Here is a plausible principle:
- If p is partly grounded in q, then p does not explain q.
But the best account of divine simplicity commits one to:
- That God willed horses to exist is partly grounded in there existing horses.
(For, that God willed horses is a contingent fact. By divine simplicity any contingent fact about God must be partly grounded in realities outside of God. And the only plausible candidate for the reality outside of God here is the fact that there exist horses.)
Therefore:
- That God willed horses to exist does not explain why there are horses.
This seems very counterintuitive, sufficiently counterintuitive to provide an argument against divine simplicity, or against (1).
But I think one should just accept (3). For even apart from considerations of divine simplicity, it is plausible that God’s will is so strongly efficacious that his willing something just is his making it be so:
- God’s willing horses to exist just is God’s causing horses to exist.
But in general, even apart from the divine case, x causing y is partly grounded in both x and y, and hence is partly grounded in y. Thus:
- God’s causing horses to exist is partly grounded in horses existing.
It seems to follow (there are tough issues involving the hyperintensionality of grounding) that:
- God’s willing horses to exist is partly grounded in horses existing.
In fact, once we understand that God’s (consequently) willing and God’s causing are the same thing, then the paradox in (3) is just very much like:
- My causing a boomerang to exist does not explain why the boomerang exists.
But we have good reason to accept (7). For when I made a boomerang some years back, that I caused a boomerang to exist was partly grounding in a boomerang existing. (A boomerang might not have eventuated from what I was doing. Instead, I might have been left with a broken piece of wood.) But then by (1), I have to accept (7).
What is unfortunate for me is that for a long time, in print and in speech, I’ve been happy to accept claims like:
My causing a boomerang to exist explains why the boomerang exists.
God’s willing horses to exist explains why horses exist.
I still find it difficult to deny (8) and (9).
Maybe I should deny (1) instead. But I don’t want to. I am strongly committed to there not being any circles of explanation, even ones involving different kinds of explanation (say, causal and grounding).
Maybe I can save the intuitions behind (8) by saying:
- My actuating my causal power of boomerang production explains why the boomerang exists.
(Note that my actuating that causal power does not entail a boomerang exists. A causal power can be actuated unsuccessfully.)
And maybe I can save the intuitions behind (9) with:
- God’s desiring that horses exist explains why horses exist.
(God’s desiring something doesn’t entail that thing’s existing, since God desires every good, and some goods are incompatible with one another.)