  Habermas defended this philosophical anthropology most fully in his Knowledge and Human Interests (1971b; German ed., 1968b), the work that represents his first attempt to provide a systematic framework for an interdisciplinary critical social theory. As Habermas conceived his task, he had to establish critical social theory as a respectable, distinct form of knowledge, in large measure through a methodological critique of the then-dominant positivist philosophy of science and historicist hermeneutics. He thus develops a theory of “knowledge-constitutive interests” that are tied both to “the natural history of the human species” and to “the imperatives of the socio-cultural form of life,” but are not reducible to them (ibid., 168).