Epistemology should be the axe that breaks the ice of a traditionalism that covers and obstructs scientific enlightenment. This book explores the arguments between critical theory and epistemology in the twentieth and twenty-first centuries. Focusing on the first and second generations of critical theorists and Luhmann's systems theory, it examines how each approaches epistemology. The book offers a critique of the Kantian base of critical theory's epistemology in conjunction with the latter's endeavour to define political potential through the social function of science. The concept of dialectics is explored as the negation of the irrational and, furthermore, as the open field of epistemological conflict between rationality and irrationality. The book traces the course of arguments that begin with Dilthey's philosophy of a rigorous science, develop with Husserl's phenomenology, Simmel's and Weber's interest in the scientific element within the social concerns of scientific advance. In structuralism, the fear of dialogue prevails. The book discusses the epistemological thought of Pierre Bourdieu and Gilles Deleuze in terms of their persistence in constructing an epistemological understanding of social practice free from the burdens of dialectics, reason and rationality. It also enquires into issues of normativity and modernity within a comparative perspective on modernism, postmodernism and critical theory. Whether in relation to communication deriving from the threefold schema of utterance- information- understanding or in relation to self- reflexivity, systems theory fails to define the bearer or the actor of the previous structural processes. Critical realism attempted to ground dialectics in realism.