László F. Földényi at The Paris Review:
As I fall asleep, I leave my body and my soul behind, all the while palpably returning back to my body and my soul. But what is actually going on here? It is not my body that has changed, or my soul, but rather my relation to both. By day, when I’m awake, I usually observe my body from without, and although I am only capable of imagining myself as a physical body, I don’t identify myself with it. In a similar way, I don’t fully identify with my soul either. If I’m awake, for the most part I think of it, as it were, as someone (or something), which cannot exist without me, and yet is not completely identical to me. I would almost speak of it in the third-person singular. This is Descartes’s final inheritance; not even I can avoid his influence. In the moment when I began to speak about the body or about the soul, I unwittingly behave as if it were possible to distinguish between them. And in doing so I imperceptibly differentiate myself from them. I create a differentiation between the soul and the body.
more here.