Kolman's philosophy has been, throughout the major part of his life, distinctly Stalinist. After he had been released from prison and after the 20th Congress of the Communist Party of the U.S.S.R. (1956), he became critical of Stalinist dogmatism in philosophy and politics. Although his philosophic thought underwent some — if only minor — changes, Kolman remained entirely within the framework of Marxist philosophy, retaining its foundations, as contained in the writings of "the classics' of Marxism — Marx, Engels and Lenin.