This work-written in 1908 as a militant, occasionally virulent, polemic against certain Bolsheviks who had strayed from dialectical materialism into the jungle of "Machism" and associated idealist philosophies-serves today as an invaluable example of Lenin's approach to philosophy and as a general exposition of dialectical materialism.

Lenin's breadth of knowledge shines in this text: he discusses the Marxist theory of knowledge, critiques the idealists, from Berkeley to the then current schools, and examines the contemporary "crisis" in natural science induced by new discoveries about the nature of matter and its concomitant ramifications for scientific study and questions of epistemology.

With a new foreword by Helena Sheehan, the reprint of this classic text aims to return Materialism and Empirio-Criticism to the attention of the growing number of students of Marxism in the United States, and to provide material for the study of the interrelationship between Marxist politics and philosophy.