Philosophy 110 - 6.3.3 The Ontological Argument for God

An ontological argument for God was proposed by the Italian philosopher, monk, and Archbishop of Canterbury Anselm (1033–1109). Anselm lived in a time where belief in a deity was often assumed. He, as a person and as a prior of an abbey, had experienced and witnessed doubt. To assuage this doubt, Anselm endeavored to prove the existence of God in such an irrefutable way that even the staunchest of nonbelievers would be forced, by reason, to admit the existence of a God.

Anselm’s proof is a priori and does not appeal to empirical or sense data as its basis. Much like a proof in geometry, Anselm is working from a set of “givens” to a set of demonstrable concepts. Anselm begins by defining the most central term in his argument—God. For the purpose of this argument, Anselm suggests, let “God” = “a being than which nothing greater can be conceived.” He makes two key points:

  1. When we speak of God (whether we are asserting God is or God is not), we are contemplating an entity who can be defined as “a being than which nothing greater can be conceived.”
  2. When we speak of God (either as believer or nonbeliever), we have an intramental understanding of that concept—in other words, the idea is within our understanding.

Anselm continues by examining the difference between that which exists in the mind and that which exists both in the mind and outside of the mind. The question is: Is it greater to exist in the mind alone or in the mind and in reality (or outside of the mind)? Anselm asks you to consider the painter—for example, define which is greater: the reality of a painting as it exists in the mind of an artist or that same painting existing in the mind of that same artist and as a physical piece of art. Anselm contends that the painting, existing both within the mind of the artist and as a real piece of art, is greater than the mere intramental conception of the work.

At this point, a third key point is established:

  1. It is greater to exist in the mind and in reality than to exist in the mind alone.

    Have you figured out where Anselm is going with this argument?

    1. If God is a being than which nothing greater can be conceived (established in #1 above);
    2. And since it is greater to exist in the mind and in reality than in the mind alone (established in #3 above);
    3. Then God must exist both in the mind (established in #2 above) and in reality;
    4. In short, God must be. God is not merely an intramental concept but an extra-mental reality as well.
A printed etching, spotted with age, shows a robed and bearded figure wearing a mitre. The figure’s head is encircled by a halo. The figure holds up two fingers of one hand to a second figure, who is propped on their side on the ground. A stream of air rises from the second figure's mouth.
Figure 6.11 Anselm’s proof for the existence of God is structured like a mathematical proof, working from a definition of the term “God” to the conclusion that God must exist. (credit: “S. Anselme, évêque de Cantorbéry (St. Anslem, Bishop of Canterbury), April 21st, from Les Images De Tous Les Saincts et Saintes de L'Année (Images of All of the Saints and Religious Events of the Year)” by Jacques Callot/The Metropolitan Museum of Art, Public Domain)

The content of this course has been taken from the free Philosophy textbook by Openstax