How ought we to live? What really exists? How do we know? This lively and engaging book is the ideal introduction for anyone who has ever been puzzled by what philosophy is or what it is for. Edward Craig argues that philosophy is not an activity born from another planet: learning about it is just a matter of broadening and deepening what most of us do already. He shows that philosophy is no mere intellectual pastime: thinkers such as Plato, Buddhist writers, Descartes, Hobbes, Hume, Hegel, Mill and de Beauvoir were responding to real needs and events - much of their work shapes our lives today and many of their concerns are still ours.