Morality tells us how we ought to behave, if we want to do the right thing. But is there a reason why we ought to be moral in the first place? Both Plato and Kant believed that morality is dictated by reason and so a fully rational person is automatically a moral person too. But how can we derive morality from reason? Isn’t it possible to be a rational but amoral or even immoral person? John and Ken walk the line with James Sterba from the University of Notre Dame, author of From Rationality to Equality.