The Proslogion contains the ontological argument that made Anselm famous throughout the ages. In this work, God is not thought of as the sum of positive qualities and the all-powerful possessor of various earthly goods. Anselm’s reasoning no longer proceeds from a conception of what God must be to assert that something corresponding to this conception exists. On the contrary, the philosopher finds the definition of what can not exist. And having easily proved that the object behind such a notion exists, he afterward calls it God.
The reasoning of Anselm has faith as its starting point – it is here that he finds the definition of God, to which he ultimately returns. This may give rise to the claim that Anselm’s argumentation does not go beyond faith. Its beginning and conclusion are rooted in Revelation, and the process of discovering the truth of God’s being is a religious practice rather than philosophical reasoning. In response, however, Anselm may well argue that his judgments can also be understood rationally, that is, apart from faith. Anselmo regards his argument precisely as proof and claims the necessity of its conclusion not only for the believer but also for any non-religious person.
I cannot entirely agree with Anselm when he compares ideal being with actual reality. Anselm is not comparing existence with other existing or thought with existence, but thought with another thought. Since this argument has only to do with consciousness, its actual result is that any reasonable person, understanding Anselm’s definition of God, cannot think that God does not exist. To this, the author of the Proslogion would most likely argue that since the proof is reasoning, which makes a doubtful thing credible, his argument should be considered sufficient to explain the existence of God.