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Quadrivium Issue 6


The Logical Problem of Evil and the Limited God Defense

By Darren Hibbs

The philosophical problem of evil can be formulated in two ways 2.  Each formulation presents an argument against the existence of God.  One version of the problem is the “Logical Problem of Evil” (LPE hereafter).  The LPE is a deductive argument.  A deductive argument is an attempt to prove that a conclusion is necessarily true, given the evidence.  The LPE can be expressed as follows:

  1. If God exists, then evil would not occur.
  2. Evil occurs.
  3. Therefore, God does not exist.

The second version of the problem is the “Evidential Problem of Evil” (EPE hereafter).  The EPE is an inductive argument.  Inductive arguments attempt to prove that a conclusion is probably true, given the evidence.  The EPE can be expressed by modifying statements 1 and 3 of the LPE:

  1. If God exists, then evil would probably not occur.
  2. Evil occurs.
  3. Therefore, God probably does not exist.

The task for those who reject the LPE and the EPE arguments is to explain why these arguments fail.  My aim is to briefly discuss a response to the LPE called the “Limited God Defense” (LGD hereafter).  The LGD has not been a popular response to the LPE.  I will explain one objection to the LGD and then argue that the objection is not persuasive.  I will begin by elaborating some of the details of what I take to be the strongest version of the LPE.

Since the LPE is a deductive argument, it is an attempt to establish that it is impossible for its conclusion to be false, given the evidence offered in support of the conclusion.  The evaluation of a deductive argument is a two-step process.  The first step is to determine whether the argument is valid.  A deductive argument is valid if and only if it is impossible for the conclusion to be false, given the assumption that all the premises are true.  The premises of an argument comprise the evidence presented in support of the conclusion.  In the LPE above, the premises are propositions 1 and 2.  If we assume that both premises are true, then the conclusion must be true as well.  Validity is a property related to the form of an argument.  The form of the LPE argument above can be expressed by using symbols in place of the individual statements in the following manner:

  1. If X, then not-Y.
  2. Y.
  3. Therefore, not-X.3

This argument relies on the claim that X and Y are logically incompatible.  If we assume that it is true that X and Y are logically incompatible, that means X and Y cannot be simultaneously true, although they may be simultaneously false.  Thus, if X is true, then Y must be false, and vice versa.  The second premise in the argument asserts that Y is true, therefore it follows that X must be false 4.

However, the fact that a deductive argument is valid does not guarantee that the argument is a comprehensive success.  The second step in the process of evaluation is to determine whether the argument is sound.  A valid deductive argument is sound if and only if all the premises are true.  The test for validity involves the assumption that all the premises are true.  Soundness requires that every premise be true not by assumption, but in fact.  The two premises are about “God” and “evil”.  In order to determine whether these premises are true, one would have to understand what is meant by those terms and what each statement is asserting about them.  The LPE argument relies on a particular notion of God that is grounded in western philosophical and theological traditions that I will call the “traditional” concept of God 5.  According to the traditional notion, God is a personal deity that created the universe, governs the universe, and possesses the properties of omniscience, omnipotence, and moral perfection.  If God is omniscient, God knows the truth value of every proposition.  If God is omnipotent, God can do anything that is possible.  If God is morally perfect, God is morally infallible in terms of thought and action 6.  Given this definition of God, the reasoning in support of premise 1 is as follows.  Since God is omniscient, God is aware of every occurrence of evil.  Since God is omnipotent, God could prevent any instance of evil.  Since God is morally perfect, God would want to prevent evil.  Thus, if God exists, then evil would not occur.

 The term “evil” is used in the present context to refer to suffering.  Suffering includes all the unpleasant experiences that sentient beings might endure, including physical pain and psychological pain.  Suffering can be brought about in different ways.  Some suffering is caused by human agency.  Murders, assaults, and other more trivial activities that human beings choose to engage in cause suffering.  Suffering that results from human agency is typically called “moral evil.”  Suffering is also caused by “natural” events.  The content and structure of the universe, along with the laws that govern it, produce diseases, famine, earthquakes, storms, floods, and other disasters that cause suffering 7.  Suffering of this sort is typically called “natural evil.”

The LPE may rely on the claim that the occurrence of suffering in general is incompatible with the existence of God or it may be modified to refer to some, but not all, suffering.  This is due to the possibility that some suffering may be deserved or that some cases of suffering are necessary to bring about something good that would otherwise not be realized.  For example, some suitable level of suffering might be morally permissible as a form of punishment for a person who violently attacks another person without justification.  In other cases it may be necessary to cause pain to bring about something good.  Some legitimate medical procedures cause pain, but the procedure may be required to produce something good that would otherwise not be realized (e.g. long term relief from a painful disorder).  Given these possibilities, God might be justified in allowing some suffering 8.  Taking this into account, a modified LPE argument would target unnecessary, or gratuitous, suffering.

