St. Thomas Aquinas' objections.
St. Thomas, as so often proved the case, reckoned that he could do better. He didn't like Anselm's reasoning. First of all, given Europe's history of polytheism, paganism and conflicting religions, he thought it rather innacurate to say that everybody could accept a definition of God as aliquid quo maius cogitari non potest.
Secondly, he questioned that even if St. Anselm's definition were accepted by all, whether it could be counted as a proof in its own right.
Perhaps not everyone who hears the name "God" understands it to signify something than which nothing greater can be thought, seeing that some have believed God to be a body. Yet, granted that everyone understands that this name "God" is signified something that which nothing greater can be thought, nevertheless, it does not therefore follow that he understands that what the name signifies exists actually, but only that it exists mentally.
Pay attention to the word "actually" above. We'll come back to that when we hear from our good friend Mr. I. Kant. Next time, however, we'll be hearing from René Descartes!