'This book is both a fine introduction to the metaphysics of Descartes, Spinoza and Leibniz and a rich, wide-ranging study of the interaction between physics and metaphysics in the seventeenth century.' - Kenneth P Winkler, Wellesley College

This book introduces student to the three major figures of modern philosophy known as the rationalists. It is not for complete beginners, but it is an accessible account of their thought. By concerning itself with metaphysics, and in particular substance, the book relates an important historical debate largely neglected by the contemporary debates in the once again popular area of traditional metaphysics. in philosophy.