One of the most fascinating arguments for the existence of an all-perfect God is the Ontological argument in its different versions. Though there are several different versions of the argument, all purport to show that it is self-contradictory to deny that there exists a greatest possible being. Thus, this general line of argument, it is a necessary truth that such a being exists; and this being is the God of traditional western theism.
Throughout the years since St. Anselm of Canterbury first published the original version of his ontological argument for God’s existence in the Proslogium, many have come to criticize and analyze the logic behind his famous argument. What separates this argument from others in providing formal proof for God’s existence, was that it had used entirely a metaphysical, apriori method of establishing the existence of God, rather than an empirical method as was used by the cosmological argument. Anselm began his argument, claiming that there were two types of existent beings within this world, those who were necessary, that is beings who were needed to exist and contingent beings who existed, but whose existence was not entirely necessary. He then continued to define God as “something that than which nothing greater can be conceived” (12).
It is worth reflecting for a moment on what a remarkable (and beautiful) undertaking it is to deduce God’s existence from the very definition of God. Normally existential claims don’t follow from conceptual claims. If I want to prove that bachelors, unicorns, or viruses exist, it is not enough just to reflect on the concepts. I need to go out into the world and conduct some sort of empirical investigation using my senses. Likewise, if I want to prove that Bachelors unicorns, or viruses don’t exist, I must do the same. In general, positive and negative existential claims can be established only by empirical methods.
There is, however, one class of exceptions. We can prove certain negative existential claims merely by reflecting on the content of the concept. Thus, for example, we can determine that there are no square circles in the world without going out and looking under every rock to see whether there is a square circle there, we can do so merely by consulting the definition and seeing that it is self-contradictory. Thus, the very concepts imply that there exist no entities that are looth square and circular.
The ontological arguments, then is unique among such arguments in that it purports to establish the real (as opposed to abstract) existence of some entity. Indeed, if the ontological arguments succeed, it is as much a contradiction to suppose that there are square circles or female bachelors. In this study, we will evaluate a number of different attempts to develop this astonishing strategy.
St. Anselm the originator of the ontological argument, which he describes in the Proslogium as follows:
Even a fool, when he hears of a being than which nothing greater can be conceived understands what he hears, and what he understands is in his understanding. And assuredly that, than which nothing greater can be conceived, cannot exist in the understanding alone: then it can be conceived to exist in reality; which is greater. Therefore, if that, than which nothing greater can be conceived, exists in the understanding alone, the very being, than which nothing greater can be conceived, is one, than which a greater can be conceived. But obviously, this is impossible. Hence, there is no doubt that there exists a being, than which nothing greater can be conceived, and it exists both in the understanding and in reality (46).