This article is devoted to the great Russian philosopher A.F. Losev (1983—1988) and his place in the history of evolution of Russian psychology. Losev’s attitude to his scientific advisor at the Institute of Psychology, G.I. Chelpanov, as well as to the ensuing discussions between G.I. Chelpanov and K.N. Kornilov in the 1920s are being considered. Attention is focused on the generation of Losev’s interest in psychology, and consequent transformation of the works of the 1910s directly devoted to psychological problems (“Criticism of modern functional psychology”, “Critical review of the basic teachings and methods of the Würzburg School”, “Research on philosophy and psychology of thinking”). The evolution of psychological views of the thinker is described – from the enthusiasm of his student years for experimental and functional psychology to the construction of psychology based on the “genetic method”, and then, in the late 1920s, to the Platonic-patristic psychology outlined in the “Supplement to the Dialectics of Myth”. Proceeding from the new European psychology, including F. Brentano and E. Husserl guided by Thomas Aquinas (and through him by Aristotle), Losev builds his “absolute mythology”, based on the opposite tradition going back to neoplatonism, Dionysius the Areopagite and Nicholas of Cusa. The article shows how in the 1920s Losev developed a new, sociological, vision, the belief that every being (physical, physiological, psychological and naturalistically-causally-sociological, etc.) “is, in comparison with social existence, a pure abstraction”, and this does not lead to the rejection of “materialistic idealism” and “absolute mythology”. This sociological stand promotes the description of “relative mythologies” (collective psychology, social “myths”). In the 1930s—1940s, knowledge gained in the walls of the Institute of Psychology as well as Losev’s habit of self-observation and reflection about his own experiences contributed to the writing of psychological musical-philosophical prose, where Losev conceptualizes problems also addressed in his “octateuch” of the late 1920s.