Is ideology just a political pejorative term to stigmatise those whose politics are allegedly driven by faith rather than by critical thinking? Can we actually claim that we are free from ideological inclinations? Is discourse just the means of expression of a particular ideology? In order to clarify some misunderstandings about these two key concepts in the fields of social and political philosophy, political theory and cultural theory, this book traces their origins, discusses the ways in which they have been appropriated by Marxist and post-Marxist theorists, and examines the conceptual differences and similarities between them.