This dissertation concerns the nature of proprioceptive awareness—the distinctive awareness “from the inside” that we each have of the position of our limbs and other body parts. As the prevailing view would have it, this awareness is perceptual. It, like sight or touch, is a way that each of us has of coming to grips with an independent reality. That what we come to grips with in it happen to be parts of us makes no difference to the nature of this awareness. I argue, on the contrary, that this awareness is not perceptual—that our bodies and the proprioceptive awareness we have of them are constitutively tied. This awareness is not one that we just happen to have of ourselves but one that we have in being the kind of subjects we are, in being bodily subjects. I develop this epistemological point about our bodily self-knowledge through a metaphysical account of the nature of the body. For many, having a body comes to little more than our being physical, than our being flesh and bone. But, as I argue, having a body is indissociable from some of the capacities we have as subjects. It is not just a matter of our taking up space but of our being present in the space that we take up, of our subjectivity’s extending to this space. Our proprioceptive awareness, I show, is central to this and, in this way, constitutive of our bodies.