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WillowOne's Positions

Ontological Argument

Form

Anselm of Canterbury's version (Proslogion, 1078):

  1. God is defined as "that than which nothing greater can be conceived."
  2. It is greater to exist in reality than merely in the understanding.
  3. If God exists only in the understanding, then a greater being could be conceived: one that exists in reality.
  4. Therefore God must exist in reality.

Alvin Plantinga's modal version (1974), which William Lane Craig prefers:

  1. It is possible that a maximally great being exists.
  2. If it is possible that a maximally great being exists, then a maximally great being exists in some possible world.
  3. If a maximally great being exists in some possible world, then it exists in every possible world (since necessary existence is part of maximal greatness).
  4. Therefore a maximally great being exists in the actual world.

My Positions

  1. Is "that than which nothing greater can be conceived" a definition of God? It is a superlative in search of a referent. I can conceive of nothing that fits it, and nor, I suspect, can anyone else.
  2. What is "greatness"? The argument requires a single, objective scale of greatness on which existence ranks above non-existence, and it never supplies one. Greater at what?
  3. Existence is simply asserted to be "greater" than non-existence, without justification. Immanuel Kant's objection (Critique of Pure Reason, 1781) stands: existence is not a predicate. Saying that a thing exists adds nothing to the concept of the thing; it says that the concept is instantiated. A hundred real thalers contain not a coin more than a hundred imagined ones.
  4. The same argument can be run for the "greatest" anything, without making anything real. Gaunilo of Marmoutiers, a contemporary of Anselm, made this point with a perfect island. Defining a dragon as existing does not make it so.
  5. This is begging the question with extra steps (Circular Reasoning). The conclusion is smuggled into the definition.
  6. The modal version fails at premise 1. "Possible" is doing all the work. If "possible" means merely "conceivable", then the inference to necessary existence does not go through. If it means "metaphysically possible", then the premise simply asserts that God exists in some world, which is what was to be proved. One can run the argument in reverse: it is possible that no maximally great being exists; therefore in some possible world none does; therefore, since such a being would have to exist in every world, it exists in none.
  7. No one has ever been argued into belief by the ontological argument, and even its defenders tend to admit that it feels like a trick. An argument that produces a conclusion about the world from definitions alone should be treated with suspicion by default.

Also see