We live in an era of reforms, advisors, and experts. Thus, we are in a time when political decisions heavily depend on how much contact with reality and learning ability is involved. Social diagnoses are simultaneously weapons in the ideological struggle of parties and social movements. They exaggerate, they downplay, they simplify - and necessarily so. The relevance of Karl Mannheim's essay 'Ideology and Utopia,' first published in 1929, lies in the analysis of this dilemma between realism and rhetoric, between knowledge and the inability to gain insight in the debate over collectively binding norms. Mannheim questions the political consequences of the fact that the same world appears differently to various observers. He also asks how political rationality is possible under these circumstances.