It may be strange to some that there are philosophical objections raised by Christians against arguments for belief in God. For example, St. Anselm’s “Ontological Proof” (as it would come to be called) was taken under a critical lens when Thomas Aquinas (1225-1274) took consideration of the argument in his epic Summa Theologiae (ST hereafter). Over the last year or so, I have written numerous defenses of Anselm’s argument as well as criticisms so as to see if we have a legitimate and defensible argument for God’s existence.
Gaunilo and Kant’s criticism aside, there are several other considerable objections to the argument that I think are serious enough to address. Two in particular come to mind. Mortimer J. Adler (1980) makes the point in his book How to Think About God that existential propositions do not entail logical necessity. As he writes at length:
No existential proposition can be self-evidently true or necessarily true. When we have direct perceptual acquaintance with a particular individual, the existence of that individual is evident to us, but the proposition which asserts that the individual exists is not self-evident, nor is its truth necessary. Self-evident propositions are propositions which we know to be true directly from our understanding of their component terms, not by process of reasoning or inference. (Adler 1980: 104)