The diaries of Ia. S. Druskin (1902-1980), an existentialist philosopher and a student of N.O. Losskii, comprise a collection of his original theological and philosophical essays. Druskin received degrees in philosophy and mathematics and a conservatory diploma as a pianist. In order to save his life and avoid ideological control, he broke with professional philosophers and began teaching mathematics in Leningrad schools. He was connected with the "Obereuts" poets (Vvedenskii, Kharms, Oleinikov) and the philosopher L. Lipavskii. Druskin left behind a large archive that incorporated works on philosophy, poetics, theology, literary theory, and musicology. Part I covers the years 1928 to 1962. Part two - 1963 to 1979. Part three includes his essays, articles, and letters. Bibliographical references, chronology, index and bibliography of Druskin"s works, index of names and works mentioned in the diaries.