This book offers a fresh approach to the problem of the philosophy of nature. Written by a specialist whose competence is unquestionable, the book aims at simplicity without sacrificing profundity. The important problems raised by modern science with respect to the philosophy of nature are treated in such a way as to be understandable even to those whose knowledge of physical science is rather limited. Careful considerations is given to historical factors which have in the past so often led to confusion of philosophy and science and which even in the present time remain a source of conflict between scientist and philosophers.