The Problem of Evil

Author: Thomas Metcalf
Category: Philosophy of Religion
Word Count: 1000

Many people believe in God and understand God to be an omnipotent (all-powerful), omniscient (all-knowing), and morally perfect being.[1]

But the world contains quite a lot of evil or badness: intense suffering, premature death, and moral wickedness.

This inspires some questions: Why would God permit such evil? Is there a good reason why? Or does it occur in part because there is no God to prevent it?

Asking these questions involves engaging with the Problem of Evil.[2]

The concern is whether evil provides a reason to disbelieve in God. There are four things one might say about evil, ranging from that it proves that God does not exist to that it provides no evidence at all against God’s existence.


1. The Incompatibility Problem of Evil

The ‘Incompatibility’ or ‘Logical’ versions of the Problem of Evil claim that evil’s existence is logically incompatible with God’s existence: believing in God and evil is like believing in a five-sided square, a contradiction.[3]

Most philosophers today reject this argument.[4] They think that God could have some sufficient reason to permit some evil: e.g., personal growth requires confronting challenges that inherently involve some evil or bad things. These defenses[5] seem to show that it is not contradictory to believe in God and the existence of evil.

2. The Evidential Problem of Evil

Other philosophers argue that the mere existence of evil does not prove that God does not exist, but that the facts about evil provide good evidence against God’s existence.[6]

There are probably billions of evils such that we do not know why God, if there is a God, would permit them. Many argue that if even one of these instances is gratuitous—i.e., God could have prevented it without thereby sacrificing an equal or greater good and without thereby permitting an equal or worse evil—then God does not exist.[7]

Theists have reason to find an explanation or set of explanations that could plausibly justify all evils. This involves trying to find plausible theodicies or explanations of why God would permit that evil or why that evil is not as evidentially weighty as it might seem. Here’s a summary of two of the best theodicies.

2.1. Free Will

Many theists hold that humans’ having significant free will is a very great good, one that is worth the evil that sometimes arises from it.[8]

This being a plausible explanation of evil depends on justifying these claims:

(a) we have libertarian free will[9] (a belief that is mostly rejected by philosophers[10]);

(b) (e.g.) Stalin’s free will was more valuable than the lives of the millions he killed (against, presumably, their freely-willed choices to remain alive);

(c) God must let us have not only our decisions but also the effects that result from them[11]; and

(d) even apparently natural disasters and disease, including those that harm nonhuman animals[12], are all the result (e.g.) of free-willed evil-spirits’ choices.[13]

2.2. “Soul-Making”

Perhaps encountering evil and freely responding to it develops various virtues, such as compassion, generosity, and courage.[14]

For this to explain evil, the theist may need to argue that:

(a) God could not have developed those virtues in us any other equally valuable but less harmful ways (e.g,. by creating humans who are more morally sensitive in the first place and reducing evil accordingly);

(b) all evil can reasonably be expected to contribute to soul-making; and

(c) the compassion Smith develops when she sees Jones suffering justifies God using Jones (or allowing Jones to be used) as a means to the end of producing that compassion.[15]

Given these and other theodicies, we must ask how much evidence evil provides, and weigh that against any evidence for God’s existence. This will obviously be very complicated.

3. Outweighing Evidence?

Theists might argue that there is so much evidence for God’s existence that we are justified in being confident that God has a purpose for all evil.[16]

We cannot consider those arguments here, but we should recall how many billions of instances of severe, inscrutable evils there are in the world. Therefore, for this defense to work, perhaps there must be very strong evidence for God’s existence. Also, a substantial majority of philosophers reject theism,[17] and so seem to believe that there is little good evidence for God’s existence. Therefore, this strategy may depend on appealing to a set of generally-rejected arguments to try to explain evil.

4. Evil Is No Evidence?

Some defenses amount to the response that evil is no evidence against God’s existence at all.

