Aristotle (c. 384-322 BCE)
“It is the way that we behave in our dealings with other people that makes us just or unjust, and the way that we behave in the face of danger, accustoming ourselves to be timid or confident, that makes us brave or cowardly.”
- From The Nicomachean Ethics (Bekker page 1103b) by Aristotle, translated by J. A. K. Thomson (Penguin Classics, 2004).