In the philosophy of religion, the "problem of evil" is the problem of reconciling the existence of evil or suffering in the world with the existence of an omniscient, omnipotent, perfectly good God. In Essais de Théodicée sur la bonte de Dieu, la liberté de l'homme et l'origine du mal, a well-known essay written in 1710, Leibniz introduced the term "theodicy" to describe the formal study of this subject.

See also Logical and evidential arguments from evil.

Table of contents
1 Defining the problem
2 Summary of proposed resolutions
3 Analysis of these solutions

Defining the problem

The problem arises from the supposition that a perfectly good God would not intend that evil or suffering exist in the world and that an omniscient and omnipotent God should be able to arrange the world according to his intentions. Since evil and suffering manifestly exist, it would seem that God either intends them to exist and is therefore not perfectly good; or is not omniscient enough to foresee all evil and suffering, or is not omnipotent enough to arrange the world entirely as he intends so as to avoid evil and suffering.

Summary of proposed resolutions

Theodicy is a project to refute the problem of evil and similar arguments against the existence of God, by providing good justifying explanations that reconcile God's existence to the more troubling features of the world.

Resolutions to the problem of evil generally entail one of the following:

  • What humans consider evil or suffering is an illusion or unimportant.
    • Events thought to be evil are not really so (such as deaths by natural disaster).

  • Evil is the consequence of God permitting humans to have "free will", or God may intend evil and suffering as a test for humanity. Without the possibility to choose to do good or evil acts humanity would be nothing but robots.

  • Evil is the consequence, not cause, of people not observing God's revealed will. Universal reciprocated love would solve most of the problems that lead to the evils discussed here.

  • Believe that God's divine plan is good. What we see as evil is not really evil; rather, it is part of a divine design that is actually good. Our limitations prevent us from seeing the big picture.

  • God is a righteous judge; people get what they deserve. If someone suffers, that is because they committed a sin that merits such suffering.

  • Suffering is educational. It makes us better people.

  • Evil is one way that God tests humanity, to see if we are worthy of His grace.

  • Evil and pain exist in this world only. This world is only a prelude to the afterlife, where no pain will exist. The scales of justice are balanced in the afterlife.

  • Evil is not actually real. Rather, it is only a condition of not enough goodness.

  • Solve the dilemma by removing one of the conflicting assumptions: Drop either the assumption that God is omniscient, or omnipotent, or perfectly good. See the entry on the subject of God and omnipotence for more details on this point.

  • Religions such as Gnosticism and Manichaeism, and even some Christian groups, dispense with the issue by embracing various forms of dualism, in which God is opposed by an evil counterpart, and is therefore not omnipotent.

  • Atheists regard the problem of evil as a non-problem, since they believe that God does not exist, and that statements about God are therefore invalid or meaningless. Some atheists believe that the problem of evil can be used to prove that God does not exist by the method of reductio ad absurdum.

Analysis of these solutions

The following are detailed analyses of the above stated solutions.

The free will defense

Assume that both God and Man possess ultimate free will. Why should free will lead to evil? The traditional answer is that humans are corrupt at heart, and they consequently choose to harm their fellows, but that would assume a will that is evil rather than free. It is said to be true that, in order to be free, we must do evil, for God is traditionally said to be both free and morally perfect. Rather, as a matter of contingent fact, humans happen to choose evil by their exercise of freedom. And if God were to 'get involved' and start influencing human actions for the better, then the actions wouldn't be free any longer. Human freedom means that God cannot guarantee human perfection. (See incompatible-properties arguments).

Why should it be better for God to respect human freedom? What's so great about free will? The response is that free will is what makes us valuable moral agents, and that, if God were to deny us our freedom, human society would be like an assemblage of robots. Perhaps there would be some value in such a world, but it is said to be nothing compared to the free moral agency possessed by God and actual humans. All the cruelty that we humans freely perform is indeed regrettable, but it is a small price to pay for freedom.

No matter how successful this response, it can only explain evil caused by human free will. It does not explain any catastrophic horror that has nothing to do with human choices. Think of earthquakes, floods, and disease -- so-called 'natural evil' or 'acts of God'. We cannot confront a paralyzed, demented, and blind Tay-Sachs child and his despondent parents and then chalk up the entire wretched scenario to free will. No one chose it. Healing that child wouldn't tread on anyone's freedom. At its best, the value of free will is relevant to, and can only excuse God for, a mere portion of the evil we find. Whether of not we call that 'evil', we must stick with the evil that we humans freely create -- so-called 'moral evil'.

