What we do in our dealings with other people makes some of us just, some unjust. What we do in terrifying situations, and the habits of fear or confidence that we acquire, makes some of us brave and others cowardly. The same is true of situations involving appetite and anger; for one or another sort of conduct in these situations makes some temperate and mild, others intemperate and irascible. To sum it up in a single account: habit results from the repetition of similar activities. — Aristotle, Nichomachean Ethics