For Anselm, using logic that can be deducted about God, it is clear to see that God’s existence is necessary. In the second ontological argument from Anselm, God is the greatest being possible; it is greater to exist by necessity than by contingence, it is therefore, impossible for God to not exist. In this argument, God’s existence is an analytic statement, it is impossible to prove that God exists and although Anselm believes that it does not need to be proven, there is no way of knowing that it is analytic.
For example take triangles, every triangle that anyone can ever think of will have 3 sides that all add up to 180 degrees, that is simply a part of what a triangle is. Humans can however, prove this by drawing every possible triangle and testing them to see, with God’s existence that is not possible. For humans to consider his existence as an analytic statement, they would have to go faith and logic alone.
In a way God’s existence could be a synthetic statement, which would mean that it would need to proven before the statement was true or not, the reason for this is because whether God exists or not does not prove his existence in reality as Anselm suggests in his argument. Kant would agree with this as he reviews Anselm’s ontological argument by saying that God’s existence is not a predicate, existence may be a part of the concept of God, but it does not proof that God exists.
Descarte would also agree with the statement, as in his ontological argument he sets out that God is a perfect being, a part of being perfect is existing, and therefore God must exist. Descarte also uses the idea of the triangle in his argument, he writes that even if we think of triangles having four sides, the truth will not change; the triangle will remain to have 3 sides. For Descarte the triangle is God, he believes that God is immutable and will not change even if humans think he does not exist.
Descarte would argue that logic can be used to prove the existence of God, he believes that God has instilled in humans an idea of God, which is that he is perfect, in this Descarte agrees with Anselm he then however, writes that we cannot talk of God unless he exists as a part of being God is existing. His argument, for Descarte, demonstrates God’s existence this argument is a priori and uses pure logic, and so for him God’s existence is an analytic statement.