But there is another, similar problem. Some instances of moral evil already involve violations of free will -- e.g., rape. For God to step in and deny the violator his freedom would also be to protect the victim's freedom. In such cases, it all comes down to whose free will is more valuable -- which instance of coercion would be worse? And it is morally implausible that the best thing to do is to respect a rapist's freedom to rape unhindered rather than protecting the victim's freedom. So, for a large category of moral evil -- all moral evil involving coercion -- it's automatically implausible that the value of free will can justify God's inaction. We must then narrow the domain of admissible evil yet again.

With the candidate evil suitably restricted, we can ask: Is God off the hook? Many say no. Some deny the existence of free will, and so can dismiss the entire proposal as mere fiction. Compatibilists sometimes attack the essential premise that God cannot influence our choices without thereby cancelling our freedom. After all, compatibilists believe that determinism is consistent with human freedom. And if determinism can allow for freedom, perhaps so can appropriate divine meddling with our decisions. The upshot of these challenges is that, to absolve God, we need a reason to think that he really couldn't influence our choices without cancelling our freedom. The customary theistic appeal is to a libertarian conception of free will, but such a conception is under heavy fire from its rivals.

Another challenge focuses on different ways to interfere with freedom. One way is to 'jump in' and take control of the agent, dictating its every movement and thought. This is the kind of coercion we envision in mad scientist stories. But it might also be the kind of coercion that motivates our above intuition that if God got involved, we'd all be 'robots'. We should remember that there are other, softer kinds of coercion. Look to policemen and jailers. They don't take control of an agent's decisions. They just threaten the agent with physical force and restraint, and carry out their threats if necessary. Policemen and jailers restrict our freedom, but it's a restriction we're willing to accept, for our own protection and safety. Now, return to God. If he were to get involved as a Divine Policeman, making threats and enforcing them, then would we be 'robots'? Seemingly not. Instead, we'd be citizens of a divine nation-state, and a very safe and reliable nation-state at that. But then the moral claim is dubious -- it's no longer clear that God should hold back. Taking total control of our decisions would be wrong, but laying down the law might be right. So why hasn't God done it?

Several further challenges attack the idea that evil-eliminating divine interventions must cancel human freedom. These challenges suggest different ways for God to eliminate evil, all the while leaving our free will untouched -- "innocent interventions". One proposal is that God allow sinful acts, but stop their evil consequences. So if I fire a rifle at your head, God allows me to make the decision, but then makes the trigger stick, or the rifle misfire, or the bullet pop out of existence. Such interventions would, happily, divorce evil choices from the subsequent suffering. Another proposal is for God to fortify humans as to render us less vulnerable to the sins of our fellows. We could be bullet-proof, invulnerable to poison, etc. That way, humans would retain the capacity for evil choices and activities; it's just that such evil behavior would be harmless to the 'victims' and futile for the evildoers.

Human nature defense

Another, more subtle proposal is for God to alter human nature for the better. Now, talk of improving our nature immediately strikes us as coercive -- surely, it would rob us our freedom as moral beings! But remember that we already have a nature, a bundle of tendencies that influences our choices. Now, the most ardent determinist must grant that human nature alone does not determine our choices. But the most ardent libertarian must in turn grant that our choices are significantly influenced by our natures. It is easier for a sociopath to kill a child than it is for the rest of us. It is easier for us to send money to help our children than to help complete strangers. This is true, even if ultimately we each have final say on our decisions. Now note that this human nature is flawed. We are disposed to be cruel and callous in many ways. The world might be a better place if humans shared a more virtuous and generous nature.

But would it violate our freedom for God to have given us a better nature? Perhaps not. We might choose a kinder nature, if, for example, virtue came in pill form. We might wish it were easier for us to do good. This suggests that an improved nature may be in accordance with our free will, and not contrary to it. Moreover, if God exists, then surely he had a large hand in crafting human nature. As long as he's giving us some nature or another, why not shoot for a virtuous nature? If it's wrong to make humans virtuous, then why should it be less wrong to make humans corrupt?

