Tuesday, August 16, 2011

Theists can't be anti-libertarians

Strong anti-libertarians believe that choices need to be determined by our motives in order to be free.  Weak anti-libertarians believe that choices need to be probabilified, with a probability greater than 1/2, by motives in order to be free.

Strictly speaking, one could be a libertarian and a weak anti-libertarian.  But it would be odd.  As a weak anti-libertarian, one would say something like this:  When I am choosing between two equiprobable options, I am not free.  It's just chance how I choose.  When I am choosing between an option A whose probability is greater than 1/2 and another option B, I may be free if I choose A, but I won't be free if I choose B.  And that would be a weird thing for a libertarian to say.

Theists should be neither weak nor strong anti-libertarians.  Consider these two plausible premises:
  1. Necessarily, whatever God chooses, he chooses freely.
  2. God made at least one choice that it was possible for him to have made otherwise.
I actually think premise 1 is true for any agent: I think non-free choices are impossible.  But that's very controversial, and the special case of God is much more clear.  If non-free choices are possible, surely God isn't going to be making any such--that would surely be contrary to an important aspect of omnipotence.

Premise 2 is I think a part of standard religious views.  For instance, Catholics are committed (by the First Vatican Council) to the claim that God isn't necessitated to create.  Christians more generally tend to think that God has chosen to redeem us, but did not have to.  It would, I think, be difficult to reconcile omnipotence with a denial of 2--we can perhaps allow that doing wrong or doing the impossible are things an omnipotent being can't do, but surely some alternate options are needed for omnipotence.  Moreover, merely conditional "had he willed otherwise, he would have done otherwise" options won't be enough to do justice to omnipotence.

We can also argue for premise 2 as follows.  Intuitively, there is a possible world w* which has no contingent beings in common with our world.  God exists necessarily.  Hence, God exists at w*.  At w*, God must have decided something differently from what he decided in our world.  (Some differences between worlds can be due to inter-creaturely causal processes having gone differently.  But in this case because w* has no contingent beings in common in our world, the differences can't be like that.)

If one accepts 2, one has to deny strong anti-libertarianism.  And if one accepts both 2 and 1, one has to deny weak anti-libertarianism.  For suppose God is choosing between alternatives A and B and can choose either one.  Then it cannot be that both the alternatives have probability greater than 1/2.  Hence at least one of the alternatives fails to have probability greater than 1/2.  Let's say that's B.  Now consider a world where God chooses B.  That's a world where God chose something that did not have probability greater than 1/2.  But by 1, the choice was still free, contrary to weak anti-libertarianism.

It doesn't follow that theists have to be libertarians.  But they have to think that freedom is compatible with lack of determinism.

[Edited to reflect my view that all choices are free. -ARP]

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