Discourse and knowledge are two closely related fundamental concepts in humanities and social sciences, but they have often been treated separately. Based on the multidisciplinary perspectives of Epistemology, Cognitive Psychology, Social Psychology, Cultural Anthropology and Linguistics, this paper addresses van Dijk's integrated study of discourse with knowledge, with the focus on his construction of “discourse-cognition-society” triangular theoretical framework and the proposal of a new field “Discourse Epistemics”. A brief critique is then given, followed by suggestions on future studies.