One salient theistic reply is that our corrupt nature is due to the Original Sin of the first human couple. Their free choice changed us for the worse, and for God to change us for the better would be to disrespect their free choice. But this reply raises too many troubling issues of its own. First, the wholesale corruption of mankind was, for Adam and Eve anyway, an unforeseeable consequence of Original Sin; one can no more allege that they truly chose human corruption than that Gavrilo Princip truly chose to plunge Europe into war. Big mistakes don't count as freely chosen outcomes. Second, even if Adam and Eve really did choose human nature for the rest of us, why should their choice count for so much? Don't the rest of us have a say? Invoking Original Sin only makes God look more and more morally confused.

God is not omnipotent or omniscient

The problem of evil only exists when one simultaneously holds that God is omniscient (all knowing), omnipotent (all powerful) and omnibenevolent (all good). The problem of evil does not exist if one gives up any of these three beliefs.

Some schools of the Kabbalah (esoteric Jewish mysticism) argue that the creation of the universe required a self-limitation on the part of God, and that evil is a consequence of God's self-imposed exile from the universe He created. In some readings of this theology, God has deliberately created an imperfect world. The question then arises as to why God would create such a world, and the standard response is to maximize human freedom and free will. Other readings of the same Kabbalistic texts one can hold that this is the best world that God could possibly create, and that God is not omnipotent. Given this reading, the problem of evil does not exist.

In Unitarian Universalism, in much of Conservative and Reform Judaism, and in some liberal wings of Protestant Christianity, God is said to be capable of acting in the world only through persuasion, and not by coercion. God makes Himself manifest in the world through inspiration and the creation of possibility, and not by miracles or violations of the laws of nature. God relinquishes his omnipotence, in order that humanity might have absolute free will. In this view, the problem of evil does not exist.

In Judaism the most popular works espousing this point are from Rabbi Harold Kushner; many of his works have also become popular with Christians as well.

The idea of a non-omnipotent God was developed by philosophers Alfred North Whitehead and Charles Hartshorne, in the theological system known as process theology.

In the Evangelical movement of the Protestant churches, Open Theism (also called Free Will Theism), similarly asserts that God acts only cooperatively, and lacks omniscience concerning the future.

Contemporary philosophy of religion

J. L. Mackie, in his now classic article "Evil and Omnipotence", argued that human freedom is consistent with human perfection, and that God should have opted for both. Mackie asserts that human misconduct is a contingent matter -- we can choose to do good or evil, with both alternatives being possible. He then asks us to imagine a world in which everyone always chooses good and never chooses evil -- a virtuous and sinless world. Finally, he notes that God could have chosen to bring about any possible world, from the one that is actual, to a world in which people choose more wickedly, to the good world Mackie just described. So why not go with the good world? The only reply can be that, in choosing to bring about that world, God would thereby deny humans their freedom. But that can't be true. For if it were, then God would have denied us our freedom by bringing about the actual world. Bringing about a world in which people make choices is not freedom-cancelling, and so God should have brought about a world in which people make better choices. This argument is the seed of contemporary discussions of the logical argument from evil, which aims to show that theism and evil are logically incompatible.

Alvin Plantinga, in a response that has also achieved 'classic' status, rebuts Mackie. Plantinga's celebrated "free will defense" argues that evil is consistent with God's existence, because there are some possible worlds that God cannot bring about. This seems curious enough, if we assume that God is omnipotent. Shouldn't he be able to bring about any possible world he wants? But Plantinga reminds us that there are always trivial limits on omnipotence -- God can't make 2+2=5 or create a married bachelor. Plantinga's trick is stretching these trivial limits to very non-trivial results.

Step one: Plantinga proposes that there are logical truths -- so-called "counterfactuals of freedom" -- about our free choices in various possible situations, with one choice dictated for every situation. On Plantinga's example, where S is a situation in which Curley is free to take or refuse a bribe, it is either true that "If Curley were to be free in S, he would take the bribe" or "If Curley were to be free in S, he would refuse the bribe" (assume that exactly one can be true). These truths about what we would freely do in possible situations help make us what we are, and are timelessly and necessarily true -- and so, crucially, out of God's hands. Consequently, if the first proposition is true (and Curley would take the bribe), then God cannot bring about the possible world in which Curley refuses the bribe. God can only bring about S and sadly watch Curley's freely chosen venality manifest itself, as timelessly reported by that unchangeable counterfactual of freedom.

