The core project of this dissertation is twofold. First, it provides a reconstruction of Kant's theory of how sensation contributes to the cognition of physical objects in the spatiotemporal world. It is first shown how sensation acquires a representational function through its relation to the mental states that Kant labels "intuitions." In intuitions, a posteriori sensations are combined with the a priori representation of space to produce nonconceptual representations of sensory qualities arrayed in space. These intuitions yield our most basic representations of objects in the world. Then it is shown how the data given in sensory intuitions allows for the application of some of our most basic conceptual representations of these objects, most importantly the concepts of "reality" and "actuality." We can represent something as real because sensations allow us to determine the "intensity" of an object's physical density and sensible qualities. We can represent an object as actual when the representation of that object coheres with the rest of our sensory representations of the natural world. Second, it is argued that a careful analysis of the "intentionality" of our sensory representations reveals the ontological status of the objects of cognition to be quite minimal. The empirical objects we represent in experience, Kant thinks, have no existence beyond their being what is articulated by the representational contents of intentionally--directed mental states. This, it is argued, is the proper understanding of Kantian idealism, and it is shown that this interpretation is maximally consistent with Kant's relevant writings on the issue. These two projects are by no means distinct, for Kant argues that intentional relations to empirical objects are possible only because of the a posteriori matter given in sensation. The most novel contribution of the project lies in showing how Kant's theory of the ontological status of appearances can be understood as a consequence of his theory of how sensations make possible our intentionally- directed empirical representations