Abstract

Alvin Plantinga’s solution to J. L. Mackie’s logical problem of evil invokes possible-worlds metaphysics. There are reasons for thinking that the solution is, at least, problematic. Difficulties emerge in the attempts to answer four related questions. Can God’s necessary existence, understood in terms of possible-world metaphysics, make God’s actual existence impossible to explain? Can an omniscient being with knowledge of the contents of every possible world prove ignorant of the consequences of his creative acts? Can an immoral action performed by an agent suffering from “transworld depravity” also be free in the libertarian sense? Does the possible-worlds interpretation of libertarian freedom generate a vicious infinite regress? Special focus is on the possibility, advanced by Plantinga, that there are possible worlds that even an omnipotent being cannot create. Plantinga’s views are contrasted with those of Thomas Aquinas.