Della Rocca concentrates on two problems crucial to Spinoza's philosophy of mind: the requirements for having a thought about a particular object, and the problem of the mind's relation to the body. He contends that for Spinoza these two problems are linked and thus part of a systematic philosophy of mind.

"A very rigorous, sophisticated and subtle treatment of central issues in Spinoza's philosophy of mind and knowledge....Della Rocca puts forward interpretations which are likely to be the subject of discussion among Spinoza for some years to come. In general, Della Rocca shows himself to be an original, subtle, and often brilliant expositor of Spinoza."--Nicholas Jolley, University of California, San Diego "It will be a classic--'must' reading for Spinoza scholars, historians of philosophy in general, advanced students of the history of philosophy, and anyone interested in early mdoern cognitive psychology. It is one of the most exciting works in the history of philosophy that I have read in a long time....It deserves the widest possible readership."--Don Garrett, University of Utah "A very rigorous, sophisticated and subtle treatment of central issues in Spinoza's philosophy of mind and knowledge. Della Rocca puts forward interpretations which are likely to be the subject of discussion among Spinoza scholars for some years to come. In general, Della Rocca shows himself to be an original, subtle, and often brilliant expositor of Spinoza."--Nicholas Jolley, University of California at San Diego "This book will be a classic--'must' reading for Spinoza scholars, historians of philosophy, advanced students of the history of philosophy, and anyone interested in early modern cognitive psychology. It is one of the most exciting works in the history of philosophy that I have read in a long time." --Don Garrett, University of Utah "The arguments are presented with impressive clarity and in great detail....the book is a significant contribution to the literature on Spinoza's metaphysics ad epistemology, and should be read by anyone with a serious interest in its historical subject or in the two perennial philosophical problems on which it focuses....[an] ambitious, stimulating book."--The Philosophical Review