Freedom and the problem of evil › Possibility and actualization

A possible world is a complete way things could have been. It is not necessarily a distant physical universe. Talking about a world where a person freely keeps a promise describes a possible history, including the person's action. It does not yet tell us who can bring that history about.

Plantinga challenges the assumption that omnipotence entails being able to actualize every possible world. Where a history includes undetermined choices by others, bringing about the surrounding circumstances need not determine the complete history. God's creating an agent and placing her in a situation would not, on this account, amount to causally producing her free decision.

A useful distinction concerns what would happen if particular circumstances were actual. A counterfactual of freedom says, for example, that if a person faced a certain temptation in specified circumstances, she would freely resist. Such a conditional is stronger than saying she could resist. The first concerns what she would do; the second concerns an ability or possibility.

Suppose, in a hypothetical case, that she would freely break the promise in the circumstances God brings about. The complete world in which those circumstances obtain and she freely keeps it might still be logically possible. But those circumstances would not be a route by which God could actualize that world, given what she would freely do. Making her decision causally inevitable would change the kind of action being described.

This distinction does not automatically vindicate Plantinga. A critic can question whether there are determinate truths about what an undetermined agent would do in circumstances that never occur. Another can question how such truths constrain divine action. Those are questions about the defense's machinery. They cannot be settled merely by repeating that God is omnipotent.