Logical Problem of Evil
The Logical Problem of Evil is the strong form of the problem: the claim that the existence of any evil is strictly inconsistent with the existence of an omnipotent and wholly good God. The canonical modern statement is J. L. Mackie‘s 1955 paper “Evil and Omnipotence,” which argued that the propositions
- God is omnipotent.
- God is wholly good.
- Evil exists.
are jointly inconsistent, and that any theistic response would have to give up one of them or smuggle in a special definition of one of the divine attributes.
The standard response is Alvin Plantinga‘s Free Will Defense, which argues that even an omnipotent God could not actualize a world containing genuine free will and no evil, because the freely chosen actions of created beings are not strictly within God’s control. The defense uses the modal logic of possible worlds and is widely thought to have shown that strict logical inconsistency cannot be established.
J. L. Mackie himself, in The Miracle of Theism in 1982, conceded the logical version while pivoting to an evidential one. Most contemporary atheist philosophers who continue to press the problem do so in its evidential form, following William Rowe rather than the early Mackie.