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Category: Philosophy
Type: Philosophy of Religion / Ethics
Origin: Epicurus (c. 341–270 BCE), reformulated by David Hume (1711–1776) and others
Also known as: Theodicy Problem, Epicurus’ Riddle, Evidential Problem of Evil
Quick AnswerThe Problem of Evil asks how an omnipotent, omniscient, and omnibenevolent God can coexist with the existence of suffering and evil in the world. It remains one of the most discussed challenges to theistic belief.

What is the Problem of Evil?

The Problem of Evil is not a single argument but a family of challenges that question the logical or evidential compatibility between the existence of God (as traditionally conceived) and the existence of evil. The traditional concept of God includes three attributes: omnipotence (all-powerful), omniscience (all-knowing), and omnibenevolence (all-good). The problem arises because these three attributes, taken together, seem incompatible with the manifest existence of suffering, cruelty, and natural disasters. The classic formulation, attributed to the ancient Greek philosopher Epicurus, captures the tension in a logical trilemma:
“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? Then whence cometh evil?” — Epicurus (paraphrased by David Hume)
This is sometimes called the “logical problem of evil”—it claims that the existence of God and the existence of evil are logically contradictory. A related but distinct challenge is the “evidential problem of evil”: even if not strictly contradictory, the sheer amount and intensity of suffering in the world makes God’s existence improbable.

The Problem of Evil in 3 Depths

  • Beginner: You notice the tension: a good parent wouldn’t let their child suffer preventable harm. Yet natural disasters and diseases cause immense suffering apparently without divine intervention. This intuitive conflict is the starting point.
  • Practitioner: You distinguish logical vs. evidential formulations. Logical: is God + evil a contradiction? Evidential: does evil make God unlikely? You also separate “natural evil” (disease, earthquakes) from “moral evil” (human cruelty), as different theodicies address them differently.
  • Advanced: You engage with technical debates: skeptical theism (we cannot know God’s reasons), free will defenses (moral agency requires libertarian freedom), soul-making theodicies (suffering builds character), and comparative assessments across worldviews.

Origin

The Problem of Evil has ancient roots. Epicurus (341–270 BCE) articulated an early version in his lost work On the Gods, preserved through later citations. The problem reappeared in medieval Christian thought through thinkers like Augustine (354–430 CE), who developed influential responses centered on free will and the “privation” theory of evil (evil as absence of good, not a positive force). The modern formulation owes much to David Hume, who presented a powerful version in his Dialogues Concerning Natural Religion (1779). Hume’s character Philo argues that the mixture of good and evil in the world is more consistent with an indifferent or limited deity than with an all-powerful, all-good one. In the 20th century, the logical problem received rigorous treatment from philosopher J.L. Mackie (1917–1981), who claimed it constituted a formal disproof of theism. Alvin Plantinga’s free will defense (1974) is widely regarded as showing that the logical problem can be answered—at least, that God and evil are not strictly contradictory—though the evidential problem remains contested.

Key Points

The problem’s structure can be analyzed through several distinctions:
1

Logical vs. Evidential

The logical problem claims God + evil is a contradiction. The evidential problem claims evil makes God improbable. Most contemporary philosophers consider the logical problem answerable; the evidential problem is the live debate.
2

Natural vs. Moral Evil

Natural evil (suffering from disease, natural disasters) is harder to reconcile with a good God than moral evil (human wrongdoing), since natural evil cannot be easily justified by free will—animals and infants suffer without choosing to do so.
3

Horrendous Evils

Philosopher Marilyn Adams argued that some evils—torture, genocide, child abuse—are so destructive that they threaten the very possibility of a meaningful life for victims. These “horrendous evils” pose special challenges for theodicy.
4

Distribution vs. Existence

Some versions focus not on whether any evil exists, but whether its distribution is just: Do the wicked prosper? Do the innocent suffer? This raises questions about cosmic justice that pure abstract theodicy may not address.

