Three separate ethical treatises are included in the Aristotelian Corpus, the Magna Moralia, the Eudemian Ethics and the Nicomachean Ethics. Of these the Magna Moralia is far from certainly authentic. Some scholars consider it an early work, composed while Aristotle was still much influenced by Plato, but it is more usually thought to have been written by one of Aristotle's pupils. Of the two other ethical treatises the Eudemian Ethics is generally held to be the earlier and it is useful both for the additional evidence it provides concerning some of Aristotle's ethical theories and more especially for the light it throws on their development. Our main source for his mature moral philosophy is, however, the Nicomachean Ethics, and it is with this that I shall be chiefly concerned in this chapter.

The plan of the ‘Nicomachean Ethics’

This is one of the most coherent and systematic of Aristotle's treatises and it is probably the easiest and most rewarding of all the major works for the student to tackle first. Unlike the Physics and the Metaphysics, which are collections of books that are often quite loosely connected to one another, the Nicomachean Ethics forms a coherent whole. Aristotle defines the subject and states the problem in book i. Books ii to v deal with moral virtue, first in general, then, after a discussion of choice and responsibility, in detail. Book vi deals with intellectual virtue, vii with moral weakness.