When one considers ontological arguments for Gods existence it is very natural to start with Anselm’s ontological argument. It is also the case that for most freshman, that are not well versed in philosophy but very curious about theology, to accept the arguments as if it proves God’s existence. Well I came here to burst your bubble as I explain what the argument really does.
Let’s begin with restating the argument:
- I can conceive of a being than which no greater can be conceived.
- If a being than which no greater can be conceived does not exist in reality but only in the mind alone, then I can conceive of a being greater than a being than which no greater can be conceived—namely, a being than which no greater can be conceived that exists in reality not merely in the mind alone.
- I cannot conceive of a being greater than a being than which no greater can be conceived.
- Hence, a being than which no greater can be conceived exists.1 (citation)
Premise 1 establishes the definition of God (and our ability to conceive of him) so far so good. Premise 2 is an argument from contingency. Basically the being which exists in reality is greater than the being which exists in my mind since the being which exists in my mind is contingent upon me the thinker for its existence. Premise 3 is to make a modus tollens move, (to assure logical validity). Thus premise 4 follows deductively. So what does this mean? Does God now just exist? The answer is no and this is why.
Ontological arguments cannot truly prove anything, (by this I mean they do not demonstrate some things existence) since they presuppose the existence of something. For example Alvin Plantinga, a contemporary philosopher, proposed what he calls the “victorious ontological argument.”1 In this victorious version, Plantinga uses 20th century modal logic to convey the idea that if God is possible then he is necessary and if he is necessary then he exists. This argument seems to be a non-starter for most since you must first accept the existence of God. Surprisingly the theist, Plantinga, admits to this. Plantinga writes “Our verdict on these reformulated versions of St. Anselm’s argument must be as follows. They cannot, perhaps, be said to prove or establish their conclusion. But since it is rational to accept their central premise, they do show that it is rational to accept that conclusion”1According to the Standford Encyclopedia of Philosophy, this is akin to saying “Either God exists or 2+2=5. It is not the case that 2+2=5. Therefore God exists.” In both arguments if someone doubts the existence of God then they are going to wind up with a false premise.1 If someone already does not accept the premise God exists, then one must also cast doubt to God being possible, or for that matter, a being of which no greater can be conceived.
1. Oppy, Graham, “Ontological Arguments”, The Stanford Encyclopedia of Philosophy (Winter 2012 Edition), Edward N. Zalta (ed.), URL = <http://plato.stanford.edu/archives/win2012/entries/ontological-arguments/>.