A Primer for Understanding Ontological Arguments for the Existence of God

Here’s a very brief history of the Ontological Argument for the existence of God: Italian Anselm originated it around the 11th century. Italian Thomas Aquinas rejected it in the 13th century. Frenchman Rene Descartes resurrected it in the early 17th century. Prussian/German Immanuel Kant refuted it in the latter half of the 17th century. Then in the past several decades Americans Norman Malcolm, Charles Hartshorne, and Alvin Plantinga have all defended it. Criticisms and debate about it abound in almost every philosophy textbook.


It is generally agreed that the Ontological Argument never converted anyone (even though Bertrand Russell once thought it was correct, but later changed his mind). It is an amazing argument—a philosopher’s delight! This is the “most famous, the most mystifying, the most outrageous and irritating philosophical argument of all time.” “It remains as one of the most controversial arguments in all of philosophy.” Yet, “whenever I read the Ontological Argument, I have the same feeling that comes over me when I watch a really good magician. Nothing up this sleeve, nothing up the other sleeve; nothing in the hat; presto! A big fat rabbit. How can Anselm pull God out of an idea?” [Robert Paul Wolff in About Philosophy, (pp.284ff)].

Anselm’s Ontological Argument for the Existence of God:

1) On the assumption that that than which nothing greater can be conceived is only in a mind, something greater can be conceived, because
2) Something greater can be thought to exist in reality as well.
3) The assumption is therefore contradictory: either there is no such thing even in the intellect, or it exists also in reality;
4) But it does exist in the mind of the doubter;
5) Therefore that than which nothing greater can be conceived exists in reality as well as in the mind.

Anselm argued that even those who doubt the existence of God would have to have some understanding of what they were doubting: Namely, they would understand God to be a being than which nothing greater can be thought. Given that it is greater to exist outside the mind rather than just in the mind, a doubter who denied God's existence would be caught in a contradiction, because he or she would be saying that it is possible to think of something greater than a being than which nothing greater can be thought. Hence, God exists necessarily.

The basic Kantian criticism of Anselm's argument is that someone cannot infer the extra mental existence of anything by analyzing its definition. Yet defenders reply that Anselm is not defining God into existence. He’s asking whether we can reasonably suppose that something than which nothing greater can be conceived exists only in the intellect. Consider these statements: “No square circles exist,” and “an infinite set of prime numbers exists.” If we can move from concepts to statements about reality here with math, then why not with God?

However, if we asked an Easterner what he conceives to be the greatest conceivable being, his conception will start off being different than those of westerners from the get-go. I think Anselmian arguments, including those of Hartshorne, Plantinga and Malcolm's all begin with Occidental not Oriental conceptions of God, and their western conceptions of God are theirs by virtue of the prevalence of the Christian gospel in the west. If ontological argumentation is sound, then the eastern conceptions of God will entail that their God (or the One) also exists. Since these two conceptions of God produce two mutually exclusive conclusions about which kind of God exists, then the ontological argument itself does not lead us to believe in the Christian God alone.

John Hick says this about Plantinga’s formulation: “the reasoning looks suspiciously like an attempt to prove divine existence by definitional fiat. I believe that the suspicion is justified. Plantinga’s argument for a maximally excellent being, if valid, would also work for a maximally evil being.” [Which Hick offers in An Interpretation of Religion (Yale Univ. Press, 1992), pp. 78-79]. But there cannot be two omnipotent beings, one being good and one being evil, even though the ontological argument could prove that they both exist. Since the ontological argument can be used to prove that two mutually exclusive beings both exist, the reasoning itself is faulty.