  1. If God exists, then gratuitous suffering would not occur.
  2. Gratuitous suffering occurs.
  3. Therefore, God does not exist.

Suffering that is gratuitous or “pointless” is the sort of suffering that could have been prevented by God without thereby losing something good.  The modified version of the LPE has the same form as the original, so it is valid.  It is the strongest version of the LPE in my view since it selects the most puzzling occurrences of suffering (within a traditional theistic framework) as the basis for challenging theism.  The soundness of this version of the LPE will therefore depend on whether or not gratuitous suffering occurs and, if so, whether or not its occurrence is logically incompatible with the existence of God.
LPE advocates offer alleged examples of gratuitous suffering to support premise 2.  The following is a candidate for gratuitous moral evil:
A man kidnaps, brutally beats, rapes, and then strangles a five year old child to death.
Here is a candidate for gratuitous suffering that is an instance of natural evil:
In some distant forest lightning strikes a dead tree, resulting in a forest fire. In the fire a fawn is trapped, horribly burned, and lies in terrible agony for several days before death relieves its suffering 9.

LPE partisans argue that similar events occur frequently, and since an ordinary, decent human being would prevent them if they could, the fact that nothing prevents them entails that a morally perfect, all powerful deity doesn’t exist.

Critics employ several strategies in response to the LPE that I will not explore 10.  My aim is to discuss one aspect of a defensive strategy that avoids the logical problem by introducing the notion of a limited God. The LGD can be constructed in different ways.  The version I will focus on amounts to the view that God is neither omniscient nor omnipotent in the traditional sense of the terms 11.  If this is the case, then it is obvious that the existence of such a being is at least logically compatible with the occurrence of gratuitous suffering.  For any given case of suffering, it is logically possible that a limited God may not know about it, since God is not omniscient.  For any given case of suffering, it is logically possible that God may not be able to prevent it, since God is not omnipotent.  If God is limited in these ways, premise 1 of the LPE is false and the argument is therefore unsound.  Although this seems like an obvious strategy to defuse the LPE, the LGD has not been a popular response.  Why?

The prevailing view among philosophers who respond to the LPE challenge is to retain the traditional notion of a perfect God and explain how the existence of such a being is compatible with the suffering that occurs 12.  The importance of retaining the notion of a perfect God is grounded in metaphysical and religious concerns 13.  One metaphysical concern is related to the “Ontological Argument” for the existence of God 14.  Arguments for the existence of God are usually divided into two categories: a posteriori and a priori arguments.  A posteriori arguments rely upon evidence derived from experience.  For example, the “Teleological Argument” appeals to the observation that nature seems to be similar to artifacts in the sense that both nature and artifacts appear to be “designed” for some purpose or end.  Since artifacts are products of intelligent design, then, by analogy, the universe is also the product of intelligent design.  A prioriarguments rely solely upon an analysis of concepts rather than appealing to observable features of the universe.  The “Ontological Argument” is an example of an a priori argument for the existence of God.  Ontology is a branch of metaphysics that is concerned with fundamental questions about the nature of existence or being.  The Ontological Argument was first formulated by St. Anselm and has subsequently been restructured in numerous ways 15. The crucial claim in the Ontological Argument is that “existence” is an essential property of a perfect God’s nature in the same way that omniscience, omnipotence, and moral perfection are essential parts of a perfect God’s nature.  A simple example of how a property can be essential to the nature of something is to consider the concept of a triangle.  The property “having three sides” is an essential part of what it means to be a triangle.  The Ontological Argument maintains that the property “existence” is to the nature of God as the property “having three sides” is to the nature of a triangle.  A simple version of the argument can be expressed as follows:

  1. By definition, God is a perfect being.
  2. A perfect being does not lack any perfection.
  3. Existence is a perfection.
  4. Therefore, a perfect being (God) must exist by definition.     

The upshot is that a proper analysis of the concept of a perfect being reveals that such a being must possess the property of existence.  Proponents of the argument also claim that the properties of omniscience, omnipotence, and moral perfection are also necessary components of a perfect deity’s nature 16.

