Ideology is a word that evokes strong emotional responses. ‘Should ideologies be ill-reputed’ examines how ideologies are perceived. For many, ideologies are associated with -isms, such as communism, fascism, or anarchism. Ideology is viewed with suspicion and ‘ism’ as a faintly derogatory term. However, ideologies offer competing interpretations of events and seek to impose a pattern on them. The influence of Karl Marx and Friedrich Engels in shaping and developing the concept of ideology is examined in more detail. Particularly the way in which they linked class and ideology, and how their ideas have influenced non-Marxists.