This book is the first part of a task which has occupied me for many years, and which I hope some day to complete with a critical and historical account of the sources of Spinoza's thought and its influence upon later thinkers. This volume, however, forms a whole by itself and attempts what seems the most pressing need in connection with Spinoza's philosophy, namely, an exposition of his ideas in their mutual relations, and and account, more or less systematic, of his view of the world and man. The aim of this book therefore is not to furnish either a criticism or a defence of his teaching, but only to contribute to the understanding and elucidation of it. The only passages which may appear polemical are those in which, at a parting of the ways, it is pointed out what is, and what is not, the road which Spinoza takes. A candid reader will, however, distinguish between the assertion that a writer's view is this and not that, and an attack upon his critics or an advocacy of his opinions.