Theistic multiverse, omniscience and contingency

A number of people have been puzzled by the somewhat obscure arguments in my “Divine Creative Freedom” against a theistic modal realism on which (a) God creates infinitely many worlds and (b) a proposition is possible if and only if it is true at one of them.

So, here’s a simplified version of the main line of thought. Start with this:

1. For all propositions p, necessarily: God believes p if and only if p is true.

2. There is a proposition p such that it is contingent that p is true.

3. So, there is a proposition p such that it is contingent that God believes p. (1 and 2)

4. Contingent propositions are true at some but not all worlds that God creates. (Theistic modal realism)

5. So, there is a proposition p such that whether God believes p varies between the worlds that God creates. (3 and 4)

Now, a human being’s beliefs might vary between locations. Perhaps I am standing on the Texas-Oklahoma border, with my left brain hemisphere in Texas and my right one in Oklahoma, and with my left hemisphere I believe that I am in Texas while with my right one I don’t. Then in Texas I believe I am in Texas while in Oklahoma I don’t believe that. But God’s mind is not split spatially in the same way. God’s beliefs cannot vary from one place to another, and by the same token cannot vary between the worlds that God creates.

An objection I often hear is something like this: a God who creates a multiverse can believe that in world 1, p is true while in world 2, p is false. That's certainly correct. But those are necessary propositions that God believes, then--it is necessary that in world 1, p is true and that in world 2, p is false, say. And God has to believe all truths, not just the necessary ones. Hence, at world 1, he has to believe p, and at world 2, he has to believe not p.