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A Simple Statement of the Problem of Evil


Believers tell us that God is good. Not only is he good, he is perfectly good, supremely good, as good as can be. God is also powerful. Not only is he powerful, he is omnipotent—that is, all-powerful. Most theologians and philosophers have taken “all-powerful” to mean that God can do anything except make a contradiction true. So making a round square, a married bachelor, or an odd number that is evenly divisible by two are things that God cannot do. “Round square,” “married bachelor,” and “odd number evenly divisible by two” are contradictions in terms, so for these things to exist, a contradiction would have to be true.[1] However, anything else—any x for which we can say “God does x” without contradicting ourselves—God can do. He can, for instance, heal the sick, raise the dead, part the sea, or turn water into wine.

God is also said to be the creator of the universe. This means that everything that exists is created either directly or indirectly by him. God creates directly simply by willing something to be, as the first chapter of Genesis depicts: God says “Let there be…” and it is so. God indirectly creates in two ways. First, when he creates the universe he creates matter and energy and the laws that govern them. Then, through the lawful, orderly operation of natural processes, new things are brought into existence. For instance, if God creates the laws and conditions underlying the process of evolution, then evolution becomes the indirect means whereby God creates organic creatures. Scientists of the 19th century therefore distinguished between “primary causes”—God’s direct actions—and “secondary causes”—the physical processes whereby God’s aims were achieved in the natural world.

Another way that God indirectly creates is by bringing into existence intelligent, sentient creatures that are endowed with free will and so act on their own to bring about new things. When some prehistoric human invented the wheel, it was indirectly created by God since humans are God’s creatures and God endowed them with the ability to make new things. So whatever is brought about by nature or humans is indirectly created by God.

Note, however, that nature and humans often bring about very bad things. The natural world, operating in accordance with its own impersonal laws, produces diseases, birth defects, parasites, earthquakes, hurricanes, tornadoes, tsunamis, explosive volcanic eruptions, asteroid impacts, and the whole system of “nature red in tooth and claw” whereby creatures survive only by painfully destroying other living, feeling creatures. Human beings misuse their free will to do terrible things to one another and to other creatures. They commit massacres, genocides, and acts of terrorism; they torture, abuse, rape, swindle, steal, cheat, oppress, exploit, lie, and deceive. Following scholarly precedent, let us call the bad things brought about by nature “natural evil,” and the bad things brought about by humans’ free actions “moral evil.” Since God created nature and human beings, it must follow that God, at least indirectly, is the creator of both natural and moral evil. Perhaps it is offensive to speak of God as the creator of evil. Nevertheless, we must at least say that God does not prevent evil though, being all-powerful, he could.

This concept of God therefore seems to unavoidably require three things to be true:

(1) God is perfectly good.
(2) God is all-powerful.
(3) God does not prevent the existence of natural and moral evil.

Yet as the ancient Greek philosopher Epicurus is said to have observed long ago, these three claims seem to form an inconsistent set. That is, any two of them could be true, but all three of them cannot. His reasoning was this: If God can prevent evil, then if he is perfectly good he does prevent evil. If God is all-powerful, then he can prevent evil. Yet God does not prevent evil. Thus we must conclude that either God is not perfectly good or not all-powerful. Epicurus’ reasoning is straightforwardly translatable into propositional logic and easily proven valid.[2]

Since Epicurus’ conclusion has the logical form of a disjunction—either God is not all-powerful or he is not perfectly good—apparently believers must choose which disjunct they wish to discard. Should we regard God as less than all-powerful, or less than perfectly good? Some opt for the former, but for defenders of traditional theism—believers in the historical creeds of Christianity, Judaism, or Islam—neither option is acceptable. For traditional theists, God is by definition all-powerful and perfectly good, so to give up either disjunct is to stop believing in a traditional God. The upshot is that Epicurus’ argument implies the nonexistence of such a God. For traditional theists, a god that is not all-powerful or not perfectly good is not God. Hence, the real implication of Epicurus’ argument is that such a God does not exist.

All is not lost for traditional theism, however. If you reject the conclusion of a valid argument, then you must hold that at least one of its premises is false. The only potentially shaky premise in Epicurus’ argument is the first one: “If God can prevent evil, then if he is perfectly good he does prevent evil.” Is this necessarily so? Might God have a morally sufficient reason for permitting some evil? That is, might it be that some evils are necessary for the prevention of even greater evils, or for the achievement of some greater good?

