Various usages of the term “ideology” run through the literature of social science. The theorists of the Enlightenment identified ideology with the search for truth and the dispelling of illusions; it was a “science of ideas.” Karl Marx offered a different conception, arguing that ideology was “false consciousness,” or the illusion created by the experience of a social class in a capitalist society. True consciousness, he believed, would come only through class struggle, in which workers would begin to understand their alienation from the process of capitalist production. Karl Mannheim relied on Marx's interpretation but distinguished between a particular conception of ideology as “more or less conscious disguises of the real situation” and a more inclusive conception of ideology as “a concrete historical-social group, e.g., of a class.”

Contemporary social science views ideology as a set of values, beliefs, expectations, or prescriptions. Ideologies often are associated with industrialization and the economic and social problems that may ensue. Sometimes ideologies are defined in an unrealistically optimistic context, whether a free market or classless society. Thus, it is suggested, ideologies are becoming exhausted in the modern world. With technology, there may be stability and consensus so that ideologies reach an end. This view has been challenged by many writers. Joseph La PaJombara, for example, argued that many ideologies deserve study, and David Apter considered the study of ideology more important than ever.