This book is about two related subjects. One concerns the variety and range ofaccounts of human nature that have emerged in the last three thousand years. Almost all of these accounts are philosophical, and it is striking how many philosophers have embedded such accounts in their work. The other subject is the very concept of "human nature," which is part of the basic set of ideas that most people have, including most people who have never studied philosophy. It provides an interesting case of common sense thinking that turns out to enter the same territory as philosophy.