Jürgen Habermas asserts, in the Preface to Knowledge and Human Interests, that a radical critique of knowledge, that is a metacritique of epistemology, is only possible as a social theory. In this essay, Garbin Kortian discusses the implications and philosophical import of this thesis, which is central to Habermas's work, through a critical account of the German philosophical tradition in which it stands. He relates the 'metacritical dimension' of Haberbas's thought to Hegel's critique of Kant, Marx's critique of Hegel, and the Frankfurt school's critique of positivism. Kortian presents his perspective on the philosophical problems Habermas's argument faces: the primacy of practice, this philosophy of understanding and the hermeneutic concept of understanding. This book, which was originally published in French, will interest students of philosophy and of the social and political sciences.