The prospect of writing a very short introduction to ancient philosophy has attracted and intrigued me for some time. I would like to thank Shelley Cox for her encouragement and comments, as well as Christopher Gill, Laura Owen, David Owen, and a reader for Oxford University Press. I would like to thank Cindy Holder for help with the proofs and index. Needless to say, the shortcomings rest with me. I would like to dedicate this book to the memory of my friend Jean Hampton, who I hope would have enjoyed it.