Is Omnipotence Logically Impossible?
by Bill Ramey
A common argument against theism runs like this:
1. If God is omnipotent, then He can do anything.The argument poses a dilemma and suggests that there is no way out, except by limiting God's power. The key premises are 1, 2, and 4. The first premise defines omnipotence as the ability to do anything. I will say more about this definition shortly, but for now, its key difficulty is its vagueness.
2. Therefore, God can create a rock so heavy that He cannot lift it.
3. But if He cannot lift it, then He is not omnipotent (because that is one thing He cannot do).
4. And If He cannot create such a rock, then He is likewise not omnipotent.
5. Therefore, God cannot be omnipotent.
The second premise is the argument's main problem. It asks us to pit God's omnipotent ability to create rocks against His omnipotent ability to lift rocks. But no matter how heavy a rock God makes, God has the ability to lift. If God makes a 2-ton rock, God can lift a 2-ton rock. If God makes a 4-ton rock, God can lift a 4-ton rock. God can create a rock of any weight and still have the ability to lift it. Therefore, there is no such thing as a rock too heavy for God to lift. The existence of such a rock is itself a logical impossibility.
Some object at this point that if God is omnipotent, the He ought to be able to create logical impossibilities. If He cannot, then He is not omnipotent. For example, some have made the following argument:
(1) If God is omnipotent, then God can create a square circle.Of course, premise (1) can refer to any logical paradox, e.g., rectangle triangles, rocks too heavy for God to lift, and so forth. In logical notation this argument takes the form:
(2) God cannot create a square circle (according to theists).
(3) Therefore, God is not omnipotent.
p -> qThis is a valid argument known as modus tollens, so we must turn to the soundness of its premises to see if the argument fails in any respect. I concur with premise (2), so premise (1) is the key premise to be analyzed. Premise (1) can actually be broken down into further premises:
~q
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~p
1' God is omnipotent, according to theists.Note that this is an attempt to draw a conclusion from the premises of theism; thus if theists do not actually accept these premises, the attempt at a reduction ad absurdum of theism fails. The only possible objection left is that by rejecting one or more of the above premises, theists have compromised and weakened the concept of omnipotence. I will deal with this objection shortly, but for now let's look at the above premises.
2' Thus God can create or do anything.
3' A square circle is a thing.
4' Thus God can create a square circle.
Theists would overwhelmingly agree with 1'. The problem begins with 2'. Is omnipotence defined as the ability to create or do anything? The answer is "no." When theists assert that God is omnipotent, they assert:
5' God is a maximally powerful being.This means that God is the most powerful being that can exist. He can do anything that can be done. But what about premise 3'? Can God create a square circle? To answer this question, let's analyze the proposition:
6' God can create a square circle.According to 5' God is a maximally powerful being, to be defined more fully shortly. According to the Second College Edition of the American Heritage Dictionary a square is a "rectangle having four equal sides" and a circle is a "plane curve everywhere equidistant from a given fixed point, the center." Thus 6' asserts:
7' A maximally powerful being can create a four equal-sided plane curve equidistant from its center.It is abundantly clear that by definition such a thing cannot exist; a square circle is an oxymoron. But if a square circle cannot exist, then it cannot be brought into existence, i.e., it cannot be created. Hence premise 7' fallaciously states:
8' God can create that which cannot be created.This is a contradiction; thus 4' above and (1) in the original argument are unsound premises, and the argument against the coherence of theism itself can be reduced to an absurdity. Moreover, 3' is plainly false; a square circle is not a thing, nor is it even a legitimate abstraction.
Returning to 5', theists hold that God is a maximally powerful being. This means that God can do anything that can be done. God can create things which now exist, such as rocks, trees, people, planets, and stars; and He can create things which do not now exist, such as Martians--so long as their existence does not involve a contradiction.
As mentioned earlier, one might want to object that 5' is a weakened definition of omniscience--but on what grounds? One might want to assert against 5' that there can be a being X that has the power of a maximally powerful being and the ability to create oxymorons and hence that such a being is more powerful than the one in 5' (because it can do everything He can do and more). But this strategy is question-begging; it simply reasserts premise 7', even though 7' is unsound. There can be no such being X that can create oxymorons, because oxymorons cannot be created.
The overall error of the argument against the coherence of divine omnipotence is that it assumes:
9' If a Being cannot create that which cannot exist, then He is limited.But the statement "a Being cannot create that which cannot exist" is vacuous; it does not assert anything that is not evident by logical analysis, nor does it assert anything whatsoever about the nature of the Being. It is trivially true. But since it asserts nothing about the nature of God, then it fails to derive a contradiction from theistic premises and is itself reducible to an absurdity. In short, a Being cannot be faulted for not creating that which cannot exist, because that which cannot exist cannot be created. God does not lack the ability to create that which cannot exist, because there is no such ability.
To sum up, theists make two claims regarding the omnipotence of God:
10' God is a maximally powerful being.No contradiction can be derived from these two assertions. The omnipotence of God has not been demonstrated to be a logical paradox; rather the argument against omnipotence itself has been demonstrated to rest on a logical absurdity.
11' That which cannot exist, cannot be created.