Problem of Evil

The problem it answers

How can the existence of suffering in the world be reconciled with the existence of a God who is omnipotent (able to prevent any evil), omniscient (aware of every evil), and perfectly good (motivated to prevent every evil)? If God has all three attributes and an evil occurs, then either God could not prevent it (so God is not omnipotent), or God was unaware of it (so God is not omniscient), or God was not motivated to prevent it (so God is not perfectly good). The existence of large-scale evil — the Holocaust, the suffering of children, natural disasters that kill thousands — makes the inconsistency acute.

The problem is the most-discussed single argument against theism in the Western philosophical tradition. The earliest formulation is attributed to Epicurus in the fourth century BCE; the canonical modern formulation is Hume's in the Dialogues Concerning Natural Religion (1779); the major twentieth-century formulations are J. L. Mackie's logical version (Evil and Omnipotence, 1955) and William Rowe's evidential version (The Problem of Evil and Some Varieties of Atheism, 1979). The major theistic responses run from Augustine's free will defense through Aquinas's integration of providence and contingency to Leibniz's Theodicy (1710) and the contemporary work of Alvin Plantinga, Marilyn McCord Adams, and Eleonore Stump.

The core claim

The core claim has three parts:

The traditional attributes of God appear mutually incompatible with the existence of evil. Given omnipotence, omniscience, and perfect goodness, the existence of any evil in a world created by such a God appears to be impossible.

Large-scale evil exists. Not just minor inconveniences but suffering: physical pain, premature death, moral horror, the suffering of beings who could not have deserved it (especially children and non-human animals).

Therefore the traditional theistic conception of God is either inconsistent or false. Either the attributes are revised (some form of process or open theism), or the existence of evil is denied (a position no one defends), or the conjunction of the attributes is shown to be compatible with evil through a theodicy or defense.

History in one paragraph

The earliest formulation is the Epicurean trilemma attributed to Epicurus (though the attribution is contested and the earliest surviving statement is by Lactantius in the early fourth century CE): Is God willing to prevent evil but not able? Then he is not omnipotent. Is he able but not willing? Then he is malevolent. Is he both able and willing? Whence then is evil? Augustine developed the major Christian responses in On Free Choice of the Will (composed 388–395) and the City of God (413–426), arguing that evil is a privation of being (privatio boni) and that moral evil arises from the misuse of free will. Thomas Aquinas integrated the Augustinian framework with Aristotelian metaphysics in the Summa Theologiae. Leibniz's Theodicy (1710) gave the canonical modern theistic response, arguing that this is the best of all possible worlds. Voltaire's Candide (1759), written after the Lisbon earthquake of 1755, satirized the Leibnizian position. Hume's Dialogues Concerning Natural Religion (1779) gave the canonical modern statement of the problem. J. L. Mackie's Evil and Omnipotence (1955) revived the problem in twentieth-century analytic philosophy in its logical form; Alvin Plantinga's God, Freedom, and Evil (1974) developed the free will defense that became the dominant theistic response. William Rowe's The Problem of Evil and Some Varieties of Atheism (1979) developed the evidential version that has dominated the contemporary literature.

The logical version

The logical problem of evil, as formulated by Mackie, claims that the existence of any evil at all is logically incompatible with the existence of an omnipotent, omniscient, perfectly good God. The argument: an omnipotent being could prevent any evil; an omniscient being would know how to prevent it; a perfectly good being would be motivated to prevent it; so the existence of such a being entails the non-existence of evil; but evil exists; so such a being does not exist.

The logical version is widely taken to have been defeated by Plantinga's free will defense (1974). Plantinga shows that the existence of God and the existence of evil are not logically incompatible if it is possible that God could not have created a world containing significant moral good without also containing moral evil. The argument requires only that this scenario be possible, not that it be actual.

The defense uses Plantinga's distinctive concept of transworld depravity: it is possible that for every essence of a created person, that essence is transworld depraved — in every world in which the person exists and is significantly free, the person commits at least one moral evil. If this scenario is possible, then God's creating a world with significantly free creatures necessarily includes creating a world with some evil. The free will defense does not claim that this scenario is actual; it claims only that the bare possibility shows that the logical problem fails.

Most contemporary atheist philosophers have accepted that the logical problem is defeated and have shifted to the evidential version.

The evidential version

William Rowe's 1979 paper introduced the version that has dominated the contemporary literature. The argument: even if the existence of some evil is logically compatible with the existence of God, the existence of certain kinds and quantities of evil provides strong evidence against the existence of God. Rowe's canonical example is the fawn that dies slowly in a forest fire, alone, in pain, with no apparent benefit to anyone. Such suffering is gratuitous — it appears to serve no greater good and to be preventable by an omnipotent being without loss. The existence of gratuitous evil is evidence against the existence of a God who would prevent gratuitous evil.

