By Joseph G. Trabbic, Crisis Magazine - I think Aristotle and St. Thomas Aquinas more or less follow the Platonic notion of virtue, but there is more they would add to the story. Yes, a virtue is what helps us to perform our ergon well, but more than this we can say that a virtue is a habit. A habit is a settled disposition to act or live in a certain way. Consequently, a virtue would be a settled disposition to act or live well as human beings, that is, to do well what characterizes us as human beings.