Some argue that we should not expect to understand why God would permit evil, and so we should not be confident in our ability to assess whether some evil is gratuitous.[18] If there is a God, God might have a purpose for all the evil in the world, a purpose that we do not or cannot understand, and so we should not trust our doubt that some evil in the world is justified.[19]

Typically, this inspires the question of whether a similar argument can be made about other beliefs we have, thereby threatening to produce a deep, general skepticism about science, morality, and even arguments for God’s existence.[20] If God works in mysterious ways, how do I assess the likelihood that God has some inscrutable reason for tricking me into (wrongly) thinking that other minds exist, that the past exists, that an external world exists, and that I ought to save a child drowning in a shallow pond? This is perhaps the primary focus of the debate about the Problem of Evil in recent years.

Finally, some philosophers argue that God’s existence is actually compatible with gratuitous evil after all,[21] although most philosophers disagree.[22]

5. Conclusion

If each particular evil is even a little bit of evidence against God’s existence, the billions and billions of them in history might really pile up. For many people, the problem of evil is not merely an abstract puzzle, for it challenges their most profound beliefs about what God is like and whether God even exists.


[1] Anselm 1965 [1077-78]: ch. 2.

[2] The Problem of Evil involves engaging arguments from the existence of evil, or types of evils, to the conclusion that God does not exist. So the Problem of Evil is also called The Argument from Evil.

[3] Mackie 1955. “Evidential” versions of the argument, discussed in the next section, typically focus on the totality of evil and can be seen as “Incompatibility” arguments also: the claim is that God’s existence entails that there are no gratuitous or pointless evils—evils God could have prevented it without thereby sacrificing an equal or greater good and without thereby permitting an equal or worse evil—but that there are such gratuitous or pointless evils, which is a logical contradiction.

[4] Rowe 1979: 335.

[5] A “defense” is an attempt to explain why God and evil are not incompatible. Defenses are closely related to theodicies (two of which are presented below) which attempt to explain why God permits evil. Defenses and theodicies are different: defenses hold that there is some possible explanation, even if we’re not sure what it is, while theodicies attempt to supply that actual explanation.

[6] Rowe 1979; Draper 1989; Tooley 2014: § 3.2.1.

[7] Howard-Snyder and Howard-Snyder 1999.

[8] Plantinga 1977: 29-59.

[9] For an explanation of what libertarian free will is, see Jonah Nagashima’s Free Will and Free Choice. Libertarians about free will (a view of which has no relation to the political position of the same name) believe that free choices are choices that are not causally determined by the past and the laws of nature (or anything else), and so they believe that determinism is false, yet that such choices are not ultimately random because we are the ultimate source of our choices.

The other broad definition of free will is that of compatibilist free will. On this theory of free will, we can be determined to do what we do, yet our actions can still be done from free will if, e.g., we are doing what we want to do and acting on our own desires. This view of free will seems to allow that God could cause us to not act in horribly evil ways, and that we freely choose to never engage in these evils, and so the free will defense is not available to compatibilists.

[10] Bourget and Chalmers 2014.

[11] So, e.g., Stalin might freely make the choice to kill someone, but whether the effect of that choice—that is, whether someone is actually killed—seems to be another matter. So, a question is whether, if there is a God, God could allow us to freely make decisions (which is assumed to be a great good), but prevent the very bad effects that result from some of them, and God be justified preventing those very bad effects. 

[12] Rowe 1979: 337.

[13] Plantinga 1977: 58.

[14] Hick 2007: 253-61.

[15] cf. Kant 1987 [1785]: 4:429; Trakakis 2008.

[16] cf. Rowe 1979: 338.

[17] Bourget and Chalmers 2014.

[18] Howard-Snyder and Howard-Snyder 1999: 115.

[19] Wykstra 1998.

[20] Draper 1998: 188; Russell 1998: 196-98. The general response to the Problem of Evil that we are not likely to know whether any evil is gratuitous or pointless is known as “Skeptical Theism,” since skeptics deny that we have a type of knowledge. A concern about skeptical theism is whether the motivations for it lead to or justify other types of skepticism.

