Several authors have detected profound analogies between Kant and Wittgenstein. Their claims have been contradicted by scholars, such being the agreed penalty for attributions to authorities. Many of the alleged similarities have either been left unsubstantiated at a detailed exegetical level, or have been confined to highly general points. At the same time, the ‘scholarly’ backlash has tended to ignore the importance of some of these general points, or has focused on very specific issues or purely terminological matters. To advance the debate, I distinguish four different topics: questions of actual influence; parallels at the methodological level; substantial similarities in philosophical logic; substantial similarities in the philosophy of mind. The article concentrates on the second and third topic. Section I argues that the critical conception of philosophy shared by Kant and Wittgenstein is itself due to the fact that they explain the a priori status of necessary propositions by reference to the way we experience or represent reality. Section II shows how the Tractatiis linguistically transforms this ‘reflective turn’, replacing Kant's preconditions of experience by preconditions of symbolic representation. Section III suggests that this explanation of the a priori involves the idea of an isomorphism between thought and reality, and that both Kant's transcendental idealism and Wittgenstein's early metaphysics of symbolism distort this isomorphism. Wittgenstein later rejected this metaphysics of symbolism, on the grounds that language is autonomous, and section IV detects parallels between that idea and Kant's ‘diallelus’ argument against the correspondence theory of truth. Finally, I claim that while Wittgenstein is right to insist that all a priori propositions are conceptual, Kant, in calling them synthetic a priori, is right to deny that they simply unpack the concepts involved in the propositions themselves.