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Throughout his career, Mannheim sought to establish relationships between structural categories and modes of thought. Thus, he looked at classes, sects, generations, and parties to conceptualize differences in their worldviews. In Ideology and Utopia, for example, he identified different forms or ideal types (see Max Weber...) of the "utopian mentality." For example, early religious sects (such as the Anabaptists) joined with other oppressed groups in the "spiritualization of politics." Their revolutionary conception of society was fixed on the establishment of a  millennial kingdom on earth.

The bourgeois thinking of the Enlightenment also struck at the waning power of the aristocracy. They represented a socially ascendant class whose utopian mentality took the form of a "liberal-humanitarian" ideal. This ideal featured a reasoned form of progress, and it was advanced by the middle stratum of society. This stratum, in turn, was disciplined by a "conscious self-cultivation" and sought justification in a new ethics and intellectual culture that undermined the world of the nobility.

Other forms of utopian mentality include the "conservative mode," bent on controlling the anarchism of "inner freedom" that threatens the utopian dream. The last is the "socialist-communist" mode," which locates human freedom in the breakdown of capitalist culture ([1936] 1968:247). Given this range, it is clear that thought which is utopian in one context may be ideological in another. 

Despite this promising delineation of ideal types of utopian thought, Mannheim proved historically imprecise in associating ideas and social position. This problem can be generalized to his work as a whole. Put clearly, Mannheim was routinely content to interpret knowledge from the vantage point of idealist philosophy. He struggled with the context of ideas and their interrelations within the structure of an overall system of thought. When he introduced the larger question of structure, he did little more than claim that knowledge is bound up in social position. When he dealt with specific classes or movements, he was content to use them more as illustrations of how thought systems differ. He seldom specified the real, material conditions that give rise to ideological and utopian visions.