[21] van Inwagen 2000; Kraay 2010. van Inwagen’s argument is complex and depends on the (controversial) claim that it can be permissible to allow some unjustified evils, e.g., that it could be permissible to allow someone to remain imprisoned for at least slightly longer than any just imprisonment because sometimes arbitrary lines must be drawn. From there, he appeals to something like a “little by little” argument (based on concerns about vagueness: see Darren Hibb’s Vagueness). that if a little unjustified evil can be permissibly allowed, then a tiny bit more can be permissibly allowed, so then a little more can be allowed, leading to the conclusion that any unjustified evils can be allowed.

[22] Howard-Snyder and Howard-Snyder 1999; Trakakis 2003.


Anselm. (1965 [1077-78]). St. Anselm’s Proslogion. Tr. M. J. Charlesworth. Notre Dame: University of Notre Dame Press.

Bourget, David and David J. Chalmers. (2014). “What Do Philosophers Believe?” Philosophical Studies, forthcoming.

Draper, Paul. (1989). “Pain and Pleasure: An Evidential Problem for Theists.” Noûs 23: 331-50.

———. (1998). “The Skeptical Theist.” In Daniel Howard-Snyder (ed.), The Evidential Argument from Evil. Bloomington and Indianapolis: Indiana University Press, 175-92.

Hick, John. (2007). Evil and the God of Love. New York: Palgrave Macmillan.

Howard-Snyder, Daniel and Frances Howard-Snyder. (1999). “Is Theism Compatible with Gratuitous Evil?” American Philosophical Quarterly 36 (2): 115-30.

Kant, Immanuel. Groundwork of the Metaphysics of Morals. In Kant, Immanuel. Practical Philosophy. Ed. Mary J. Gregor. Cambridge, U.K.: Cambridge UP, 1999.

Kraay, Klaas J. “Theism, Possible Worlds, and the Multiverse.” Philosophical Studies 147 (2010), pp. 255-68.

Mackie, J. L. (1955). “Evil and Omnipotence.” Mind 64 (254): 200-12.

Plantinga, Alvin. (1977). God, Freedom, and Evil. Grand Rapids, MI: Wm. B. Eerdmans.

Rowe, William. (1979). “The Problem of Evil and Some Varieties of Atheism.” American Philosophical Quarterly 16(4): 335-41.

Russell, Bruce. (1998). “Defenseless.” In Daniel Howard-Snyder (ed.), The Evidential Argument from Evil. Bloomington and Indianapolis: Indiana University Press: 193-205.

Tooley, Michael. (2014). “The Problem of Evil.” In Edward N. Zalta (ed.), The Stanford Encyclopedia of Philosophy (Spring 2014 edition), URL = <>.

Trakakis, Nick. (2008). “Theodicy: The Solution to the Problem of Evil, or Part of the Problem?” Sophia 47: 161-91.

———. (2003). “God, Gratuitous Evil, and van Inwagen’s Attempt to Reconcile the Two.” Ars Disputandi 3 (1): 1-10.

van Inwagen, Peter. (2000). “The Argument from Particular Horrendous Evils.” Proceedings of the American Catholic Philosophical Association 74: 65–80.

Wykstra, Stephen John. (1998). “Rowe’s Noseeum Argument from Evil.” In Daniel Howard-Snyder (ed.), The Evidential Argument from Evil. Bloomington and Indianapolis: Indiana University Press: 126-50.

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Revision History

This essay, posted 8/16/2020, is a revised version of an essay originally posted 4/7/2014.

About the Author

Tom Metcalf is an associate professor at Spring Hill College in Mobile, AL. He received his PhD in philosophy from the University of Colorado, Boulder. He specializes in ethics, metaethics, epistemology, and the philosophy of religion. Tom has two cats whose names are Hesperus and Phosphorus.

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