongs, on the standard view, to the period of the Lyceum.
It is the foundational treatise of what is now called virtue ethics: an inquiry into the good life and the kind of person who lives it, rather than into rules of action or rights and duties abstracted from character.
What it argues
The treatise opens by asking what the human good is, and answers in terms of eudaimonia — usually translated "happiness," more precisely something like "flourishing," "doing-and-being-well." It locates that flourishing in activity in accordance with virtue (aretē) over the course of a complete life.
The middle books develop the famous doctrine that virtues of character lie in a mean between two failings of excess and deficiency — courage between rashness and cowardice, generosity between prodigality and stinginess — and that this mean is determined by phronēsis, the practical wisdom of the person of good character in a particular situation. Book V is the classical treatment of justice (distributive and corrective); Book VI distinguishes the intellectual virtues; Books VIII–IX are the long, careful treatment of friendship that has shaped the subject in Western philosophy ever since; Book X considers pleasure and closes with the question of the contemplative life.
Why it matters for Virtue & Power
The Ethics is the platform's central reference for the meaning of virtue, the role of practical wisdom in leadership and rule, and the relation between character and action. The vocabulary it sets — virtue, mean, prudence, friendship, flourishing — is the vocabulary the classical and medieval traditions used to think about how to live.
Citing the Nicomachean Ethics
The Ethics is cited by Bekker numbers (e.g. NE 1103a). The standard Greek text remains the Bekker edition of 1831; for the editions and archives we read from, see our Sources page.