Step two: Plantinga argues for the possibility of a person who will sin at least once, no matter what situation God puts him in. Such a person suffers from so-called "transworld depravity". Though he can choose to do good in each situation, though it is possible that he do good in each situation, it is nevertheless true that he will choose to sin, a sad fact reported by his counterfactuals of freedom. And God can do nothing to bring about the sinless possible worlds -- that's up to the sinner, who will, as a matter of fact, choose otherwise.

We've arrived at the conclusion that perhaps even God cannot bring about Mackie's virtuous and sinless worlds. God may be omnipotent, but he can't change people's free decisions, and he can't change the fact that they will freely choose as they do. And if people will make nasty choices, then those possible worlds in which they choose good are beyond God's reach. Plantinga proposes that perhaps all persons suffer from transworld depravity, that perhaps the actual world, though not the best possible world, is the best one that God could bring about, if he is to respect the free choices of the creatures therein. Natural evil? Perhaps it's also the result of sinful actions -- the actions of invisible, powerful moral agents like demons. And this scenario is one in which God's moral perfection is squared with having created a horrid world like our own.

(Here another problem arises, related to God's claim (in many religions) that, after the end of the world, a paradise will be created where evil is defeated. The whole argument that God in his omnipotence could not create the "virtuous sinless world" described above seems to be contradicted by his own claim to plan to do this very thing! Heaven is the promised paradise of infinite bounty that fully matches the criteria of this virtuous sinless world. If such a world is not possible, then God is lying about the promise of Heaven. If such a world is possible, and God plans to make one world that way, why wasn't our world also made this way?)

One recent, friendly response to Plantinga is from Daniel Howard-Snyder and John O'Leary-Hawthorne. They claim that, to show the compatibility of theism and evil, Plantinga needs to support the possibility of his sketched scenario -- it mustn't be reasonable to doubt its possibility. And they claim that the possibility of all persons being transworld depraved is unsupported. After all, there is another prima facie possibility, that all persons are in fact transworld sanctified (and so would do no wrong). Both 'possibilities' seem equally possible, and since they rule each other out, only one of them can be possible. Thus it is reasonable to doubt the possibility of either, and it is reasonable to doubt that Plantinga's scenario is possible; so it is reasonable to doubt that God really is consistent with evil. The two critics take to repairing Plantinga's argument, by replacing the "it is possible that" propositions with similar "for all we reasonably believe, it is possible that" propositions. The conclusion is then not that theism and evil are compatible, but that, for all we reasonably believe, theism and evil are compatible. The compatibility is not proven, but the incompatibility isn't reasonable, either. Mackie is still rebutted.

Another, stronger challenge comes from Richard Gale. In Plantinga's scenario, God's decisions cause human behavior and the psychological makeup whence that behavior stems; consequently, Gale maintains, human freedom gets cancelled by God's decisions. Ironically, then, Plantinga's "free will defense" story is a story without human freedom. Now, as Gale notes, Plantinga's God can't change peoples' counterfactuals of freedom; the truth of these propositions is up to the relevant people. But, by Plantinga, God does decide which possible persons get actualized, knowing full well their counterfactuals of freedom; it's up to God who gets to exist and then do their stuff. Moreover, God crafts his creatures' psychological makeup, which in turn exercises significant influence over their decisions. This is freedom-cancelling, even if our psychology doesn't determine our decisions, for it makes God like a mad scientist who implants a test subject with new dispositions and preferences to make her more agreeable. And to decide who gets instantiated is to be a sufficient cause of what decisions get made, even if the persons themselves are sufficient causes in their own right. The result is that Plantinga's God is in charge of too much, robbing humans of their freedom. Or so Gale avers.

In his book The Problem of Pain pop theologian C. S. Lewis called pain "God's megaphone to rouse a deaf world".

(responses to Plantinga, Swinburne, all to come)

Holocaust theology

Main article: Holocaust theology

In light of the magnitude of evil seen in the Holocaust, many people have re-examined the classical theological views on God's goodness and actions in the world. How can people still have any faith after the Holocaust? There is a separate entry which discusses the theological responses that people have had in response to the Holocaust.

See also: Logical and evidential arguments from evil, Book of Job, The problem of Hell