Let’s look more closely at the notion of a “perfectly good being.” A good mother will protect her children, preventing them from suffering when suffering can and should be avoided. A human mother cannot protect against all evils, and even the best mother will let her children undergo some unpleasant experiences. For instance, a painful inoculation may be necessary to prevent an even more painful disease, so the good mother will permit the lesser pain to prevent the greater. Or consider that homework may be drudgery, but that it is necessary for an education, and that an education is a great enough benefit to make the necessary drudgery worthwhile. A good mother will therefore insist that her children do their homework, even when it is painfully tedious for them. Surely, then, a perfectly good being will be one that prevents the existence of as much evil as it can unless that being has a morally sufficient reason for permitting an evil. What could such a morally sufficient reason be? It would arise in situations where permitting an evil is necessary to prevent an even worse evil, or necessary for achieving some good so great that it makes the necessary evil worthwhile.

But what if this perfectly good being is also all-powerful, as God is supposed to be? Such a being could prevent any evil, and so an evil will exist only if God (the perfectly good, all-powerful creator) permits it to exist. Moreover, God—being perfectly good—will permit an evil only if he has a morally sufficient reason to allow it to exist. (Again, a “morally sufficient reason” obtains in a situation where permitting an evil e is necessary to prevent a greater evil, or else necessary to achieve a good great enough to make e worthwhile). Let’s call all of the evils that really exist (in the past, present, or future) “actual evils.” It follows that principle P below must be true:

P: If God exists, then for every e, if e is an actual evil, then God has a morally sufficient reason for permitting e.

Proposition P is expressed as a hypothetical proposition. Let’s separate out the consequent of that proposition, and call it proposition Q:

Q: For every e, if e is an actual evil, then God has a morally sufficient reason for permitting e.

Further, let’s define a “gratuitous evil” as an evil that not even God would have a morally sufficient reason for permitting. Such an evil is neither necessary to prevent a greater evil, nor necessary to achieve a good great enough to make worthwhile the occurrence of that evil. Hence, if an evil is gratuitous, then God, if he exists, will not permit that evil to become an actual evil. Conversely, if any actual evil is a gratuitous evil, then God does not exist. The crux of the problem of evil is therefore whether any actual evils are gratuitous evils.

One version of the problem of evil—the evidential version—can therefore be put like this: If Q is false, then, since it is the consequent of proposition P, by modus tollens the antecedent of P, “God exists,” must be false. Since we established P by appeal to the basic notions that constitute our idea of God, i.e., that he must be perfectly good and all-powerful, P is clearly true. Q, on the other hand, seems false. The world is full of atrocious evils that, so far as we can tell, are not necessary for the prevention of even greater evils, or for the realization of goods so great that they make worthwhile the occurrence of those atrocious evils. In short, there seem to be innumerable instances of what we have called “gratuitous evils,” evils so senseless and avoidable that God, if he exists, would not permit them. The plethora of apparently gratuitous evils is very good evidence that some actually are gratuitous, so we have very good evidence that Q is false, and thus very good evidence that God does not exist.

Suppose, for instance, that lightning starts a forest fire that destroys thousands of acres, panicking and then burning to death many forest animals. The painful death of many innocent creatures certainly seems to serve no good that an all-powerful being could not have accomplished in some other way, a way that would require less suffering. Of course, ecologists tell us that forests must occasionally burn to stay healthy, so it might be best for humans, as stewards of the earth’s resources, to let some fires burn. Remember, though, that we are not talking about what humans can accomplish given human limitations, but what an all-powerful being can do, and, prima facie—if being all-powerful amounts to anything—surely such a being could devise ways of having healthy forests without periodically causing the anguished deaths of the denizens of the forest.[3]

Examples of apparently pointless evils could be multiplied indefinitely. Some evils are so egregiously awful that no conceivable attendant good would be great enough to justify permitting them. Fyodor Dostoyevsky famously put it this way in The Brothers Karamazov: If you could create a paradise filled with myriads of perfectly happy and morally good creatures (like Heaven, supposedly), yet the price for that paradise was that one small child had to be slowly and hideously tortured to death, would you do it? Tens of thousands of small children die painfully every day in our world. We cannot even begin to imagine what would constitute a great enough good to be bought at such a dreadful price. Nothing in our experience would even begin to qualify.

This is precisely where some theists would object: Why should we expect to be able to conceive of all of the goods that God might accomplish? After all, as Scripture (1 Corinthians 2:9) attests, “as it is written, eye hath not seen, or ear heard, neither have entered into the heart of man, the things which God hath prepared for them that love him.” Perhaps we have so little grasp of what omnipotence can accomplish over vast stretches of time and space that we are just not in a position to say whether or not God can bring about goods so great that they can redeem even the worst evils. Simply put, the evidential argument from evil assumes that the fact that evils appear gratuitous to us is reason to believe that they actually are, but maybe this is not so.

