This book, written by the famous American physicist David Bohm, is devoted to the most pressing philosophical problems of modern physics. It focuses on clarifying the role played by causality and randomness in the physical laws of the microworld. This question is considered from the broadest perspective and is actually solved by Bohm at the level of a more general problem about the possible forms of the physical laws of both the microworld and the macroworld. Unlike earlier studies of these philosophical and physical problems, Bohm’s book reflects the fierce struggle that has developed in recent years between proponents of new interpretations of the phenomena of the microcosm and defenders of the orthodox interpretation of quantum mechanics in the spirit of the principle of complementarity. The book presents not only a detailed criticism of the philosophical and physical positions of the Copenhagen school, but also the response of the proponent of the causal interpretation of quantum theory to the objections of adherents of the concept of complementarity.