Mackie on Evil and Omnipotence: The Logical Inconsistency

The Quote

"In its simplest form the problem is this: God is omnipotent; God is wholly good; and yet evil exists... These propositions are, at first sight, inconsistent: if they are all true, God cannot be wholly good, or cannot be omnipotent... I think, however, that we can show that there is no valid solution of the problem." So J.L. Mackie, in the pages of Mind in 1955, gave the logical problem of evil its classic modern formulation.

Context

Mackie's "Evil and Omnipotence" appeared in Mind, the leading philosophy journal in the English-speaking world, in April 1955. The article was a turning point. Before Mackie, the problem of evil was a difficulty for theism — a challenge that thoughtful believers had to wrestle with — but it was not, in the philosophical literature, presented as a refutation. Mackie presented it as a refutation: a demonstration that the central propositions of classical theism are logically inconsistent, so that the theist is committed to a contradiction. The article was short, sharp, and enormously influential. It defined the terms of the debate for the next half-century.

Meaning

The argument rests on the "inconsistent triad": God is omnipotent, God is wholly good, and evil exists. Mackie's claim is that these three propositions cannot all be true together. The reasoning is straightforward. A wholly good being eliminates evil as far as it can. An omnipotent being can eliminate evil altogether. So if a wholly good, omnipotent being exists, evil does not. But evil does exist. Therefore a wholly good, omnipotent being does not exist. The argument, if it works, shows not that theism is improbable but that it is logically incoherent — that the concept of the classical God is self-contradictory in a world with evil. This is the strongest form the problem of evil can take, and it is the form Mackie gave it.

Mackie's Critique of the Solutions

Mackie did not stop at stating the inconsistency; he examined the main theistic responses and argued that none of them works. The first is the free will defense: evil is the price of genuinely free creatures, which are better than automata. Mackie's response is that an omnipotent God could have made free creatures who always choose the good — if freedom is compatible with the determinate choice of the good, then there is no contradiction in a world of free creatures who never sin, and an omnipotent God could have created it. The second is the soul-making theodicy: evil is the condition of moral and spiritual growth. Mackie's response is that an omnipotent God could have made creatures who are already fulfilled, without the need for the struggle that evil enables — that the goods of soul-making do not require evil, if God is omnipotent. The third is the appeal to mystery: God has reasons we cannot know. Mackie's response is that this gives up the claim to rational theism; if the theist must appeal to mystery, then theism is not a rational position but a faith that has abandoned the ground of reason. Mackie concluded that none of the solutions is valid: the inconsistency stands.

Philosophical Interpretation

Mackie's argument is the logical problem of evil, as distinct from the evidential problem. The logical problem claims that the existence of evil is inconsistent with the existence of the classical God — that theism is logically incoherent. The evidential problem claims only that the existence of evil makes theism improbable — that theism is rationally unbelievable, even if not strictly contradictory. The distinction matters: the logical problem is stronger, and harder to sustain, because it must show that no possible world contains both God and evil. The evidential problem is weaker, and more resilient, because it need only show that the actual world, with its particular evils, is more likely on atheism than on theism. Mackie's article took the stronger form, and the stronger form has been the focus of the debate since. The most influential response came from Alvin Plantinga, in God, Freedom, and Evil (1974) and later work. Plantinga argued that the free will defense is sufficient to show the consistency of God and evil — not by proving that God exists, but by showing that Mackie's claim of inconsistency cannot be sustained without additional premises that the theist need not accept. Plantinga's argument turns on the possibility of "transworld depravity": the claim that any possible creature with significant freedom would, in at least one possible world, do wrong — so that even an omnipotent God could not have actualized a world with free creatures and no evil. If this is even possible, then Mackie's claim of inconsistency fails. The consensus in the contemporary philosophy of religion is that Plantinga's response defeated the logical problem — that the existence of evil is not logically inconsistent with the existence of the classical God. The evidential problem, however, remains.

Legacy

Mackie's article is the most cited paper in the philosophy of religion of the twentieth century. It defined the logical problem of evil, provoked the free will defense in its modern form (Plantinga's), and set the terms of the debate that continues to the present. The deepest consequence of the article is the distinction between the logical and evidential problems — a distinction that did not exist in clear form before Mackie and that has shaped every subsequent discussion. The logical problem asks whether God and evil are compatible; the evidential problem asks whether, given the actual evils of the world, theism is probable. The logical problem has been largely answered (most philosophers agree that Plantinga showed the consistency of God and evil). The evidential problem — the problem of the amount and distribution of evil, of the suffering that seems pointless — remains the strongest challenge to theism, and it is the problem the contemporary debate wrestles with. Mackie's article is the origin of this distinction, and it remains the starting point of every serious treatment of the problem.

The Deeper Lesson

The deepest lesson of Mackie's argument is not that God does not exist but that the theist cannot rest with the mere assertion that God is good and powerful. The existence of evil is a real difficulty for theism, and the theist who refuses to face it is not defending the faith but evading its hardest question. Mackie's wisdom is the wisdom of the honest challenger: state the problem clearly, examine the responses carefully, and do not let the theist off the hook with vague appeals to mystery. The corresponding wisdom for the theist is the wisdom of the thoughtful respondent: take the problem seriously, give the best response available, and be honest about what the response does and does not show. The free will defense, the soul-making theodicy, the appeal to mystery — each has its strengths and its limits, and the wisdom is in knowing them. The problem of evil is not going to be solved by a slogan, in either direction; it requires the patient, clear-headed work that Mackie modeled and that the debate has continued ever since.

Relations

This quote is the classic modern formulation of the problem of evil and the strongest version of the philosophy of atheism's challenge to theism. It belongs to Mackie, was answered most influentially by Plantinga on the free will defense, and engages the Augustinian and Hickian theodicies. It bears on the wisdom of confronting evil and the wisdom of God.

Sources

1. "Problem of Evil." Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/evil/
2. J. L. Mackie. "Evil and Omnipotence." Mind 64 (1955): 200-212.
3. Alvin Plantinga. God, Freedom, and Evil. Grand Rapids: Eerdmans, 1974. (The classic response to Mackie.)