This paper compares Kant’s and Leibniz’s views on the relation between knowing subjects and known objects. Kant discusses Leibniz’s philosophy in the ‘Amphiboly’ section of the first Critique. According to Kant, Leibniz’s main error is mistaking objects in space and time for mind-independent things in themselves, that is, for monads. The paper argues that, pace Kant, Leibniz regards objects in space and time as mind-dependent. A deeper divergence between the two philosophers concerns knowing subjects. For Leibniz, they are substances. For (...) Kant, we cannot know whether they are substances. Kant conceives of knowing subjects as complex systems of cognitive capacities. (shrink)