Divine perfection, traditionally understood, plays a central role in the version of the Ontological Argument above.  However, a version of the argument can be constructed that does not require an appeal to perfection, at least as perfection is understood in the traditional sense. The argument employs “modal” language17.  In the present context, modal claims are about the types of existence an entity can have.  The modal status of an entity might be “possible”, “impossible”, or “necessary.”  The meaning of these terms in modal discourse is often explained by appealing to the concept of a “possible world.”  The actual world is a possible world, but things could have been different (or so it seems).  For example, it is possible that the number of states that comprise the United States could currently be 49.  In modal discourse, this means there is a possible world (distinct from the actual world) where the number of states is 49.  Other possible worlds are more radically different than the actual world.  There are as many possible worlds as there are possible states of affairs that could constitute a world.  The concept of a possible world can be used to explain how “possible,” “impossible,” and “necessary” specify the modal status of different kinds of entities.  A possible being is one that exists in at least one possible world.  That is, it exists only in those worlds where the conditions necessary for its existence obtain. An entity such as a mountain is possible in this sense because it exists due to the presence of certain geological conditions.  Some possible worlds do not contain the conditions for the existence of mountains, so mountains and other “merely possible” entities do not exist in every possible world.  An impossible entity is one that does not exist in any possible world.  An entity is impossible if its properties are “logically incompatible.”  Properties are logically incompatible if they cannot coexist in the same object.  An example of an impossible entity is that of a plane figure that is a “three-sided square.”  Three-sided squares cannot exist in any possible world because having three sides is incompatible with being square.  Finally, a necessary being is one that exists in every possible world.  That is, its existence is unconditional (unlike a mountain), it has no origin, and it cannot fail to exist.  This sounds reminiscent of the characterization of God in the original ontological argument above since it makes the same claim that existence is essential to the nature of this sort of being.  However, a modal version of the Ontological Argument can be formulated that makes no appeal to perfection as including omniscience and omnipotence.  A modal version of the argument is as follows:

  1. A being is possible if its concept is logically coherent.
  2. The concept of a necessary being is logically coherent.
  3. Hence, a necessary being is possible.
  4. If a necessary being is possible, then it necessarily exists.
  5. Therefore, a necessary being exists.

The modal argument asserts that the concept of a necessary being isn’t incoherent in the way that a three-sided square is incoherent.  That is, there is no reason to think that an independent, eternally existing being is logically impossible based on an inspection of the concept of such a being.  Premise 4 asserts that if a necessary being is possible, then it must exist.  The assumption underlying this premise is that it is impossible for a necessary being to exist in some, but not all possible worlds.  If premise 3 is true, then a necessary being exists in at least one possible world.  But if an entity exists in some, but not all, possible worlds, it is not a necessary being by definition (i.e. it would be merely possible). Therefore, if a necessary being is logically coherent, it must exist in all possible worlds and that includes the actual world.

Other than necessary existence, what sorts of properties could such a being possess?  Any properties that are logically compatible with necessary existence are candidates.  The selection of additional properties may be more or less defensible based on one’s theoretical goals or how plausible the existence of such a being is given how the world is, among other concerns.  For example, the proponents of the traditionalist notion of God would argue for including omniscience, omnipotence, and moral perfection to complete the concept of a necessary being.  However, the traditionalist account introduces the LPE as a challenge to the existence of such a being.  The LGD neutralizes the LPE if the necessary being is construed as a limited God that lacks omniscience and omnipotence.  For example, instead of omniscience, a limited God may know everything about the past and the present, but does not know the truth-value of all propositions about the future.  God may see the future as a set of possibilities with some states of affairs being more probable than others.  Regarding omnipotence, God may be able to exert some measure of influence on all future events in the world, but may not be able to fully determine or control every aspect of the results.  This sort of being amounts to a limited God when compared to the traditional theist’s account where God is absolutely perfect with respect to knowledge and power 18.  The basic point is that the concept of a limited God is consistent with the reasoning of the modal ontological argument and the existence of such a being is logically compatible with gratuitous suffering.

For theists, the LPE presents a challenge because the argument is valid.  In order to defeat the argument, one would have to show that at least one of the premises is false.  Maintaining the notion of a maximally perfect being makes this challenge difficult.  The LGD is the most straightforward way of showing that the LPE is unsound, since the existence of a limited God is logically compatible with gratuitous suffering.  But many theists have been reluctant to employ this strategy.  One reason is that it would entail abandoning a traditional argument for the existence of God (the Ontological argument).  I have tried to show that embracing the concept of a limited God defuses the LPE but does not in-itself entail the abandonment of the ontological, or a priori, argumentative strategy for the existence of God.


