In this paper I ask to what extent Kant anticipates Deleuze’s transcendental empiricism, both in his identification of problems within transcendental idealism, and in his speculative solution to them with the concept of ether. In the first half I set out three motivations for adopting transcendental empiricism as Deleuze formulates it. I then look at Kant’s identification of three problems concerning sensation that relate to these motivations. In the second half I suggest that Kant’s own solution to his three problems of sensation, the concept of ether, is similar in some respects to Deleuze’s virtual. I will argue that in his late work, Kant moves towards transcendental empiricism, but that his retention of the transcendent prevents his fully embracing it.