The Scientific Biography of P.Ya. Galperin: Stages of Life and Creative Work.

Background: This article is dedicated to the 120th anniversary of the birth of Piotr Yakovlevich Galperin (1902-1988), an outstanding Soviet psychologist, the author of an original psychological concept and scientific school, and an organizer of psychological science.

Objective: To reconstruct the main stages of the scientific biography of Piotr Yakovlevich Galperin.

Results: The paper demonstrates the internal logic of P.Ya. Galperin's developing scientific views in creating the theory of stage-by-stage formation of mental actions and concepts, which analyzes the process of formation of the main components of mental activity and develops a system of conditions for transforming an objective action into a psychological phenomenon.This biography is based on Galperin's publications and speeches, memoirs of associates and family members, and numerous archival materials.All the periods of Galperin's life are presented, reflecting his participation, starting from the mid-1920s, in scientific and scientific-practical events. Particular attention is paid to Galperin's work at M.V. Lomonosov Moscow State University (MGU): 55 years of Galperin's professional and personal life (from 1943 until his death in 1988) were associated with the Philosophy Faculty, and then with the Psychology Faculty.

Conclusion: The importance of preserving P.Ya. Galperin's scientific legacy is shown and steps taken in this direction are indicated.