One way to show why Bertrand Russell thought the ontological argument was bad grammar is to point out its reductio ad absurdum when applied to something other than God. Anselm’s eleventh-century version of the ontological argument went something like this:
1. God is a being than which no greater being can be conceived.
2. If God exists only in conception, and not in reality, then he could be conceived to be greater than he is.
3. Therefore, God must exist in reality.
This silly argument was countered in Anselm’s day by Gaunilo, who used it to “prove” the existence of a perfect island. But we could do the same thing with nothingness:
1. Utter nothingness is a void than which no greater void can be conceived.
2. If utter nothingness exists only in conception, and not in reality, then it can be conceived to be greater than it is.
3. Therefore, utter nothingness must exist in reality.
Therefore, nothing exists. Putting the two bad-grammar arguments together, we could prove that God is Utter Nothingness.
Dan Barker, Life Driven Purpose, pg 137