Atheist Brain

exploring the cognitive foundations of religious belief

Refuting the Ontological Argument


Technically speaking the ontological argument is a positive a priori argument for the existence of God. However, the ontological argument is good for nothing except providing comfort and assurance to those already convinced of God’s existence or better still confusing one’s opponent. In practice it is a defensive argument.

The ontological argument is nothing more than word-jitsu designed to move the argument onto a philosophical battleground where it is assumed the opponent will be unprepared.

It will win no converts.

When facing an opponent who is using an ontological approach to prove God’s existence, it is useful to keep the following questions in mind:

Are there any hidden presuppositions/ premises? If so what are they?

Do the hidden presuppositions/ premises hold up under scrutiny?

Is there any content to the claim being made or is it instead a tautology devoid of substance?

The ontological argument takes two main forms. The original version of the argument was originally proposed by Saint Anselm of Canterbury ~1000 years ago and looks like this:1

  1. Our understanding of God is a being than which no greater can be conceived.
  2. The idea of God exists in the mind.
  3. A being which exists both in the mind and in reality is greater than a being that exists only in the mind.
  4. If God only exists in the mind, then we can conceive of a greater being—that which exists in reality.
  5. We cannot be imagining something that is greater than God.
  6. Therefore, God exists.

There are several hidden premises that Anselm’s argument presupposes. These are the most fallacious and glaring examples (at least in my mind) but I am sure there are more:

  1. To exist in the mind is somehow the same as to exist in reality. Therefore these two kinds of existing are comparable.
  2. Existing is “greater” than not existing.

It should be obvious that there is something wrong with the first premise. The concept of a dragon which exists in the mind is nothing like a physical dragon which would exist in reality (if dragons existed). It is not a smaller or less perfect dragon, it is a mere thought. The imagined dragon does not, in any sense, exist in the way that an actual dragon exists.

The difference is a difference of kind not of degree.

Furthermore, a dragon does not spring into being just because I imagine that the greatest dragon of which I am able to conceive is one that actually exists.

We’ll turn to Kant’s critique of pure reason to try and understand why the 2nd earmarked premise fails momentarily, first let’s take a look at the 2nd form that the ontological argument commonly takes. This form of the argument, which takes advantage of modal logic, has been refined by philosopher Alvin Platinga; it looks something like this:1

  1. A maximally great being (God) is one whose greatness is unexcelled in every possible world.
  2. Such a being would, if it existed, be omniscient, omnipotent, and perfectly good.
  3. If such a being exists in some possible world, it must exist in all possible worlds (in order for maximal greatness to be achieved).
  4. It is at least possible that in some possible world God exists (even if the probability is no greater than that of a teapot orbiting our Sun in some possible universe).
  5. Unlike a teapot, God is maximally great. His maximal greatness means that his existence is stable across all possible worlds.
  6. Therefore, if God exists in some possible world, he must exist in every possible world—including the actual world.

Essentially this argument suggests that the possibility of God’s existence necessitates his existence. The notion of “maximal greatness” necessitates existence and so the argument’s conclusion, “God exists,” is stowing away in the first premise, which begs the question (this is also a tautology, a statement which cannot be false).

Jim Holt, the author of “Why Does the World Exist,” has this to say regarding the modal ontological argument, “Unhappily for partisans of the ontological argument, this logic cuts both ways. There is nothing inherently self-contradictory either in the supposition that a maximally great being does not exist… by parity of reasoning, there must be a possible world in which [God does not exist]. But if God is absent from any possible world, he is absent from all possible worlds—in particular, he is absent from the actual world.”2

Finally, let’s take a look at Immanuel Kant’s refutation of the ontological argument paraphrased from Kant’s Critique of Pure Reason. Kant unpacks the premise “existing is greater than not existing,” or more precisely he unpacks what it is to “exist” at all.

The ontological argument wrongly claims that “existing” is a predicate or attribute possessed by the subject God. Kant says “Existence is evidently not a real predicate … The small word is, is not an additional predicate, but only serves to put the predicate in relation to the subject.” Kant is claiming that “existence” is nothing more than the infinitive of the connecting verb “is.” It is a verb and not a predicate. Existence is not an attribute (like the color red) which something may or may not possess.3

If a thing exists then it necessarily exists, if not then not. Essentially Kant is claiming that the fact of a thing’s existence cannot be resolved a priori (from pure reason), but must be resolved a posteriori (with evidence).

Also, it’s worth pointing out that every religion can avail itself of pure reason in attempting to prove the existence of its respective deity.

If a Christian or a Muslim wants to prove that his religion is the one true religion, he is going to have to open us his holy book and start digging through the historical record. In short, as Christopher Hitchens frequently said, “even if I grant you the existence of God, you still have all your work ahead of you.”

Wikipedia, The Ontological Argument1
Jim Holt, “Why Does the World Exist?”2
Wikipedia, Immanuel Kant Critique of Pure Reason3

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