Saint Anselm, the author of the book The Proslogian came up with what is believed to be the first formulation of the ontological argument. The writings of the ontological argument in The Proslogian were Anselm’s reflections of the passage Psalm 14:1 “Fools say in their hearts ’There is no god’” and directs his argument at the ‘fools’ From this passage. Ontology means the study of being so therefore Anselm’s argument is formulated to prove the existence of god through the study of being. Anselm formulates 2 ontological arguments for the existence of god.
Anselm’s first argument is based on three premises followed by a conclusion. The first premise is that God is the greatest conceivable being. For someone to say ‘there is no God they must first have conceived an idea of what God is and Anselm suggests that god is usually conceived as the ‘greatest conceivable being’. He then followed this with the premise that God exists either in the mind alone or in the mind and reality as well. His third premise is that that which exists in the mind and in reality is greater than that which exists in the mind alone. For example unicorns may exist in the mind as a great concept but anything that exists in reality would be greater than the concept of the unicorn. Anselm therefore states that an idea that exists in the mind and reality has an extra quality in comparison to the idea that exists in the mind alone, this quality being existence. From this he therefore concludes that god must exist in reality as well as the mind because he is the greatest conceivable being.
In his first ontological argument, Anselm looks at the existence of god as a predicate. A predicate means an quality or intrinsic property of something. For example a bachelor refers to a man who is unmarried so when you say someone is a bachelor you wouldn’t need to state that they are unmarried as it is a predicate of being a bachelor. Much in the same way Anselm