who created God, with some help from the ontological argument

A common question skeptics pose to theists is 'if God created the world then who (or what) created God?'.
The question itself rests upon a philosophical principle we usually take for granted in everyday life, namely Leibniz's Principle of Sufficent Reason (or PSR for short). The PSR can come in several different versions but essentially states that whatever exists has some kind of explanation for its existence. Some philosophers have denied the PSR and instead have opted for what they call 'brute facts' i.e. some things just don't need any explanation for their existence and just exist without one.

My initial response to this is simply to ask why is it that anyone should think God needs an explanation for His existence? The reason most people think this is because they confuse God's type of existence as being in the same category as that of the rest of the universe's type of existence. By this I mean (to use some philosophical terminology here) most people assume that God has 'contingent' existence i.e. His existence is in need of some kind of explanation, the way the rest of physical reality requires such an explanation. Indeed, it seems obvious to us that things such as tables, chairs, people, planets etc. have satisfactory explanations as to where they came from. Even the entire universe itself seems to be subject to such a possible explanation (though it's not quite as obvious as the other entities just named what that explanation may be). This is because we intuitively recognize that such objects as tables, chairs, people and even the universe itself are merely contingent in their existence. Contingent existence simply means that such things might not have existed i.e. this chair I'm sitting on might never have come into being if the carpenter who made it had instead decided not to do so. Or even I myself might never have existed if my parents hadn't of met, got married and procreated. We also seem to intuitively recognize that even the universe itself might not have existed - we seem to be able to imagine (or at least have some kind of intuition) that nothing at all could have 'existed' instead of what we now experience. This is the definition of contingent existence - the possibility of a thing's being different or of it's not existing at all.

By contrast 'Necessary' existence is the kind of existence a thing has when it could not fail to exist or be any different from what it is. Here such mathematical propositions as '2+2=4' are considered to be 'necessarily' true, because the answer cannot be any different from the one it is i.e. '4'. There is no logically possible world in which the answer to '2+2' is '5'. This is the definition of 'necessary' – something which cannot be otherwise. Notice here that such a necessary truth has no reason for its explanation, it just is so in virtue of its nature or its definition. The ancient Greek philosopher Plato (as well as many philosophers today) thought that things such as numbers, propositions, sets and the 'forms' of concrete existence exist abstractly i.e. beyond the spatio-temporal world. Such abstract existents, if they exist at all, must exist necessarily i.e. cannot not exist.
There is some philosophical debate as to whether or not there are necessarily existent things such as numbers, sets, forms etc. but the actual formulation of necessary existence is well understood and if such things do exist they must exist necessarily. And, again, this entials that such things need no explanation for their existence – they simply exist by the very necessity of their own nature.

Now back to the question of who (or what) created God. Once again this skeptical question seems to presuppose that God, much like objects in the universe, has contingent existence and, thus, needs some kind of explanation for why He exists. But why can God not have necessary existence instead?

Indeed it actually seems obvious that if God exist then He must exist necessarily (and thus require no explanation for His existence). This can be seen from a variation of the famous ontological argument of St. Anselm. In this argument Anselm asks us to imagine the 'greatest conceivable being' (which we use the term 'God' for short) with all the attributes we would usually associate with such a being i.e. omniscience, omnipotence etc.etc. He then goes on to suggest that if such a being existed, but existed only in our imagination and not in reality, then it would not be as perfect as a being which has exactly those same qualities and yet existed in reality instead (as opposed to only in our imaginations). Now there are problems with this argument, famously made by Immanuel Kant i.e. that Anselm treats existence as a predicate or property of a thing when it is not. But, more recently, there have been forms of the ontological argument that use both necessary and contingent existence (called 'modal' ontological arguments). Essentially it seems that, upon reflection, it's obvious that the greatest conceivable being (or 'God') would have to have necessary existence as opposed to just contingent existence, because necessary existence is a 'greater' or more perfect form of existence that merely contingent existence, which is less perfect. So a being with all the properties of a perfect or greatest conceivable being (i.e. omnipotence, omniscience etc.etc.) and yet had only contingent existence is less perfect than a being with the same properties and necessary existence. Which means that if there is such a perfect being it must have necessary as opposed to contingent existence.

In effect what this means is that if God exists then He exists necessarily (i.e. He cannot not exist). This essentially entails that because of His necessary existence the question 'who created God' is just moot. If God has necessary existence then He needs no explanation for His existence - He exists necessarily in the same way abstract objects like numbers, sets etc. do or the way '2+2=4' is necessarily true and needs no explanation for why it is so. It is true by definition or true in virtue of its very nature.

This may seem like word games to many people, but its essential to realize that the reason most people ask such a question in the first place is because they assume that God has contingent existence. When we realize that to be the greatest conceivable being or most perfect being (which is basically the definition of 'God') such a being must have necessary and not contingent existence, we also realize that a question such as 'who created God' actually makes no sense.

Perhaps the skeptic can switch tracks here and claim, instead, that the universe itself exists necessarily - thus dispensing with the need for God's necessary existence. For reasons I haven't got time to go into almost no philosopher today (or perhaps ever, with the possible exception of David Hume) really believes that the universe has that type of existence - most accept that it is simply contingent (thought some have claimed it as a brute fact ala Bertrand Russell).

Note that this above argument doesn't prove that God exists, just that if He does exist then He exists necessarily (and if He doesn't exist, He likewise necessarily does not exist). And if God exists necessarily then He has no need of an explanation for His existence – it is true in virtue of His nature alone.