The term 'ideology' was coined by the French philosopher Destutt de Tracy at the beginning of the nineteenth century to mean 'the science of ideas', but it did not enjoy widespread use until the posthumous publication of Marx and Engels' The German Ideology in 1927. They defined ideology as 'false consciousness', that is a distortion of reality - the reality being the class struggle, the distortion the prevailing ideas of the ruling class. This led Karl Mannheim (1936 ) in Ideology and Utopia to develop his theories about the sociology of knowledge, that is, ideas about ideas and systems of thought in particular social contexts. He came to define ideology as 'styles of thought' about social phenomena and therefore posited that Marxism itself was an ideology. Mannheim further argued that ideologies may range from a limited or particular ideology, such as the ideology of small businessmen, to a total ideology, or Weltanschauung, that sought to explain everything.