ABSTRACT
Karl Marx used the term ideology in two interrelated senses: first, idealism and second, an apologetic body of thought. He uses the term ideology to mean not only idealism but also apologia. In the works following the 'German Ideology' and the 'Poverty of Philosophy', Marx's usage of the term ideology begins to change. He now takes apologia, which he had hitherto regarded as a consequence of ideology (understood as idealism), to be its defining feature. Although Marx increasingly used the term ideology to mean apologia, he did not stop using it in the original sense of idealism. Like Marx, Friedrich Engels used the term ideology all his life to mean both idealism and apologia. The remarkable thing is that Engels is here using the term ideology in the sense of idealism and not apologia, as becomes clear when one reads the lines that immediately follow it. Marx, then, used the term ideology to mean both idealism and apologia.
