Substance: Its Nature and Existence is one of the first accessible introductions to the history and contemporary debates surrounding the idea of substance. An important and often complex issue, substance is at the heart of Western philosophy. Substances are distinguished from other kinds of entities such as properties, events, times, and places. This book investigates the very nature and existence of individual substances, including both living things and inanimate objects. Taking as their starting point the major philosophers in the historical debate - Aristotle, Descartes, Spinoza, Locke, and Hume - Joshua Hoffman and Gary S. Rosenkrantz move on to a novel analysis of substance in terms of a kind of independence which insubstantial entities do not possess. The authors explore causal theories of the unity of the parts of inanimate objects and organisms; contemporary views about substance; the idea that the only existing physical substances are inanimate pieces of matter and living organisms, and that artifacts such as clocks, and natural formations like stars, do not really exist. Substance: Its Nature and Existence provides students of philosophy and metaphysics with an introduction to and critical engagement with a key philosophical issue.