Masamichi Shimmei was the first one in Japan who wrote the outstanding 'History of Sociology', and it was well worthy of his wide erudition. His sociological history took a general view of the world sociological development from his original basic theory (Handlungszusammenhang) constructed in the early stage of his academic life. His method of sociological history is to understand the sociological theory and social thought in their mutual relations, and this idea was gradually consolidated in his later years. This very method of Shimmei's is one which is very alike to the concept of the 'Sociological Thought' or 'Sociology of Sociology' - the object of recent attentions in Europe and the United States of America. Yet one cannot say this method is realized successfully in his sociological history. And when he takes the standpoint of sociological thought, it is inevitably contradictory to his other arguments, especially his critique to the medium concept of Karl Mannheim's 'geistige Schichten', which he enthusially insisted in his early works. Thinking of his long academic life, it is no wonder that there is some inconsistency of his position, but I believe it is very important to clarify those points in order to understand the relation between Shimmei's position in 'sociology of knowledge' and his systematic theory, as well as his attitude to the Marxism.