Karl Mannheim was born in Budapest, Hungary, but developed his academic career in Germany (in Heidelberg and Frankfurt) and England (at the London School of Economics). He was the earliest proponent of the
sociology of knowledge
, a branch of theory concerned with the influence of social context on our way of perceiving, interpreting, and forming claims about the world. Although Mannheim began his career as a philosopher with an interest in epistemology, he became increasingly fascinated by the impact of society on thought processes, with particular emphasis on culture, intellectual competition, and intergenerational dynamics. In his most influential book,
Ideology and Utopia
(1936 [1929]), Mannheim distinguished between two forms of belief systems:
ideological
systems, which seek to ensure inertia in beliefs through an emphasis on the past; and
utopian
systems, which embrace change in beliefs through an emphasis on the future. After being forced from Germany in 1933, Mannheim's writings turned toward the contemporary crisis generated by fascism, examining the role of planning and the possibility of a democratic society.