In a newspaper debate on the problem of evil I once had with William Lane Craig, Craig put this theistic response like this:

We aren’t in a good position to assess with confidence the probability (or improbability) of whether God has morally sufficient reasons for permitting bad things. Suffering that appears utterly pointless within our limited framework may be seen to be justly permitted in God’s wider framework. The brutal murder of a child may have a ripple effect through history such that God’s reason for not preventing the evil may emerge only centuries later or in another country. (Dallas Morning News, June 13, 1998)

According to Craig, then, we have no grounds for saying that it is probable or improbable that God has a morally sufficient reason for permitting evil, and so we have no grounds for saying that evils are gratuitous just because they appear so to us. Note, however, that Craig’s statement cuts both ways. Craig wants to deny that the atheist has good reason for saying that proposition Q is probably false, but then these same reasons undercut the theist’s grounds for saying that Q is probably true. Craig’s argument rests upon the alleged unknowability of the opportunities for good that an omnipotent being might have. No matter how gross the evil, Craig thinks that it might—someday, somewhere, somehow—turn out to have been a necessary condition for the achievement of some justifying good. Or, we might reply, maybe not.

Craig’s suggestion is, and can be, nothing more than a speculation, or a statement of faith. Maybe no realizable good (realizable even by God) is good enough to redeem the grossest evils. Or if one is, maybe God could have brought about such good without so much evil (after all, he is all-powerful). If we have no clue what kinds of goods may be achievable, or how achieving those goods could have made evils unavoidable (unavoidable, that is, even for God), then we really can’t say one way or the other.
In short, if Craig’s argument is sound, we all have to be agnostic about proposition Q—theists and atheists alike. None of us is in a position to judge with any confidence whether or not God probably has morally sufficient reasons for permitting evils. In that case, though, don’t we also have to be equally agnostic about God’s existence? Can we even be confident that God could exist? Consider a parallel: Could koalas live in the wild in Texas? Well, since koalas eat only eucalyptus leaves, they can live in Texas only if eucalyptus can grow in Texas. If I can have no information one way or the other about whether eucalyptus trees can grow in Texas, I cannot say whether or not koalas can live wild in Texas. They can (so far as I know) if eucalyptus can grow there, and they definitely cannot if it can’t.

Similarly, if every actual evil is nongratuitous, that is, if an all-powerful perfectly good creator would have a morally sufficient reason for permitting it, then (so far as I know) God could exist. On the other hand, if any (even one) actual evil is gratuitous, that is, if a perfectly good, all-powerful creator would not have a morally sufficient reason for permitting it, then God cannot exist. If, as Craig asserts, we can have no way of knowing with any degree of confidence whether God would or would not have morally sufficient reasons for permitting actual evils, then we have no way of knowing whether God can or cannot exist. Anyone who wants to say that we can have grounds for asserting God’s existence must concomitantly have grounds for holding that no evil is gratuitous, but those who give arguments such as Craig’s seem to deny that we can have grounds for this latter claim.

Couldn’t we, though, have independent evidence for koalas (or God)? If a thriving colony of koalas is located in the Big Thicket, then we know that they can live in Texas even if we don’t have any knowledge about the viability of eucalyptus growing in Texas. Indeed, the presence of koalas would show that there must be eucalyptus trees there even if we haven’t spotted them. Similarly, could we not have independent evidence for the existence of God such that, if the evidence is strong enough, we can be confident that since God does exist, he must have morally sufficient reasons for permitting actual evil? That is, sufficient independent evidence for God could stand the problem of evil on its head: God exists, so the problem must have a solution even if we do not know what it is.

But the viability of this position depends on what sort of evidence one might adduce. The most popular arguments for the existence of God do not conclude that God exists, but that a less specific designer, creator, or first cause exists. For instance, the current “Intelligent Design” movement does not claim to show that the God of Christian faith exists, only that the universe has a nonspecific intelligent designer. Similarly, perhaps the most popular current argument from natural theology is the “fine-tuning” argument. The argument claims that the basic physical constants of the universe are “fine-tuned” for complex life, and that this is probable only if there is an intelligent creator that wants complex life. But what good would such a vague creator or fine-tuner be if its moral attributes were left in doubt? It is precisely those moral attributes that are brought into question by the problem of evil. A fine-tuner or first cause that is not perfectly good cannot be God. The upshot is that natural theology can support a case for theism only if the problem of evil is also solved. Otherwise those arguments cannot establish the existence of God, but at most some nondescript designer, fine-tuner, or cosmic kick starter. So natural theology gives the theist no hope of avoiding a head-on confrontation with the problem of evil.