The argument does not claim deductive certainty; it claims that the existence of gratuitous evil makes theism less probable than atheism. The probabilistic structure makes the evidential version harder to dismiss than the logical version; even if every individual case of apparent gratuitous evil might serve some unknown greater good, the cumulative force of many cases weighs against the conjunction of theism with the actual world.

The major theistic responses to the evidential version are skeptical theism (Stephen Wykstra, William Alston, Michael Bergmann) and greater goods theodicies (John Hick, Marilyn McCord Adams).

Skeptical theism

Skeptical theism, developed by Stephen Wykstra in The Humean Obstacle to Evidential Arguments from Suffering (1984) and continued through William Alston, Michael Bergmann, and Daniel Howard-Snyder, argues that we are not in a good epistemic position to judge whether apparently gratuitous evils are in fact gratuitous. An omniscient God might have reasons for permitting evils that we cannot grasp; from our cognitive position, we cannot distinguish between an evil that has no good-producing function and an evil whose good-producing function we cannot see. The inference from we cannot see what good this evil serves to this evil serves no good is unwarranted.

The position is controversial. Critics (Rowe himself, John Beaudoin, Nick Trakakis) argue that skeptical theism, if accepted, undermines too much: if we cannot trust our judgments about whether evils are gratuitous, we cannot trust analogous judgments about other matters where we similarly lack a God's-eye view. The position is alleged to produce a generalized skepticism that destroys moral reasoning along with the inference from gratuitous evil.

Theodicies

A theodicy is an attempt to specify the goods that justify God's permission of evil. The major theodicies include:

The free will theodicy (Augustine, developed by John Hick, Richard Swinburne): moral evil exists because God created creatures with free will, and free will is a sufficient good to justify the risk of misuse.

The soul-making theodicy (John Hick's Evil and the God of Love, 1966): the world is designed not as a hedonistic paradise but as an environment in which moral and spiritual growth becomes possible. Evil is required for the development of virtues that could not exist in a world without challenge.

The Augustinian privation theodicy: evil is not a positive reality but a privation of being. God did not create evil; evil is the absence of good that follows from the misuse of free will or from the metaphysical structure of finite created reality.

The greater goods theodicy (Marilyn McCord Adams's Horrendous Evils and the Goodness of God, 1999): God's permission of even horrendous evils is justified by the participation of created persons in the divine life through the beatific vision.

Each theodicy has defenders and critics. The contemporary literature on theodicy is one of the most active areas of analytic philosophy of religion.

Common confusions

The problem of evil is not the problem of pain. The problem is not that pain exists (which might serve various goods like warning of injury) but that suffering exists in quantities and kinds that appear to exceed what could be justified by any goods such suffering might produce.

The free will defense is not the free will theodicy. A defense (Plantinga) shows that the existence of God and evil are logically compatible without claiming that the proposed explanation is true; a theodicy (Hick, Swinburne) claims that the proposed explanation actually accounts for evil. The defense responds to the logical problem; the theodicy responds to the evidential problem.

The problem applies to specific conceptions of God. Process theology and open theism revise the divine attributes in ways that modify the problem. The problem in its classical form applies most directly to classical theism.

Live debates

Whether skeptical theism is a coherent position or a counsel of despair. The contemporary debate centers on whether the epistemic humility skeptical theism counsels is principled or merely convenient.

Whether soul-making theodicies adequately address the suffering of non-human animals and infants. Non-human animals and infants cannot undergo soul-making in the relevant sense; their suffering presents a particular challenge for the soul-making theodicy.

Whether the problem of evil is best understood as a theoretical argument or as an existential challenge. Some contemporary philosophers (especially in the continental tradition through Levinas and Paul Ricoeur) argue that the problem cannot be adequately addressed by theoretical theodicies because the suffering at issue is not a theoretical puzzle but an existential challenge to faith.

Contemporary engagement

The contemporary literature is substantial. Alvin Plantinga's God, Freedom, and Evil (1974), J. L. Mackie's The Miracle of Theism (1982), William Rowe's papers collected in Can God Be Free? (2004), Marilyn McCord Adams's Horrendous Evils and the Goodness of God (1999), Eleonore Stump's Wandering in Darkness (2010), John Hick's Evil and the God of Love (1966), Richard Swinburne's Providence and the Problem of Evil (1998), and the work of Peter van Inwagen, Daniel Howard-Snyder, Michael Tooley, and Trent Dougherty constitute the major recent literature. The Oxford Handbook of the Problem of Evil (Meister and Moser, eds., 2017) anchors the introductory literature.

Further reading

• Augustine — the canonical Christian formulator of the privation response
• Aquinas — the major Thomist integrator
• Hume — the canonical modern critic of theistic responses
• Leibniz — the author of the Theodicy and the best of all possible worlds doctrine
• Ontological Argument — the major argument for God's existence
• Cosmological Argument — the other major argument for God's existence
• Free Will — the concept the free will defense and theodicy presuppose
• Original Sin — the related Christian doctrine that bears on the explanation of human moral evil

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