One of the major philosophical texts of the twentieth century, Process and Reality is based on Alfred North Whitehead’s influential lectures that he delivered at the University of Edinburgh in the 1920s. In it, he propounds a philosophy of organism (or process philosophy), in which the various elements of reality are brought into a consistent relation to each other. It is also an exploration of some of the preeminent thinkers of the seventeenth and eighteenth centuries, such as Descartes, Newton, Locke, and Kant.