 Although these are categories of the understanding, they nonetheless retain a certain sort of ontological import, as it is a priori that they apply universally to all objects of possible cognition (A79/B105). In this way, by delineating the concepts that are a priori necessary for the cognition of objects, we can acquire knowledge of categories governing any possible object of cognition, and so acquire a sort of descriptive set of ontological categories, though these must be understood explicitly as categories of objects of possible cognition, not of the thing in itself. Thus Kant was able to treat his system of concepts as a system of categories in something like the Aristotelian sense, “for our primary purpose is the same as his [Aristotle’s], although widely diverging from it in manner of execution” (A80/B105). Nonetheless, it is clear that for Kant the categories find their original source in principles of human understanding, not in intrinsic divisions in mind-independent reality, and are discoverable by paying attention to possible forms of human judgment, not by study of the world itself, nor by study of our contingent manners of speaking.