The present work attempts, first, to sum up the studies in this field of both the author himself14 and of other Soviet specialists in epistemology, and, second, to analyse a number of aspects of the given problem that are of a general and fundamental nature and at the same time have not been sufficiently studied in Soviet literature. We shall try to specify and consider here the mam types of conceptions of the cognitive relation, of the subject-object relationship, i.e., the various modes of formulation and discussion of the basic epistemological themes. Our objective is a clear formulation of those conditions of studying this problem which ensure the fruitfulness and scientific quality of the theoretical quest on the basis of the dialectical materialist epistemology and at the same time accord with the specificity of the cognitive situation created by the development of modern science.Vladislav Lektorsky, D. Sc. (Philosophy), is head of the Epistemological Sector, Institute of Philosophy of the USSR Academy of Sciences. His scholarly Interests range wide, covering dialectical logic, the methodology of science, history of philosophy, psychology of knowledge, etc. He has published scores of papers and books on these subjects that were highly appreciated by scholars. A number of his papers have appeared in foreign scientific publications.Translated from the Russian by Sergei SyrovatkinDesigned by Vladimir BissengalievMany thanks to Daniel Baker for the original scans.Note: Some pages are warped.