Roger Woolhouse 
Descartes, Spinoza, Leibniz [PDF ebook] 
The Concept of Substance in Seventeenth Century Metaphysics

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.