Perhaps you are asleep and dreaming now, but if we bracket the question of what physical objects are made of (3-dimensional particles, or our own thoughts in a dream, or 10-dimensional strings, or whatever), then physical objects are definitely possible. Your body, for instance, is actual, so it is possible. And mental states are also possible, of course. And insofar as we do not know for sure that a God is not a possibility, a God is an epistemic possibility. And because it is, in that sense, possible that God created you, it is similarly possible that as well as creating you, a God created an exact copy of you in an identical universe, because if a God could create this universe then a God would be able to create an identical one (even if that God would not want to create an identical one). Now, it is similarly possible (if implausible) that a God who had made you and an identical copy of you might swap you with that other person, and swap you back, and do that over and over. And the same goes for everything else in this universe. Such swaps could conceivably be happening all the time, for all that we could tell just by looking around us, however closely we looked.
Does that make a God seem unrealistic? But this is not a problem with the possibility of there being a God. Do we know for sure that fundamental particles (or whatever substances are physically fundamental) could not be replaced by identical particles (or substances)? We naturally assume that such replacements do not occur, but such replacements would make no difference empirically, so we cannot rule them out empirically. And prima facie, we cannot rule them out on purely logical grounds. And while they may well seem unlikely, that is only because we are implicitly assuming that they never happen. We have no empirical or logical grounds for believing them to be unlikely. For all we know, they could be happening all the time. We simply assume that they do not happen at all.You and that hypothetical identical copy of you would not be the same person, even though there would be nothing to tell you apart. That should be obvious because the copy of you would now be in another universe. And the same goes for me, of course. You can refer to me by name (my name is in the sidebar), and that reference should be simple and direct: it should be me that you refer to, not someone else. And of course, it is me that you would be referring to. Or so we assume. The way reference works amounts to an assumption that such swaps do not occur. It is almost magical the way your referring to me means that a host of things that could, for all we know, be happening are not in fact happening.
The thing is, the solution to that logical problem may well be the probability of there being a God.Logic tells us that things are such that there is Cantor's paradox, and from that paradox we can get, in a purely logical way, to the probable existence of a God. Would such a God make such swaps as those considered above? There may well be good reasons why a God would not do that. So, logic may well show that such swaps are unlikely. It is something to think about...
