The prevailing part of art historians, critics and theoreticians from the mid-1950s even until today feels related to the means of expression of the modernist art trends from the last decade of 19th c. until the end of 1960-s. Modernism has become a sacred text, whose complexity should be interpreted, but not criticized. Sedlmayr’s conception of art is built on moral, religious, aesthetic and political grounds, which are the very reason for the actuality of his works – both in the specialized sphere of art history and in the wider public debate on values. That is why I will analyse his structural approach mainly in relation to his anti-modern conception of art. This is the task of this study. Sedlmayr’s effort to turn art history into a “strict science” is an independent part of his scientific pursuit; it is in relation, but is not subordinate to his conception of modern art. Those publications of his are discussed but only in the specialized literature on history of the methods in humanities, while his conception against modern art acquires an exceptional popularity. Because of that reason his theoretic contribution to the study of art remains in a penumbra. I argue that Sedlmayr’s conception has the following coinciding points with the official understanding of art in the time of socialism: – A denial to estimate art with aesthetic criteria, which the ideologists of socialist realism define as formalism, and Sedlmayr as aesthetism; – In socialism art should represent a positive ideal; Sedlmayr calls this ideal “human measure”; – Art should habituate to morals; – A conviction that the modern art from the end of 19th c. on is decadent; – A criticism against the “dehumanization” of art.