One of the most famous arguments for the existence of God was written by Saint Anselm of Canterbury and goes as follows:
- God is that which nothing greater than can be conceived
- It is greater to exist in reality and in the understanding rather than in the understanding alone
- Therefore, God exists in reality
There are many technical points that I’m not going to get into here but suffice it to say that the argument is actually much stronger than it appears at first glance. There are plenty of references listed on Wikipedia if you want to learn more.
This is far from a definitive refutation of Anselm’s position but after having seen this argument once a semester for the past few years as a philosophy major I have finally come to a peace of sorts with Anselm’s position (a position that to me at least seems to be patently false).
It has yet to be proven that it is possible for something existing in reality to be infinite. In other words, there is no thing today – not even the universe or a particular number – that you can point to and say “hey, this ___ is infinite” (fact). Understand we do have symbols that represent the infinite (like ∞ for numbers) but these symbols themselves are not infinite. In each of these cases the infinite exists in our understanding and the finite symbol exists in reality.
God – or that which nothing greater can be conceived – by definition must be infinite (becuase if he/she/it was not infinite then something greater could always be imagined). Thus, unless someone can show that it is possible for some infinite thing to exist in reality, it must be the case that it is greater to not exist in reality than to exist in reality and therefore God cannot (by definition) exist in reality.
[Any argument attempting to show “finite, real existence” is greater than “infinite existence in the understanding (or anything else)” dissolves into absurdity very quickly]