Applications

Beyond theology, the Problem of Evil shapes thinking about ethics, suffering, and meaning:

Medical Ethics

The existence of congenital diseases and childhood cancers challenges straightforward views of divine benevolence. This shapes how medical ethicists think about “natural” suffering and the limits of human intervention.

Political Philosophy

The “distributional” aspect—why some suffer far more than others—affects thinking about cosmic justice versus social justice. If God does not ensure fairness, human institutions must bear more responsibility.

Existential Psychology

Viktor Frankl’s logotherapy, developed in Nazi concentration camps, addressed how humans find meaning despite extreme suffering. This is a practical, rather than theoretical, response to the problem.

Comparative Religion

Different traditions handle evil differently: Buddhism denies a creator God; Hinduism incorporates karma and reincarnation; Abrahamic religions develop theodicy. Comparing these reveals how theological assumptions shape ethical responses.

Case Study

Consider the 1755 Lisbon earthquake, which killed an estimated 30,000–50,000 people on a religious holiday. The disaster prompted widespread theological reflection across Europe. Voltaire famously attacked the optimistic theodicy of Leibniz—that this is “the best of all possible worlds”—in his satirical novel Candide (1759). The Lisbon earthquake illustrates several features of the Problem of Evil: it was natural (not caused by human wrongdoing), killed indiscriminately (including devout worshippers), and on a massive scale. Pre-modern theodicies emphasizing God’s particular purposes in individual cases struggled to account for such systematic destruction. The disaster contributed to the secularization of European thought and the development of disaster relief as a human, rather than divine, responsibility. Philosophically, the earthquake sharpened the evidential problem: it provided concrete data about the quantity and distribution of suffering that abstract philosophical arguments had to address. Subsequent theodicies, including process theology and various forms of skeptical theism, developed partly in response to such historical horrors.

Boundaries and Failure Modes

Responses to the Problem of Evil face several common difficulties: The Instrumental Problem: Many theodicies treat suffering as instrumental to some greater good (soul-making, free will, etc.). Critics argue this instrumentalizes victims—using their pain as means to ends—and may fail to account for gratuitous suffering that seems to serve no redemptive purpose. The Modal Problem: If God is genuinely omnipotent, why couldn’t he achieve his good ends without evil? Free will defenses must explain why a world with free creatures who never choose evil is impossible, not just unlikely—a metaphysically demanding claim. The Empirical Problem: Even if the logical problem is solved, the evidential problem remains: given the sheer quantity of suffering, is theism probable? Skeptical theism—claiming we cannot know God’s reasons—risks undermining positive theological claims along with negative ones. The Existential Gap: Intellectual solutions may not address the experiential reality of suffering. The theoretical “answer” to the Problem of Evil and the pastoral response to a grieving person may be very different things.

Common Misconceptions

Correction: Most contemporary philosophers agree the logical problem does not constitute a strict disproof. The evidential problem reduces probability; it does not establish impossibility. Theism remains logically coherent, even if challenged.
Correction: While Augustine’s “privation theory” has theological significance, it does not solve the practical problem. Suffering remains real and destructive whether evil is a “positive” force or an absence. The theory shifts metaphysical classification without eliminating experiential harm.
Correction: Atheists must still explain why humans care about suffering, why moral norms exist, and how to address evil without divine resources. The problem transforms, rather than disappearing. Secular accounts of evil face their own challenges.
The Problem of Evil intersects with multiple philosophical and theological themes:

Free Will

The Free Will Defense argues that moral agency requires libertarian freedom, which makes possible both good and evil choices. God cannot create free creatures who never choose evil without compromising their freedom.

Theodicy

Theodicy attempts to justify God’s goodness despite evil. It differs from defense (showing logical compatibility) by offering positive explanations of why God permits suffering.

Skeptical Theism

This response argues that human cognitive limitations prevent us from knowing whether God has good reasons for permitting apparently gratuitous evil. We cannot see the “big picture” that would justify divine permission.

One-Line Takeaway

The Problem of Evil asks not whether God exists, but what kind of God could coexist with the world’s suffering—and whether we can understand the reasons for divine permission.