Arguments such as Craig’s—sometimes called the “unknown purpose defense” (UPD)—are deployed by theists to block atheistic arguments from evil. As I noted with the forest fire example, atheists frequently argue that there are so many apparently gratuitous evils in the world—evils that seem so pointless, avoidable, or overwhelmingly horrible—that surely it is probable that an all-powerful being could, and a perfectly good being would, have prevented at least some of them. Therefore, the existence of so many apparently gratuitous evils is strong evidence against the existence of God. However, by appealing to supposed unknown purposes, theists deny that evils which appear absolutely pointless to us provide any evidence that they really are gratuitous. After all, they allege, we simply cannot know what sorts of goods omnipotence can create, nor can we have any inkling of the complex ways in which present evils are necessary for the realization of those putative goods. By analogy, lab rats cannot begin to comprehend the reasons why they are put through travails in medical research. Perhaps we are no more capable of understanding the travails that God puts us through. This is the conclusion, couched in splendid poetry, of the Book of Job.

Even if appeals to unknown purposes serve to block the atheist’s evidential argument from evil, they have a severe drawback. The unknowability of God’s putative purposes in permitting gross evils applies to theists just as much as it does to atheists. For example, theists must hold that God permitted the Triangle Shirtwaist Factory fire in New York City on March 25, 1911, in which 146 people, mostly girls and young women, either burned to death or jumped to their deaths because of a sweatshop fire. The managers, it seems, had locked the exits to prevent workers from leaving before their shifts had ended. What conceivable good could not have been attained—especially by an omnipotent God—except by permitting this terrible fire? Theists can offer no clue as to what such a good might be, or why it necessitated so gross an evil, but they are nevertheless confident that God does have a morally sufficient reason. On what possible grounds, though, do they base their confidence? Craig asserts that “we aren’t in a good position to assess with confidence the probability (or improbability) of whether God has morally sufficient reasons for permitting bad things.” But then no one would have grounds to conclude that God does have a morally sufficient reason to permit the grossest of evils. And if there are no reasonable grounds for such confidence, then there are no reasonable grounds for holding that a perfectly good and all-powerful being exists, or even could exist.

The UPD is probably the most powerful weapon in the theist’s arsenal for dealing with the problem of evil. Yet, as we have seen, it seems more dangerous to its user than to the intended target. Moreover, it fails even if we concede its main claim. The UPD claims that we cannot appeal to the fact that an evil appears gratuitous as evidence that it actually is. Even if we grant this for the sake of argument, the odds seem to be overwhelmingly against theists with respect to the existence of evil. Suppose that since the first living creatures neurologically advanced enough to suffer pain emerged (far back in the Paleozoic), there have been a trillion (10^12) instances of undeserved, unwanted suffering. The theist must hold that God has a morally sufficient reason for permitting every single one of those trillion instances of suffering. In other words, not one can be gratuitous. Indeed, not one instance of all that suffering could even have been mitigated in the slightest. Obviously, a being cannot be perfectly good if it permits any amount of pointless suffering that it can easily prevent. Hence, if one Diplodocus suffered needlessly in the Jurassic, then God does not exist. Since we have presupposed a trillion instances of unwanted, undeserved suffering over the history of sentient life, the theist must hold that each such instance has nearly a zero chance of being gratuitous, otherwise the probability of the disjunction of these trillion individual probabilities will add up to a very high probability that some evil is gratuitous.[4] What rational grounds could anyone have for being extremely confident that no sentient creature anywhere has ever suffered needlessly? Here I merely assert that theists have no rational basis for such an assurance; the ball is in their court to show that they do.

Some theists will contend that they have already explained why God permits evils, even horrendous ones. Their venerable theodicies attempt to explain the ways of God so that we can see why he permits evil. Among the most famous recent theodicies are those of Richard Swinburne and John Hick.[5] I will pass over the differences between these elaborate proposals, but they both hold that God permits evils to give humans opportunities that they otherwise could not have. Only by overcoming adversity and enduring travails can humans make themselves into compassionate and courageous beings. Indeed, Hick and Swinburne point out that a life with no challenges or discomforts would be a fool’s paradise that could produce nothing but a race of lazy, apathetic egoists. The great souls of history—Martin Luther King, Jr., Louis Pasteur, Albert Schweitzer, Socrates, the Buddha, and so on—attained greatness by overcoming moral or natural evil. The desire to end suffering is a desire to end all that can make life truly significant, all that can make life a glorious, hard-fought victory rather than an insipid indulgence.

