First published in 1952.This is Volume V of Mannheim's collected works. When Karl Mannheim died early in 1947 in his fifty-third year, he left a number of unpublished manuscripts in varying stages of completion. The present volume is the sequel to Freedom, Power, and Democratic Planning, which was published in 1950. It contains six essays which Mannheim wrote and published in German scientific magazines between 1923 and 1929: elaborations of one dominant theme, the Sociology of Knowledge, which at the same time represents one of Mannheim's main contributions to sociological theory.