In this paper I address Jacques Derrida's consistent phenomenological critique of his colleague Louis Althusser. Over the course of many decades, Derrida explicitly draws attention to what he takes to be Althusser's problematic pre-critical scientism, which is the direct result of the latter's failure to engage with Husserl and Heidegger. However, as I attempt to show, Althusser sought to reveal deeper problems associated with transcendental-critical questions in post-Kantian philosophy. For Althusser, questions concerning the ‘conditions of possibility’ of knowledge and experience (...) reproduce the idealist problematic that he calls ‘empiricism’. Charting a different trajectory within contemporary French philosophy, Althusser combines insights from Spinoza, Marx, and other figures often unmentioned by Derrida to produce a novel, non-transcendental philosophical approach to key problems that arise in epistemology and the philosophy of science. (shrink)