First order logic, set theory and God

[GrandizerII]

The point of p2 was to arbitrarily, and incorrectly (again, as rahn commented in that same post) exclude all other causes that could very well be one of the essential whatsits from consideration.

I think Rahn misunderstood P2 and that the OP isn't saying that because gravity (A) causes some planet (B) that A directly causes all the later stuff that happens to it and/or becomes a part of it. I think what the argument is is that A causes B and all the stuff that collectively is B at the time A caused B.

That said, I still don't see the exact point behind P2. Can not the "first cause" cause the set that comprises it? And since it is "self-caused", then P2 could be true but it wouldn't rule out such a "first cause".

Note I haven't actually read the second half of his OP (so maybe I should get to that soon).