Revolutionary practice in any field of human existence develops by itself if one comprehends the contradictions in every new process; it consists in siding with those forces which act in the direction of progressive development. To be radical, according to Marx, means "going to the root of things." If one goes to the root of things, if one understands their contradictory character, the means of mastering the reaction become plain.

Ch. 1 : Ideology As Material Power, Section 1 : The Divergence Of Ideology And Economic Situation - The Mass Psychology of Fascism (1933)