On possible worlds and God, a proscription

Although many philosophers take the notion of metaphysical possibility to be primitive, it is often glossed as "how things might have been" or "how God might have made things" (see the introduction to Tamar Gendler and John Hawthorne, eds., Conceivability and Possibility, pp. 4-5). In terms of possible worlds, David Chalmers (op. cit.) writes of "an intuitive conception of a metaphysically possible world as a world that God might have created" (146). Of these two glosses on the notion of metaphysical possibility, I believe that the first is preferable and the second ought to be discarded.

Consider the following version of the argument from evil.

Suppose God exists and is omniscient, omnipotent, and perfectly good. Being omniscient, God knows which of all the possible worlds would be the best. Being perfectly good, he would create that world rather than any other if he could. He can, because he is omnipotent. Therefore, since this is the world God did create, this world must be the best of all possible worlds, including those possible worlds that contain less suffering. Since it's easy to imagine a possible world that is better in virtue of containing less suffering, this isn't the best of all possible worlds. Therefore, either God does not exist, or God is not omniscient, omnipotent, and perfectly good.

There is a standard response to this line of argument that invokes the notion of free will. It goes something like this.

If free choices are valuable, then even a perfectly good God might prefer a world in which some of his creations have the capacity for free choice to any that lacks this feature. But even an omnipotent God can’t create a world in which there are free beings who make free choices that are always for the best. If he used his power to determine that all the actions of his creations be always for the best, then none of those actions would be free. The capacity for free choice includes the capacity to act badly as well as the capacity to act well.

But then how the world is won’t be entirely up to God. We, as the free agents God created, are partly responsible for how the world is. If we act well, the world will be better than it might have been, and if we act badly, the world will be worse than it might have been. Since, in fact, we sometimes act badly, there are ways the world could have been better than it is. But this is our fault and not God’s. Therefore, God might be perfectly good, omniscient, and omnipotent, even though the world is not the best of all possible worlds.

This response entails that there are ways the world might have been which are not ways God might have made the world. The two glosses are not coextensive. For the descriptions of the possible worlds in question include the claim that some of the features of those worlds are not up to God. Even God cannot make it the case that (P and God does not make it the case that P). But there are surely ways the world might have been in which (P and God does not make it the case that P).

If we assume that ways things might have been are just ways that God might have made things, then these possible worlds are obscured. It may be that the worlds in question are not metaphysically possible, but the believer who makes this response to the argument from evil will surely cry "foul!" if we claim that they lack the proper "intuitive conception of a possible world," especially when there is a perfectly good alternative gloss that is not obviously coextensive.

We should not describe metaphysical possibilities as ways God might have made things. Leave God out of it.