In his process, he uses "meta-metaphors" if you please.
Each the layer of an onion. But he turns them over with such care and close scrutiny as to call to mind string theory, which reveals dimensions heretofore not seen or imagined, because of their proximity. Each become a landscape unto itself, and each landscape populated with new metaphors that must be mined if the impulse to do philosophy is to be abandoned.
As we follow in his footsteps, we always and repeatedly surmise that there is a solid core at the center -- in other words, that the onion is an avocado, not an onion, in this respect. And therefore he must show us repeatedly, like dogs being trained to sit on command, that at the center there is nothing, or perhaps nothing but the sound of our own breathing, and only, to be sure, for as long as we have breath to draw.