God, Evil, and the Possible Worlds
A Look at the Modal Problem of Evil
By:
Trey Anastasio
Philosophy 389
Dr. Jeremy Kirby
Abstract: Paul Sheehy, in his essay entitled “Theism and modal realism” argues that in order for
the theist to accept a Lewisian form of modal realism, he must make changes to the classical
conception of God. The most potent of his attacks comes in the form of a modal problem of evil.
He states that God creates a world by conceiving of it, and God must be able to conceive of an
extremely evil world, attacking God’s property of being all-benevolent. I argue that it is possible
for God not to be able to conceive of an extremely evil world, thereby resisting Sheehy’s
argument.
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The Problem of Evil
The problem of evil has been a thorn in the side of theists since theism has been around.
The problem, put simply, goes as follows:
(1) If an all-powerful and perfectly good god exists, then evil does not.
(2) There is evil in the world.
(3) Therefore, an all-powerful and perfectly good god does not exist
.
While this may seem hard enough, Lewisian modal realism, the idea that a plurality of concrete
worlds exist, throws an even larger knot into the problem. A conceivable world is a possible
world and a possible world is a real world, so the theist must now account for worlds where it is
conceivable that more evil exists than good. Although Sheehy argues that a theist who accepts
modal realism must radically change their classical conception of God, I argue that this view of
God is perfectly fine, rather it’s impossible worlds that present a problem.
Lewis’s Argument for Modal Realism
While Sheehy doesn’t argue for or against modal realism in his paper, it’s important to
understand the concept before diving into his essay. Sheehy presents a view of modal reality first
championed by David Lewis (Lewis, 162-7), who argues for the following theses:
(A) There is no primitive modality
(B) There exists a plurality of concrete worlds
(C) Actuality is an indexical concept
(D) Modality de re is to be analyzed in terms of a counterpart relation
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By asserting (A), Lewis sets up the need for an analysis of what modality is, otherwise he
will be stuck with defining necessity and possibility in their own terms, a process generally
frowned upon within philosophy. So, Lewis makes the move to say:
(LW) X and Y are world-mates iff X and Y are spatially, temporally, or spatiotemporally related.
With this definition in hand, Lewis can say that a proposition is necessarily true if and only if it
is true in every (LW) world. Furthermore, a proposition with be possibly true if and only if it is
true in some (LW) world. In this way, Lewis avoids begging the question.
Claim (B) is obviously the meat and potatoes of Lewis’s theory of modal realism. For
that reason, a cursory glance at the argument he composes to defend the claim will prove helpful.
It runs as follows:
(1) I think there are other ways the world might have been
(2) I believe the existentially quantified statement: ∃x (x is the set of other ways the world
might have been.
(3) “ways the world might have been” and “possible worlds” are taken as synonymous.
(4) So, I believe in possible worlds.
There does seem to be a question of how this can commit him to concrete worlds, not abstract
ones, but Sheehy doesn’t address this.
In making the claim (C), Lewis is saying that a world is “actual” for the people inhabiting
the aforementioned world. Actuality comes with context; for example, if someone said that the
actual world contained an honest politician (a clearly fallacious statement) they would be
wrong. On the other hand, if the inhabitant of a possible world, P, a world in which honest
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politicians resided (a remote world, indeed) said that the actual world, P, contained an honest
politician, they would be telling the truth. Actuality depends on the context of the statement.
Lewis’s final claim, (D), invokes the idea of counterparts. A counterpart, as explained by
Joseph Baltimore, is a person in another world that sufficiently resembles a person in the actual
world (Baltimore, 121). Take the counterfactual claim “if McCain had won the election, then
Obama wouldn’t be president”; in the possible world where McCain had won the election, that
McCain would be the actual McCain’s counterpart. With this account of modal realism in mind
(Lewis 162), Sheehy goes to work on the classical conception of God.
Conceivability and Possibility
First of all, Sheehy makes clear that his intent is not to disprove the existence of God
using modal realism, he merely wants to show the price a theist might have to pay if he
accepts Lewis’s version of modal realism (Sheehy, 323). The most potent attack for the
theist/modal realist comes from Sheehy’s explication of the problem of evil in light of possible
worlds. This argument has been made before (Guleserian, 221), but rather than attacking the
connection between modal realism and classical theism, the argument attacks the notion that
God’s great-making qualities are essential. Sheehy’s argument is more consistent with the
somewhat questionable status of Lewis’s modal realism. The objections made in this essay,
however, may apply to both arguments.
In order to have an account of what worlds are to be considered “real”, there must first be
an explanation of what makes a world possible, because in Lewis’s (and therefore Sheehy’s) it
is the possible world that is the real world. Conceivability seems to be a pretty good test for
showing whether or not a world is possible. For example, can someone conceive of a world
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where it is true that 2 + 2 = 5? It seems not; so that person can say that “there is no possible
world where 2 + 2 = 5”, and then “there is no real world where 2 + 2 = 5”. This line of
reasoning can be made explicit as follows:
(1) If a world, p, is conceivable, then it is possible.
