Do God's beliefs cause their objects?

Consider this Thomistic-style doctrine:

1. God’s believing that a contingent entity x exists is the cause of x’s existing.

Let B be God’s believing that I exist. Then, either

2. B exists in all possible worlds

or

3. B exists in all and only the worlds where I exist.

(Formally, there are other options, but they have no plausibility. For instance, it would be crazy to think B exists in some but not all the worlds where I exist, or in some but not all the worlds where I don’t exist.)

Let’s consider (3) first. This, after all, seems the more obvious option. God’s beliefs are necessarily correct, so in worlds where I don’t exist, God doesn’t believe that I exist, and hence B doesn’t exist. Then, B is a contingent being that causes my existing. Now apply the Thomistic principle to this contingent being B. It exists, so God believing that B exists is the cause of B’s existing. Let B₂ be God’s believing that B exists. Since B₂ causes B, B₂ must be distinct from B, as causation cannot be circular. Furthermore, if (3) is the right option in respect of B and me, then an analogue for B₂ and B should hold: B₂ will exist in all and only the worlds where B exists. The argument repeats to generate an infinite regress of divine believings: B_n is God’s believing that B_n − 1 exists and B_n causes B_n − 1. This regress appears vicious.

So, initial appearances aside, (3) is not the way to go.

Let’s consider (2) next. Then B exists in some possible world w₁ where I don’t exist. Now, at w₁, God doesn’t believe that I exist, since necessarily God’s beliefs are correct. This seems to be in contradiction to the claim that B exists at w₁. But it is only in contradiction if it is true at w₁ that B is God’s believing that I exist. But perhaps it’s not! Perhaps (a) the believing B exists at the actual world and at w₁ but with different content, or (b) B exists at w₁ but isn’t a believing at w₁.

Let’s think some more about (2). Let w₂ be a world where only God exists (I am assuming divine simplicity; without divine simplicity, it might be that in any world where God exists, something else exists—viz., a proper part of God). Then by (2), B exists at w₂. But only God exists at w₂. So, God is identical to B at w₂. But identity is necessary. Thus, God is actually identical to B. Moreover, what goes for B surely goes for all of God’s believings. Thus, all of God’s believings are identical with God.

It is no longer very mysterious that God’s believing that I exist is the cause of my existence. For God’s believing that I exist is identical with God, and of course God is the cause of my existence.

The difficulty, however, is with the radical content variation. The numerically same mental act B is actually a believing that I exist, while at w₂ it is a believing that I don’t exist. Furthermore, if truthmaking involves entailment, we can no longer say that B truthmakes that God believes that I exist. For B can exist without God’s believing that I exist.

All this pushes back against (1). But now recall that I only called (1) a “Thomistic-style” doctrine, not a doctrine of St. Thomas. The main apparent source for the doctrine is Summa Theologica I.14.8. But notice some differences between what Aquinas says and (1).

The first is insignificant with respect to my arguments: Thomas talks of knowledge rather than belief. But (1) with knowing in place of believing is just as problematic. Obviously, it can’t be a necessary truth that God knows that I exist, since it’s not a necessary truth that I exist.

The second difference is this. In the Summa, Aquinas doesn’t seem to actually say that God’s knowledge that x exists is the cause of x’s existence. He just says that God’s knowledge is the cause of x’s existence. Perhaps, then, it is God’s knowledge in general, especially including knowledge such necessary truths as that x would have such-and-such nature, that is the cause of x’s existence. If so, then God’s knowledge would be a non-determining cause of things—for it could cause x but does not have it (and, indeed, in those worlds where x does not exist, it does not cause x). This fits well with what Aquinas says in Article 13, Reply 1: “So likewise things known by God are contingent on account of their proximate causes, while the knowledge of God, which is the first cause, is necessary.”

Maybe. I don’t know.