Abstract

The article is an attempt to make a logic analysis of the Saint Anselm’s of Canterbury ontological proof on the existence of God. Leaving the issue of God’s existence aside, the author tries to find out whether the proof is formally proper. To do so the author tries to translate its assumptions into formal language and reconstruct the argument based on the assumptions. The analysis, however, shows that it is impossible to translate the proof into the predicate logic language. Anselm’s text is based on antinomies caused by the predicative use of the word "exist" next to the existential quantification. What is also problematic is the usage of two contradictory descriptions – according to Anselm’s proof one may think that a given object "exists" and at the same time one "may not" think that it "exists".