In this essay, we read Derrida's Theor y and Practice seminar against the backdrop of the theme of the "death of philosophy," prominent in 1960s French philosophy. This theme takes two forms-one Nietzschean-Heideggerian and the other Hegelian-Marxian. We summarize both before turning to Derrida's treatment of Althusser's views on the Hegelian-Marxian form of this death. Althusser posits a distinction between theory in the general sense and Theory as a designation for Marxist dialectical materialism. Derrida gives two specific criticisms of Althusser that we discuss: (1) Althusser commits himself to a tautology, by arguing that Theory only makes explicit what is implicit already in Marxist practice; (2) Althusser ultimately establishes the priority of practice over theory. We refute both of these charges before concluding that, prior to the distinction between theory and practice, is the world itself ; and presenting itself to us as unthinkable, the world places the demands upon us that it be engaged with, in theory and in practice.