(2) If a world, p, is possible, then it is real.
(3) A world with honest politicians is conceivable (barely)
(4) Therefore, a world with honest politicians is possible
(5) Therefore, a world with honest politicians is real.
There are some objections, however, to the view that conceivability automatically entails
possibility (Chalmers, 145-150). Sheehy even attacks the notion that possibility means reality,
stating “the question of whether some state, s, is possible or not is a metaphysical issue, which
we have no reason to expect to be settled by our conceptual or imaginative faculties but by the
nature and limits of reality.”(Sheehy, 322) Since, however, Sheehy is taking up the Lewisian
project, this objection can be shelved for the time being.
Sheehy’s Modal Problem of Evil
Using the conceivability argument as his test for the possibility of a world (Sheehy, 321),
Sheehy posits that a world, x, filled with suffering much greater than suffering found in the
actual world certainly seems conceivable. From there it follows that this world, x, is possible,
and therefore real under the Lewisian view of modal realism. Here is where the dilemma
occurs: a theist must maintain the assumption that God (an omnipotent, omniscient, allbenevolent creature) created such a world (Sheehy, 321) x, even though this completely
undermines the classical conception of God as a necessarily all-benevolent creature. Perhaps
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the theist may maintain that there aren’t any worlds of terrible suffering such as x. It seems
possible, for example, that all possible worlds have at least some minimal level of good in
them. Furthermore, it also seems possible that, in every possible world, a cap is put on the
amount of evil allowed. Sheehy responds to this criticism by asking, if a world of terrible
suffering much greater than our own isn’t really possible, why then is it so easy to conceive
(Sheehy, 322)? Be reminded, conceivability entails possibility, and a possible world is a real
world.
Raising another objection to his own project, Sheehy asks if it is conceivability and
possibility can be separated so that the theist need not deal with evil worlds. Take the claim:
(W) An extremely evil world (A world where evil outweighs or is equal to good) is possible
Such a world certainly seems possible, but its possibility relies on the assumption that an allbenevolent God does not exist; such a God would not allow this world to exist. Perhaps the
theist simply needs to “concede...a standoff with respect to intuition concerning the divine and
the range of possible worlds (Sheehy, 323).
Sheehy does, however, offer a response to this standoff. His assumption involves how
God creates worlds. In his view, this comes about by divine intellection; in laymen’s terms,
God creates worlds by conceiving them (Sheehy, 323). His argument from there may be
fleshed out in the following way:
(1) Anything a human being can conceive of, an omnipotent being can conceive of
(2) A human being can conceive of an extremely evil world
(3) Therefore, an omnipotent being can conceive of an extremely evil world
(4) God is an omnipotent being
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(5) Therefore, God can conceive of an extremely evil world
Perhaps, however, the theist may make the move to say that evil worlds, as Sheehy has
been describing them, aren’t possible at all. That is to say, when someone conceives of a “truly
evil world” they are really thinking about something different altogether. Doesn’t it seem
though, that it is possible to truly conceive of an evil world? Unless a person happens to be
delusional or mentally incapable, a truly evil world certainly seems to be conceivable to most
people. The theist must, if they are to make this move, provide a reason why a person can have
an “impossible thought”. As Sheehy puts it “I can only conceive of that which is possible. A
commitment to the classical conception of God requires us to abandon our considered and
reasonable judgments concerning possible states….My belief was a ‘mock’ belief and the theist
owes an account of how I can come to have impossible thoughts and of how one should
analyse the content of such thoughts.”(Sheehy, 323-4) In this way, Sheehy feels as though he
has shown modal realism (at least in its Lewisian form) to be incompatible with the classical
conception of God. While at first glance Sheehy’s version of the modal problem of evil might
seem like a knock down argument for the theist who accepts modal realism, several objections
can show that the theist/modal realist is in fact not obligated to give up as much as Sheehy
would like to prove.
Objections
A common criticism was mentioned at the beginning of this essay but it bears mentioning
again here. The theist may likely want to weaken the link between conceivability and possibility.
Should our epistemic faculties really have the final say over what makes things possible and
therefore real, which is after all a metaphysical issue? The theist may follow in the foots of Paul
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Tidman, who wrote “Our ability to conceive of wretched worlds…..does not give us reason to
think them possible, especially since we can equally well conceive of the possibility that God
necessarily prevents such worlds from obtaining.” (Tidman, 193) Sheehy may be able to avoid
this critique by pointing out that he is simply adopting the Lewisian framework for modal
realism, not advocating for it. After saying that, he can continue on with the assumption that
conceivability does entail possibility, as mentioned earlier.
