Aristotle regards virtue as a disposition. It is possible for a good man to perform bad actions or for a bad man to perform good ones. However, he claims in book 2, chapter 3 of the Nicomachean Ethics that the good man will feel pleasure in performing a good action and pain in performing a bad one. His conduct will therefore naturally be guided in the right direction by his character.

Whether a man is good or bad depends on his virtues, not his passions. The same is true of faculties. No one is praised or blamed for passions and faculties, as they are for virtues or vices, which, according to Aristotle, are states of character rather than feelings or abilities.

Aristotle describes moral virtue in book 2, chapter 6 as "the state of character which makes a man good and which makes him do his own work well." For most types of action, there is a virtuous state of character, which lies in choosing the middle path between extremes. Both extremes, of excess and defect, are characteristic of vice, while the middle path between the two is characteristic of virtue. However, there are some types of action which are always wrong, such as murder or adultery. There is no mean in such actions, and they should be avoided altogether.

Finally, since people have different abilities, the mean may not be the same for both of them. Hence, two virtuous men may, in practice, perform different actions. The right amount of training for an experienced athlete is not the same as the right amount for a beginner.