While these ingenious theodicies sound persuasive on the surface, they fall far short of dealing with the problem of evil. I think that the final word on all such efforts has been captured eloquently by the major Christian philosopher Alvin Plantinga:

Why does God permit all this evil, and evil of these horrifying kinds, in his world? How can they be seen as fitting in with his loving and providential care for his creatures?… The Christian must concede he doesn’t know. That is, he doesn’t know in any detail. On a quite general level, he may know that God permits evil because he can achieve a world he sees as better by permitting evil than by preventing it; and what God sees as better is, of course, better. But we cannot see why our world with all its ills, would be better than others we think we can imagine, or what, in any detail, is God’s reason for permitting a given specific and appalling evil. Not only can we not see this, we can’t think of any very good possibilities. And here I must say that most attempts to explain why God permits evil—theodicies, as we may call them—strike me as tepid, shallow and ultimately frivolous. Does evil provide us with an opportunity for spiritual growth, so that this world can be seen as a vale of soul-making? Perhaps some evils can be seen this way; but much leads not to growth but to apparent spiritual disaster. Is it suggested that the existence of evil provides the opportunity for such goods as the display of mercy, sympathy, self-sacrifice in the service of others? Again, no doubt some evil can be seen this way…. But much evil seems to elicit cruelty rather than sacrificial love. And neither of these suggestions, I think, takes with sufficient seriousness the sheer hideousness of some of the evils we see.[6]

So Plantinga thinks that Christians should admit that they do not know why God permits evil. He thinks that, despite this, Christians can still have confidence that God does have good reason for permitting evil. But how? How do we penetrate the wall of imponderables raised by Craig and other defenders of the UPD? If the capacities and opportunities of omnipotence are unknown, then they are unknown. None of us can say with any confidence whether God probably does, or does not, have good reasons for permitting evils. So be it. In that case, none of us can say with any confidence that God exists.


[1] For instance, combining the statement “There exists something which is both round and square” with the necessary truth “whatever is round is not square” (which is necessarily true due to the meanings of “round” and “square”) entails both that a round square exists, and that a round square does not exist:

  1. (∃x)(Rx & Sx)                                 Premise
  2. (x)(Rx → ~Sx)                                Premise
  3. (x)(~Rx v ~Sx)                                2, Implication
  4. (x)~(Rx & Sx)                                 3, DeMorgan’s Theorems
  5. ~(∃x)(Rx & Sx)                              4, Quantifier Negation
  6. (∃x)(Rx & Sx) & ~(∃x)(Rx & Sx)  1,5 Conjunction

[2] Let G = God is perfectly good; A = God is all-powerful; P = God prevents evil; C = God can prevent evil. Epicurus’ argument can be proven as follows:

  1. C → (G → P)                                 Premise
  2. A → C                                            Premise
  3. ~P /: ~A v ~G                                 Premise
  4. (C & G) → P                                 1, Exportation
  5. ~(C & G)                                        3, 4 Modus Tollens
  6. ~C v ~G                                         5, DeMorgan’s Theorems
  7. C → ~G                                         6, Implication
  8. A → ~G                                         2, 7 Hypothetical Syllogism
  9. ~A v ~G                                         8, Implication

[3] Well-known philosopher of religion William Rowe has developed such a scenario in his statements of the evidential argument from evil. See, for instance, his Philosophy of Religion: An Introduction, 4th Edition (Belmont, CA: Thomson/Wadsworth Publishing, 2006), p. 120.

[4] The rules of probability tell us that that individual probabilities can be quite low, but their disjunction can be very high. For instance, there may be only a small chance that you will be involved in an automobile accident on a given day, but if you drive every day, the chances are pretty good that you will be in one on some day in your lifetime. Similarly, even if the chance that a given instance of a trillion cases of suffering is gratuitous is quite low, the chance that one of that trillion is gratuitous can be can be very high, and it only takes one instance of gratuitous evil to rule out the existence of God.

[5] See John Hick, Evil and the God of Love (London, UK: Macmillan, 1966) and Richard Swinburne, The Existence of God (Oxford, UK: Clarendon Press, 1979).

[6] Alvin Plantinga, “Self Profile” in Alvin Plantinga ed. James E. Tomberlin and Peter van Inwagen (Dordrecht, Holland: D. Reidel Publishing Company, 1985), p. 35.

Copyright ©2011 Keith Parsons. The electronic version is copyright ©2011 by Internet Infidels, Inc. with the written permission of Keith Parsons. All rights reserved.

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