Sheehy isn’t exactly off the hook yet. While it seems correct that there must be a standoff
between, as Sheehy puts it, “intuitions concerning the divine nature and range of possible
worlds”, (Sheehy, 323) his reply to this issue does not seem convincing. Take Sheehy’s
argument for God’s ability to conceive of evil worlds:
(1) Anything a human being can conceive of, an omnipotent being can conceive of
(2) A human being can conceive of an extremely evil world
(3) Therefore, an omnipotent being can conceive of an extremely evil world
(4) God is an omnipotent being
(5) Therefore, God can conceive of an extremely evil world
This seems to prove that God, an omnipotent being, has the power to conceive of extremely evil
worlds. The theist may respond, however, that God need not conceive of those worlds in order to
preserve his omnipotence. For example, it may be within someone’s power to punch Zac (a good
friend of mine) straight in the face. Never would it be said, however, that to refrain from
punching Zac means to lose the power to do so. The same case can be made for God: while it
certainly is possible for God to conceive of an extremely evil world, certainly it’s not the case
that he must conceive of the aforementioned world in order to retain his property of
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omnipotence. This objection allows the theist to maintain God’s omnipotence, his own ability to
conceive of extremely evil worlds without issuing in the unwelcome consequence that God
actually creates those worlds.
Sheehy may make a reply against the omniscience of God. If God is truly omniscient, he
might say, then God would have to be in some sense conceiving of all possible worlds at all
times. While God not conceiving of a possible world may protect his omnipotence, it remains the
case that a God who is omniscient would be conceiving of all possible states of affairs. Since the
theist has admitted that an extremely evil world is indeed possible, God’s omniscience must
commit him to conceive of such a world. This objection again leaves the theist again to explain
how God could conceive of (and therefore create) such an evil world.
Perhaps, though, the theist may be able to wriggle out of evil’s cold grip by maintaining
that God can actually not conceive of an extremely evil world. In that case, the theist must attack
(1) of Sheehy’s ‘argument for God’s conception’, while still maintaining the classical conception
of God, namely his omnipotence. This may appear to be a startling task at first, but it can be
made quite easily through an analogy. Humans have the ability to commit evil acts. One can
imagine a world where Zac gets beaten senseless by an angry philosophical opponent. There is
no doubt that most people would agree that this is a heinous, evil act. But can Sheehy really
make the claim that God has the ability to commit evil? A general intuition about the subject
appears to indicate that God cannot, in fact commit an evil act. Would that be a way to take away
from the omnipotence of God? It certainly doesn’t appear so. In the same way, a theist may make
the claim that humans have the capacity to conceive of extremely evil worlds, but (in a way
analogous to God’s inability to sin) God cannot conceive of those worlds and therefore does not
create them. With that claim in mind the theist needs to deal only with evil in this world (and all
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possible worlds where good outweighs evil), not any conceivable world. This is where
theologians may come in with their theodicies. Sheehy may reply that the actual world is one
where evil outweighs good, but this statement seems almost impossible to prove. While Sheehy
may also reply that the theist has ruled out too many worlds, the theist can make the claim that
giving up possible worlds is much less problematic than giving up the classical conception of
God, as Sheehy proposes.
Conclusion
Paul Sheehy has attempted to show that in order for a theist to accept a Lewisian model
of modal realism, he must first change some of the qualities normally ascribed to God. He
attempts to show that an extremely evil world, a world where evil outweighs good, is
conceivable and therefore real. This ‘real world’ provides an attack on God’s benevolence,
Sheehy claims, because it is only in God conceiving a world that the aforementioned world is
created. Also, he goes on to claim that any attempt to show that God cannot conceive of such a
world is an attack on God’s omnipotence. In response to this claim, I show that just as God
cannot commit evil acts, God cannot conceive of extremely evil world. Since, by Sheehy’s own
claim that it is only in God conceiving of a world that it is real, the theist can claim no extremely
evil world is real, thereby resisting Sheehy’s modal problem of evil.
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Works Cited
Baltimore, Joseph A. "Lewis’ Modal Realism and Absence Causation." Metaphysica 12.2
(2011): 117-24. Print.
Chalmers, D. J. "Does Conceivability Entail Possibility?" Conceivability and Possibility. Ed. T.
S. Gendler and J. Hawthorne. Oxford UP, 2002. 145-200. Print.
"Does Conceivability Entail Possibility." Web.
Guleserian, T. "God and Possible Worlds: The Modal Problem of Evil." Noûs 17.2 (1983): 22138. JSTOR. Web.
Louis, David. "Possible Worlds." Metaphysics: Contemporary Readings. By Michael J. Loux.
London: Routledge, 2001. 160-67. Print.
Sheehy, Paul. "Theism and Modal Realism." Religious Studies 42.03 (2006): 315. JSTOR. Web.
Tidman, P. "The Epistemology of Evil Possibilities." Faith and Philosophy 10.2 (1993): 181-97.
JSTOR. Web.