A new translation of one of the cornerstones of Western philosophy. Always passionately interested in natural phenomena, Aristotle eventually dissented from Plato's idealist premise that what we perceive is just a pale reflection of the true reality. is Aristotle's first mature statement of his own philosophical understanding of reality. An extraordinary synthesis, integrating the natural and rational aspects of the world, Aristotle's probes some of the deepest questions of philosophy: What is existence? How is change possible? What makes something the same thing at different times? Are there things that must exist for anything else to exist at all? Furthermore, with his notion of "substance" and his associated concepts of matter and form, essence and accident, and potentiality and actuality, Aristotle laid the foundations for Western speculative thought on the nature of reality. Hugh Lawson--Tancred's translation achieves a read-ability absent from earlier versions, and in a stimulating introductory essay he highlights the central themes of one of philosophy's supreme masterpieces.