Modality and Theodicy

Here’s a juicy post from Brian Weatherson (via this Weatherson post at Crooked Timber (which was also cross-posted at his personal blog – got that?)).

The gist:

Let’s assume the following metaphysical claims are all true.

• There is a class of abstract possible worlds W. (I’m not going to say what abstract and concrete amount to in any of this – on this distinction see Gideon Rosen’s SEP entry.) In other words, weak modal realism is true.
  
• God cannot change any of those worlds without destroying it – what happens in a world is essential to its nature.
  
• What God can do is make any of them that He chooses concrete. Abstract possible worlds have no moral value, but concrete worlds do have value, or disvalue if they are bad, so this choice is morally loaded.
  
• God’s creation is timeless, so He can’t create one and then tinker with it. For each world He faces a take-it-or-leave-it choice.

Just to be clear, I’m not saying these are true. I’m just saying they are a plausible set of views about the nature of modality and the nature of God’s powers. Note that the only ‘restriction’ on God’s powers here are of the form “God can’t do this metaphysically impossible thing”, i.e. make something lack one of its essential properties, so in that respect this isn’t meant to be a revisionary theology. (It’s revisionary metaphysics, not revisionary theology.)

If all this is true, what should God do? Well, I think He should create all and only the worlds such that it is better that they exist than that they not exist. And that will include worlds, like this one, that are not perfect but that contain more goodness than suffering. So the existence of this world as concrete entity is compatible with God’s existence, and indeed His omnipotence and benevolence.

Readers may recognize this as a form of Leibniz’s theodicy, with one important qualification: Weatherson thinks that God is off the hook so long as the world(s) he actualizes contain(s) more good than evil, as opposed to being the best possible world as Leibniz thought.