 The theory of the infinitesimals of perception is both complex and exceedingly opaque, and perhaps for this reason it largely disappears from Maimon’s later work (for more on infinitesimals, see Duffy 2014). But despite its gradual diminution in Maimon’s thought, the spirit it reflects continues to be expressed in Maimon’s steadfast commitment to his ‘skeptical rationalism’. Both his objections to Kant’s account of cognition as well as his own positive project turn on a rejection of what might be called ‘brute givens.’ For Maimon, givenness stands in opposition to cognition, for he holds that no explanation can be provided for how merely given content can be taken up in thought — how, that is, the active faculties of thought can legitimately apply to a passively received given. By attempting to explain givenness within a larger framework of an active consciousness, Maimon presents a position that avoids — at least in principle — the problems that Maimon sees with Kant’s cognitive dualism.