: Kant’s 1763 essay, Attempt to Introduce the Concept of Negative Magnitudes into Philosophy, is one of the least discussed of all his pre-critical writings. When it is referred to, it is usually just to note a few passages that anticipate Kant’s later, Critical philosophy. I argue that instead of understanding these early anticipations of the Critical philosophy as separable from Kant’s discussion of negative magnitudes, we should take their origin in Kant’s investigation of negative magnitudes to be of central (...) importance, since it can help us to understand aspects of Kant’s Critical view of cognition where negative magnitudes still play a role. I argue that negative magnitudes suggest to Kant a kind of cognitive activity that is neither the spontaneity of discursive thought not the receptivity of the senses. Rather it is an “effort” of the mind, of which we are conscious through a feeling. I show that Kant’s early views about negative magnitudes are retained in his Critical philosophy. (shrink)