The next book in the “Library of Russian Philosophical Thought” series introduces the reader to the epistemological ideas of the outstanding Russian philosopher Sergei Alekseevich Askoldov (1871 – 1945), professor at St. Petersburg University. The collection includes works created by the thinker in the late 10s - 20s. XX century, most of which have not been reprinted since that time.S. A. Askoldov continued the development of the concept of “panpsychism”, created by his father, the philosopher A. A. Kozlov, laid the foundation for the original personalistic theory of knowledge and made a significant contribution to the ideological polemics with the “antipsychological” direction in epistemology and logic. The book is addressed to scientists and teachers and students of humanities, as well as anyone interested in the history of Russian philosophy, current problems of the theory of knowledge and methodology.