'The Philosophy of Category Theory comes of age with Spinoza, Peirce and Deleuze, understood through functors, presheaves and adjunctions. A compelling use of nearly 50 diagrams supports a deep understanding of structure, variation and difference. Gangle introduces a new, needed voice for the provocative "visual turn" of the twenty-first century.' Fernando Zalamea, Universidad Nacional de Colombia, author of Synthetic Philosophy of Contemporary Mathematics Add second endorsement: 'This exceptionally useful text explores the rich and complex contours of the relation between category theory and philosophy with admirable clarity. In the process it develops a diagrammatic philosophy of immanence as an exemplar of this relation, and demonstrates the value and remarkable potential of category theory for philosophy.' Simon B. Duffy, Yale-NUS College, Singapore A renewal of immanent metaphysics through diagrammatic methods and the tools of category theory Spinoza, Peirce and Deleuze are, in different ways, philosophers of immanence. The methodological questions raised by a commitment to immanence are addressed here by Rocco Gangle in terms of how diagrams may be used both as tools and as objects of philosophical investigation. This book integrates insights from Spinozist metaphysics, Peircean semiotics and Deleuze's philosophy of difference in conjunction with the formal operations of category theory. Category theory reveals deep structural connections among logic, topology and a variety of different areas of mathematics, and it provides constructive and rigorous concepts for investigating how diagrams work. Gangle offers a basic introduction to the methods of category theory from a philosophical and diagrammatic perspective allowing philosophers with little or no mathematical training to come to grips with this important field. This coordination of immanent metaphysics, diagrammatic method and category theoretical mathematics opens a new horizon for contemporary thought. Rocco Gangle is Associate Professor of Philosophy at Endicott College, USA, and co-director of the Center for Diagrammatic and Computational Philosophy. Cover image: Rocco Gangle Cover design: [EUP logo] www.euppublishing.com