Tuesday, June 26, 2012

An ontological argument based on powerful-making properties

  1. (Premise) The property, WA, of being such that for every world w it is possible for one to weakly actualize w is a powerful-making property.
  2. (Premise) No powerful-making property entails the property, PL, of being powerless.
  3. If WA is not possibly exemplified, then it entails all properties. (Fact about property entailment)
  4. So, WA is possibly exemplified. (1-3)
  5. (Premise) Necessarily, if x weakly actualizes w then x exists and w has been actualized.
It follows by S5 that there actually exists a being that has WA and that has weakly actualized our world.

Weak actualization is Plantinga's concept. We might inductively say that whatever x directly creates is weakly actualized by x, and whatever comes from something weakly actualized by x is weakly actualized by x.

4 comments:

Heath White said...

1. I'm not following the proof from S5. I get that it is possible that x exists and has created the actual world. But I'm rusty on my modal logic.

2. Wouldn't Plantinga say that God cannot weakly actualize any possible world w, since the CCF's constrain the feasible worlds? And in that case, does your proof disprove transworld depravity? Or is TWD just the rejection of a premise?

vexingquestions said...

Dear Dr. Pruss,

Would it matter to the argument whether PL is metaphysically possible? Is PL metaphysically possible? I could imagine some entity that has powerlessness with respect to a particular power, but I have a hard time accepting that an entity might be powerless full-stop.

Thanks,

Daniel

James said...

I think (2) is phrased deceptively.

The intuition seems to be, any entity that possesses some powerful-making property, PM, cannot also possess PL.

But suppose that there are no entities possessing powerful-making properties. Then it is true that "Every entity possessing powerful-making properties possesses PL." But this does not violate the intuition; that would require the existence of an entity that possessed both PM and PL.

Alexander R Pruss said...

Heath:

1. It either is or is not true that x has created the actual world. If it's not true, then it's a part of the actual world that x has not created the actual world. But if it's a part of the actual world that x has not created the actual world, then x can't have created the actual world, since x can't have created a world not created by him. Roughly speaking.

2. I am not talking of what God can or cannot weakly actualize, but of what is or is not *possible* for God to actualize. On Plantinga's view, it's possible that God actualizes w, where w is in fact infeasible-- but only because w could have been feasible.

Daniel:

Yeah, maybe weaken PL just to be the inability to cause matter to be displaced.

James:

That would be an intuition of incompatibility. The intuition I am working with is that if a property entails powerlessness, it's not a powerful-making property.