To mark the anniversary — one hundred years since his birth — of Fridrikh Rafailovich Filippov, a Soviet sociologist who made a great contribution to the development of research on social mobility and education in our country, we are posting on the pages of Russian Sociological Review a fragment of his last major book, based on materials whose uniqueness is not inferior to the author's notorious analytical intuition. The book was published at the end of the Soviet period in the development of both the country and the sociology associated with this period. The book, made with all scientific care, remains a document of the epoch, which we look back on more and more often after thirty-five years.