‘How should one live?' It is not a trivial question, Socrates says. Perhaps uniquely among animals, we human beings not only act, we also consider how we should act. We think that there are better and worse ways of acting, we reflect on our experience of making mistakes, and try to improve things. Much of this, of course, relates to our own self-interest – meeting our needs, successfully achieving our personal goals, and so on. But that is not all. We are social creatures, we live together, and our lives and actions affect the lives and actions of other people. How should we relate to one another, how should we treat one another? We are concerned not only for ourselves, but for other people as well, and how other people treat us is critical to our own happiness. How should each of us live so that each of our lives goes ‘best’? What is ‘good’ in life and how may we go about trying to attain it?