Freedom and the problem of evil › What transworld depravity does and does not say

Plantinga introduces transworld depravity to develop the possibility that God cannot actualize a world containing moral good without moral evil. The technical definition uses possible persons, their essences, and counterfactuals of freedom. An essence, in this setting, specifies an individual's essential identity. The argument concerns which possible persons God could create, not just the people who happen to exist now.

In outline, consider each possible world in which a person is significantly free and always acts rightly. Transworld depravity requires an obstacle involving what that person would freely do if God actualized an appropriate portion of that world: at some morally significant choice, the person would go wrong. Thus an always-right history's being possible does not ensure that God can actualize it through that person's free choices.

The definition does not say that the person does wrong in every possible world. Indeed, it is formulated by considering worlds where the person freely does only what is right. It also does not say that the person makes the same wrong decision in every circumstance. Different proposed worlds can encounter different obstacles.

The defense then considers the possibility that every creaturely essence suffers from transworld depravity. If that is possible, a world with morally significant creaturely freedom but no wrongdoing might be unavailable for God to actualize, even though such a world is not contradictory in itself. The quantifier matters: describing only the depravity of actually existing people would leave open creating other possible people.

Plantinga needs this scenario to be possible for his defense. He does not establish that every possible creature actually has transworld depravity. Nor does the argument make evil a necessary feature of all reality. God might create no significantly free creatures. The proposed reason for accepting the risk concerns the value of such creatures and their freely produced moral good.

This is also why the square-circle comparison has limits. A causally determined yet libertarian-free decision is contradictory under the stipulated description. A free decision that happens to be right is not. The more demanding question about God's options requires the counterfactual argument, rather than a verbal analogy with an impossible shape.

There is a further distinction between describing an available option and requiring God to select it. Even if a world with some free wrongdoing were available, a defense would still need the moral premise that choosing such a world could be permissible. A fact about what creatures would do supplies no automatic conclusion about what God ought to permit. Conversely, identifying a good that could justify permission would not establish that the relevant history is available to actualize. The moral and modal parts of the defense need to fit together. Treating either as a substitute for the other would leave the compatibility claim underargued.