The Ontological Argument

This is the thirteenth in a series of posts responding to a list of 20 arguments for the existence of god from this article. To be fair, the article does state that these arguments don’t make a case except when taken all together, using the metaphor of a rope, but I am analyzing them individually so I have responses when I encounter the argument later in other sources.

The ontological argument was devised by Anselm of Canterbury (1033-1109), who wanted to produce a single, simple demonstration which would show that God is and what God is. Single it may be, but far from simple. It is, perhaps, the most controversial proof for the existence of God. Most people who first hear it are tempted to dismiss it immediately as an interesting riddle, but distinguished thinkers of every age, including our own, have risen to defend it. For this very reason it is the most intensely philosophical proof for God’s existence; its place of honor is not within popular piety, but rather textbooks and professional journals. We include it, with a minimum of discussion, not because we think it conclusive or irrefutable, but for the sake of completeness.

Anselm’s Version

  1. It is greater for a thing to exist in the mind and in reality than in the mind alone.
  2. “God” means “that than which a greater cannot be thought.”
  3. Suppose that God exists in the mind but not in reality.
  4. Then a greater than God could be thought (namely, a being that has all the qualities our thought of God has plus real existence).
  5. But this is impossible, for God is “that than which a greater cannot be thought.”
  6. Therefore God exists in the mind and in reality.

It’s nice of Peter Kreeft to admit how weak this argument is. I’ll show why in a bit, but I want to quote the other versions of the argument he lists.

Charles Hartshorne and Norman Malcolm developed this version of the ontological argument. Both find it implicitly contained in the third chapter of Anselm’s Proslogion.

  1. The expression “that being than which a greater cannot be thought” (GCB, for short) expresses a consistent concept.
  2. GCB cannot be thought of as: a. necessarily nonexistent; or as b. contingently existing but only as c. necessarily existing.
  3. So GCB can only be thought of as the kind of being that cannot not exist, that must exist.
  4. But what must be so is so.
  5. Therefore, GCB (i.e., God) exists.

This version is not really different, as far as I can tell. As you’ll be able to tell if you click the link, I’m skipping the questions because they are not my objections and I see no need to address them.

This variation on the modal version has been worked out in great detail by Alvin Plantinga. We have done our best to simplify it.


Maximal excellence: To have omnipotence, omniscience and moral perfection in some world.

Maximal greatness: To have maximal excellence in every possible world.

  1. There is a possible world (W) in which there is a being (X) with maximal greatness.
  2. But X is maximally great only if X has maximal excellence in every possible world.
  3. Therefore X is maximally great only if X has omnipotence, omniscience and moral perfection in every possible world.
  4. In W, the proposition “There is no omnipotent, omniscient, morally perfect being” would be impossible—that is, necessarily false.
  5. But what is impossible does not vary from world to world.
  6. Therefore, the proposition, “There is no omnipotent, omniscient, morally perfect being” is necessarily false in this actual world, too.
  7. Therefore, there actually exists in this world, and must exist in every possible world, an omnipotent, omniscient, morally perfect being.

Now, here’s my response to all of these phrasings:

  1. The greatest being I can conceive as existing, a maximally great being having omnipotence, omniscience, and moral perfection, would not permit evils such as child rape, child cancer, earthquakes, birth defects, or tsunamis in any world.
  2. Evils such as child rape, child cancer, earthquakes, birth defects, and tsunamis do exist in the only word we are sure exists.
  3. Therefore, that being (god) cannot exist.

The theist can only respond two ways: abandon the Ontological Argument, or say that it is greater to allow child rape (and those other evils) than prevent it.

My morals do not allow permitting child rape. If you agree that that is the most moral position on the issue, you must admit that your god, should he exist, is less moral than I am, not all-powerful, or not all-knowing, and therefore cannot be proved by the ontological argument. If you disagree, please reconsider, as you are saying that hurting children or allowing them to be hurt by not interfering is or can be superior to saving them.

I see little reason to waste further words on my own rebuttal to this argument; others have surely done better. Although, I will call bullshit on every possible world having the same set of impossible things (number 5 in Plantinga’s version). We have no way of knowing that and no reason to assume it.

2 thoughts on “The Ontological Argument

  1. The ontological argument is just behind the presuppositional argument on my list of “worst arguments in apologetics.” Both simply try to define God into existence, although the ontological argument at least has the decency to make an attempt at rationality.

    1. Agreed. The ontological argument is a real argument, although one quite easy to refute on multiple levels. Presuppositional apologetics cannot possibly convince anyone who doesn’t already believe on some level, I would think.

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