1. Throughout this paper, concepts, issues, and problems that are interesting and controversial in their own right will be mentioned that will not be discussed in any detail.  First rate summaries and bibliographical information about any aspect of this problem (and most other philosophical topics) can be accessed online for free via The Stanford Encyclopedia of Philosophy at the following address <>

2. The problem of evil as I will discuss it is associated with philosophical debates generated within western monotheistic traditions. Some authors prefer to eliminate the use of the term evil.  Those who adopt this view call the problem under discussion “The Problem of Suffering”.  See Cole, Phillip, The Myth of Evil: Demonizing the Enemy. (Praeger, 2006).

3. The symbols stand for statements in the original version:  “X” = “God exists”; “Y” = “evil occurs”.

4. Another way to understand the argument is in terms of necessary conditions.  “Not-Y” being true is a necessary condition for “X” being true.  Since “Not-Y” is not the case (per premise 2), then “X” is false.  Compare with the reasoning in this example:  “X is a mammal” is a necessary condition for “X is a dog”; i.e. X cannot be dog if X is not a mammal. If the necessary condition is false (i.e. if X is not a mammal) then “X is a dog” is false also.  This argument form is called Modus Tollens.  It is a standard example of validity in classical sentential logic.  Like other traditional examples of valid argument forms, it has been challenged with counterexamples. For a counterexample to Modus Tollens, see Yalsin, Seth, Journal of Philosophical Logic, 41, (2012), pp.1001–102.

5. An influential statement of this position is in Anselm, St., Proslogion, in St. Anselm's Proslogion, M. Charlesworth (ed.). (Oxford University Press, 1965).

6. Some authors argue that this notion of God is incoherent.  See Morriston, Wes, “Omnipotence and Necessary Moral Perfection: Are They Compatible?”, Religious Studies, 37, (2001) pp. 143–160.

7. Some diseases and some natural disasters are brought about as a result of human agency.  “Naturally caused” refers to those events that are not the result of human choice.

8. Some philosophers in the Neoplatonic tradition hold evil to be non-existent, an illusion, or merely the absence or privation of the good.  I will not explore this branch of the debate either.  For a Neoplatonist account of evil as “not real”, see Plotinus, The Enneads, translated by Stephen Mackenna, (Penguin, 1991), pp. 56-70.

9. An example discussed in Rowe, William L., “The Problem of Evil and Some Varieties of Atheism,”American Philosophical Quarterly, volume 16 (1979), p. 337.

10. One popular strategy that is available to the theist is to argue that no occurrence of suffering that is a result of human agency is a case of gratuitous suffering.  This argument is called the argument from free will. There are numerous accounts of what “free will” means and how it is applied within the debate about evil.  For accounts of free will , see O'Connor, Timothy, "Free Will",The Stanford Encyclopedia of Philosophy (Spring 2013 Edition), Edward N. Zalta (ed.), URL = <>. For the “free will defense”, see Tooley, Michael, "The Problem of Evil", The Stanford Encyclopedia of Philosophy (Summer 2013 Edition), Edward N. Zalta (ed.), URL = <>.

11. I leave out a deficiency in moral character since the debate about the relationship between omnipotence, omniscience, and moral perfection is complex.  It may or may not be the case that possessing the latter property is impossible without possessing the former two properties.  This is yet another issue that I will not discuss.  For opposing views see Swinburne, Richard, Providence and the Problem of Evil. (Oxford University Press, 1998); Martin, Michael, Atheism: A Philosophical Justification, (Temple University Press, 1992).

12. Influential works that defend this view include: Adams, Marilyn McCord, Horrendous Evils and the Goodness of God, (Cornell University Press, 1999); Hick, John, Evil and the God of Love, (Harper and Row, 1978); Plantinga, Alvin, God, Freedom, and Evil. (Harper and Row, 1974); Swinburne, Richard, The Existence of God, (Clarendon Press, 1979).

13. There are many topics in each category that I will not discuss.  See Hill, David J., Divinity and Maximal Greatness, (Routledge, 2005).

14. I do not intend to argue for the soundness of any version of the Ontological Argument – only that omniscience and omnipotence are not necessary components of such an argument.

15. My discussion of the argument will remain at a very basic level.  For Anselm’s version, see note 5.  For subsequent formulations of the argument, see Oppy, Graham, "Ontological Arguments",The Stanford Encyclopedia of Philosophy (Winter 2012 Edition), Edward N. Zalta (ed.), URL = <>.

16. For an overview of criticisms of the argument, see note 13.

17. The proper analysis and usage of modal concepts is controversial.  My account is very basic and ignores technical issues.  For a detailed account of modal terminology, see Gendler, T. S. and Hawthorne, J. (eds), Conceivability and Possibility, (Clarendon Press, 2002).

18. For a similar account of God’s properties, see Hartshorne, Charles, Omnipotence and Other Theological Mistakes, (SUNY Press, 1984).

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