Here is a simple proposal:
A being x is omnipotent provided that in every possible world, x’s free choices are collectively the ultimate explainers of the rest of contingent reality.
In particular, only a necessary being can be omnipotent. Whether omnipotence is compatible with created free will depends on how exactly we spell out “ultimate explainers”. We might think that if y in situation S freely chooses to A, and God creates y in S, and y freely chooses to A, then God’s creation is an ultimate explainer (it may or may not be the case that an ultimate explainer of a proposition is an explainer of the proposition).
This definition is incompatible with Molinisms on which God is not an ultimate explainer of conditionals of free will.
If the above account is right, we have a sound ontological argument along the lines of the standard S5 ontological argument:
- Possibly, there is an omnipotent being.
- Therefore, there is an omnipotent being.
I’ve been teaching an introductory philosophy course this semester with a new text for my God unit, Thinking About God by Greg Ganssle. It’s designed to be usable for high school or introductory college/university courses, and it’s just about the lowest level of detail that I would want to use for this course. I’m supplementing it some with other readings also, but it’s nice to spend a lot of time just in one book after using lots of scattered readings in past versions of the course.
One thing that I found really interesting was in the section on the logical problem of evil. The logical problem of evil presents three traditional attributes of God (omnipotence, omniscience, and perfect goodness) and then seeks to derive a contradiction if you admit to the existence of evil (which pretty much all traditional theists will do, and thus it’s a problem even if the person presenting the problem doesn’t happen to believe in evil, because the theist does, and it’s supposed to be a contradiction for theism). Now it so happens that hardly any philosopher today accepts the logical problem of evil as a good argument, for several reasons, but in the process of explaining why Ganssle hits on an interesting issue that I hadn’t thought of before. One way some people have resisted theists’ attempts to respond to the problem of evil might actually help the theist in surprising ways.