The aim of this book is to give an introduction to Western philosophy through its past, both distant and more recent, and to serve as a useful work for more advanced students of philosophy. The subject of philosophy is presented in this book by studying the thought of major philosophers and by concentrating on what are generally regarded as the central areas of philosophy: the nature of philosophy itself, the theory of knowledge (epistemology) and the essential nature of reality (metaphysics). It is hoped that this work will satisfy the curiosity of those who want to understand what philosophy is and will provide a key to further study of philosophy and philosophers. To aid the reader in further study an extensive annotated bibliography is included, which serves as a guide primarily to works by and about the philosophers considered in this book, although it also includes reference to more general works in philosophy.

The various chapters and sections within the book can be usefully read in isolation, since they are relatively autonomous, although there is an additional cumulative beneficial effect that results from reading right through the book in order.

It is impossible to deal with every controversy over interpretation. However, every attempt has been made to be clear and accurate. The general approach to each philosopher considered is to present an account that tries to make their views hang together convincingly, rather than subject them to intense critical dissection. There are, however, some critical observations which naturally arise from exposition.