Abstract: In the paper, we explore the relations between knowledge and thinking in the context of postmodern criticism, hoping that the discussion can contribute to the reform in foreign language teaching. The role of knowledge has long been overlooked in foreign language teaching, and knowledge has been mistaken for information. As a result, imparting knowledge is reduced to sharing fragments of information. We argue that knowledge provides cognitive frameworks and basic procedures for thinking, without which thinking suffers in depth and translingual intertextual ties cannot be established. It is because foreign language teaching does not pay sufficient attention to the systematicity of knowledge in its practice that students have problems in critical thinking. We believe postmodern criticism of knowledge can help us understand better the roles of knowledge in thinking, and on the other hand, the paradox in postmodernism can shed light on how to handle the relations in teaching.