This book, a development of his Tarner Lectures given in 1919, is one of Alfred North Whitehead's most important contributions to natural philosophy. His first concern is with the fundamental problems of substance, space, and time; and the most interesting part of his discussion is, perhaps, his criticism of Einstein's method of interpreting results, and the alternative development of his own well-known theory of the four-dimensional 'Space-Time manifold'. Although this book was first published over a generation ago, and the characteristic approach of philosophers to the problems of nature has changed considerably in the intervening period, The Concept of Nature has never ceased to deserve their careful attention. When the book first appeared, A. E. Taylor, writing in Mind, said 'The Concept of Nature is a great contribution to Naturphilosophie, far the finest contribution, in my own judgement, yet made by any one man'; J. E. McTaggart in The Cambridge Review called it 'one of the most valuable books on the relation of philosophy and science which has appeared for many years', adding 'I am sure the study of this book will benefit metaphysicians. I venture to believe that it will benefit men of science.'