In order to fully perceive the actions of others we create simulations in our minds of the same action as it would be if we ourselves were doing it. This enables us to feel the action internally and thus to prepare the nervous potentials required for repeating or mimicking the same action. This is a fairly well-accepted picture of an efficient computational matrix for a trait with obvious evolutionary advantages when present in a certain degree. A simpler way of describing it is to say that we perceive actions via our kinaesthetic body. It then becomes clear that we perceive more than the actions of others in this way and that our entire orientation in the spatio-temporal world of physical objects is mediated by such a body in complex ways that are more subtle than mere mirroring. The architectural and decorative arts doubtless provide many examples of this. If this way of thinking of a kinaesthetic body is accepted then why not extend it to other sorts of internal bodies such as a thought body, a feeling body and a will body, as well as an energetic body. There is thus a subjective sense of high neural engagement in that we are peripherally aware of how much work our brains are doing to construe complete immersive realities, the quantum of work seeming to bear a geometric relationship to the number of polyphonic perceptual tracks. Here work may be exhausting but it is also stimulating; we crave and greatly enjoy high engagement and only belatedly notice that it has tired us out, but with a good kind of tiredness. Again, through the will-body we are opened to a world of competing wills, it is the world of the warrior and the hunter in a very general sense. It also mediates the kind of perception with which we enjoy sports and games and with which we throw ourselves into political and ideological struggles. To be immersed in the world is to have a polyphonic or multi-layered body fully engaged on all levels, so that the body and the world lack any clear demarcation. The two are phenomenologically as different as can be since the body says I in the teeth of the world, but the boundary between them is mobile.