The Eleatic argument that motion is impossible because infinite series cannot converge to finite sums was simply a mathematical misunderstanding. This was cleared up centuries ago-- Arab mathematicians understood this quite well. Spengler's claim that this had never been answered simply shows that Spengler's dilletantish knowledge did not include any basic understanding of mathematics. Like Kant, Hegel, and Schopenhauer, he was a master in using lots of bafflegab to express very little, an extraordinarily tedious author to read. He had some useful things to say, or he wouldn't still be remembered, but I don't understand how you can fail to see his thorough wrongheadedness even in the subject of historical patterns where he did have some actual expertise; and to cite him as an "authority" on subjects he knew next to nothing about is an absurdity. Here, at least, you are quoting somebody who has some grasp on the topic. YES, the concept of a "BEING IN ITSELF" (noumenon as Kant tagged it) is dead. All beings are inextricably related to all others, and have reality only as part of that universal whole. Spengler doesn't understand how any physics can function without beings that can be plucked out, away from all other beings, and examined as isolated units; but in fact, physics is doing quite well without that old framework. What you want is to preserve ONE "being in itself", pretending that God can exist as an isolated reality with or without all the other beings. This is tacking on a fifth wheel-- to a vehicle which has already left the ground and has no use for wheels at all anymore.