'Simon Duffy's book is an outstanding study of Gilles Deleuze's interpretation of Spinoza. Its guiding thread is the "logic of expression" that Deleuze extracts from Spinoza, and which plays an important role in Deleuze's own philosophy of difference. Along the way, however, Duffy examines an impressively wide array of critical topics, including Hegel's (mis)reading of Spinoza, the problem of the infinite and the metaphysics of the differential calculus, the theory of distinctions, Deleuze's "intensive" conception of modal existence, Duns Scotus' doctrine of univocity, and Deleuze's relation to other French commentators such as Pierre Macherey and Martial Gueroult. This is a rich and erudite work that will repay many re-readings. Highly recommended.' Daniel W. Smith, Department of Philosophy, Purdue University, USA 'This is a remarkable book, written with clarity and elegance on a difficult subject. It demonstrates the centrality of Spinoza in the construction of Deleuze's philosophy and, conversely, the necessity of a Deleuzian concept of "difference" in order to understand the originality of Spinoza's ontology. In the end we realize that, through these symmetric readings, Simon Duffy has himself contributed to the formulation of a "speculative logic" of quantities and intensities, that bridges the gap between a mathematics of variations and an ethics of individual powers. With this interpretation Duffy will establish his reputation as a major participant in contemporary philosophical debates.' Etienne Balibar, Emeritus Professor of Philosophy, University of Nanterre 'This book is an important contribution to the understanding of the philosophies of Deleuze and Spinoza. Simon Duffy displays an impressive mastery of material drawn from the history of mathematics and the history of philosophy in providing a rigorous and informative account of the nature and sources of Deleuze's differential logic. He shows how this logic informs Deleuze's reconstruction of Spinoza's metaphysics in Expressionism in Philosophy: Spinoza and how it differs from that of Hegel. This is essential reading for anyone interested in the metaphysics of difference.' Professor Paul Patton, University of New South Wales, Sydney, Australia
