Since Socrates, philosophers have asked: Why be moral? Plato thought it was knowledge. People do wrong only through ignorance. Aristotle thought this implausible. We often suffer from akrasia, weakness of will. So we become good people the way we become good tennis players or violinists, through practice until the behaviour we aspire to becomes natural and instinctive. Being moral means acquiring the habits of the heart we call virtue. In
