According to one of the forms of the cosmological argument (given by Aquinas and Avicenna), God exists because there must be some necessary existent. Everything we encounter is contingent, merely possible when considered in and of itself and only necessitated through another. But if it is necessitated through another, then there must be something necessary in itself which grounds everything else. It seems to me that this argument fails: first, because it does not have any force when considered in a concrete case, and second, because the nature of any given existent in question is unclear. I think that a different version of argument can be made out of the latter point, however.
So Jill is a human being, and as such is contingent. She did not have to exist; something else made her exist. This something else in the present case would be her parents. Now, the argument could be taken in two different directions. One would argue that there cannot be an infinite regress of causes in time. So her parents had parents, and her grandparents had parents, and so on, but this had to begin at some point. It is not exactly clear, though, why there absolutely cannot be an infinite regress here, and even many of the defenders of the cosmological argument have had no problem with such an infinite regress in time: Aquinas and Scotus thought such a regress possible though not actually true, and Avicenna thought it actually true. If nothing else, one is faced with the problem of a first moment: any given moment of time has the structure that it has something preceding it, and something following it. But a first moment would have nothing before it. It seems that such a concept of a first moment then would be at least as difficult to understand as an infinite regress of times.
What infinite regress does the argument disallow, then? An infinite regress of necessitation, for Avicenna, and similarly (perhaps identically), an infinite regress of actualization for Aquinas. That is to say, there are multiple causes working at the same time and not merely stretched out with the cause one moment and the effect in the next. This sort of causation would be logical or metaphysical. But what is this in our concrete example? Why say that there is anything to Jill's existence beyond what her parents gave to her? Once we have explained the physical act of generation, we have everything we need. Or perhaps we could allow in other causes at the same level, but nothing on a fundamentally different level. Any talk of possibility and contingency beyond this is over-abstraction which does not explain actual, concrete existents and so does not command any assent as to a first, necessary Existent whose being is simply is existence.
Second, the argument seems to assume that Jill is an existent. But this would seem to assume that she is an individual, such that we can put her together with other individuals and count each up. Jill and Susan together in a room would then make two individuals. But for this to be the case, there must be a clear-cut logical (not merely practical!) distinction for each individual. There must be an exact criterion of life and death, and of spatio-temporal location. But it would seem that one could pull a sorites paradox for any suggested definition. I can't see any reason for saying that their individualities are anything beyond practical constructions on our part for dealing with a confusing world. Since we start off in life making practical distinctions and only afterward make these practical distinctions precise, the onus is on my opponent to argue for why there are metaphysically as opposed to practically distinct individuals: how do we cross the gap from what is merely practical? But without metaphysical individuals, what is there around to be a merely possible existent? If anything, since the existent (and therefore its possibility) is grounded in our construction of it, the "cosmological" argument would prove the necessity of our stipulation (or better: what for practical purposes could be considered our stipulation, since we ourselves are are stipulating are constructions, as is any talk of constructions. Just as talk of mid-sized objects makes sense whether or not we think they exist metaphysically, it would seem that all this is practically meaningful even without a firm metaphysical foundation).
But there seems to be something we can take from the latter point. There is some reason why we construct "Jill" and "Susan", as well as "this tree" and "that stone". These may not be individuals we can consider on their own, such that they are real albeit contingent existents, but there must be some particularity which allows us to construct these forms.
"Particularity" is not the same as "individuality" in the way I am using it (perhaps my usage is arbitrary; all I am concerned with is that some distinction is made). If Jill is an individual and Susan is also an individual, than there are two defined and delimited individuals. If Jill and Susan each have particularity, though, then we cannot say how many individuals there are, or even if the question makes sense. Particularity undergirds any other statement of quantity, quality, construction, or the like. There is not a "this something" involved; there is merely the "this".
"Jill" and "Susan" then refer to particulars, but the construction makes them out to be individuals: something defined, delimited, and countable. We need this delimitation to think about them, we need some completeness. And here is the problem: nothing exists merely as incomplete. Such a thing would be only partially actual, but every actuality is actually actual. We may speak of, say, an incomplete paper. But what is already down is completely actual; it is the mismatch between our expectations and what is there that introduces the incompleteness, not anything in the bits and bytes or ink and paper themselves. (I think this point needs to be qualified, but I'll perhaps do that in a later post after we get some of the basics down here.)
But while our construction has this foisted completeness or incompleteness, the actuality itself is on the one hand incomplete, and on the other hand complete. Insofar as I mark off simply this little section of reality, it is incomplete. Physically, this computer screen is affected by gravitational forces from the farthest quasars and cannot be completely delimited as an individual without reference to them. They are not something external, but part of the very makeup of this screen itself, however minutely. I currently am constituted by the actual contents of my perception and consciousness: sight is nothing without a seen and intellect is nothing without an intellected, so any reference to me as a separate individual which sees without what it sees, points to something incomplete. This incompleteness, though, is an incompleteness precisely because it is impossible. The incomplete being is lacking something which it logically needs: not as something to bring it into existence or that previously brought it into existence (as with the version of the cosmological argument which I reject), but as what constitutes it here and now. It is the internal constitution of the being which needs explanation, not external factors or its existence in general.
So the fact that we can point to particularities means that we can pick out these incomplete beings. But the notion of an incomplete being is incoherent without its completion. So there must be complete being, some unity of being. I am inclined to say that this includes at least everything involved in any given causal system, but that would be another argument. There may even be levels of different completions, or perhaps different degrees of incompleteness and unity, which are again separate issues.
The incomplete beings would be particular expressions of complete being, since all of them are nexuses of complete being in a way; my computer screen (or at least its completion which is demanded by the incomplete being which I am regarding) is being regarded in one way, and distant quasars are this being regarded in another way, perhaps under a complex coordinate change. Perhaps one could take an analogy: the axioms and rules of inference of a mathematical system already have determined the entire rest of the system, such that they logically entail as their completion all of the system's theorems, while each theorem is the complete system regarded in a different way, or at least complete portions of the system regarded differently (though I question whether most of reality can be made precisely definite at all without violence). But the computer simply regarded in itself is not the complete being. The computer in itself is in fact merely an illusion, since we would take what is really incomplete (and so therefore unthinkable as such) and regard it as complete, just as the axioms regarded in themselves without any entailments have not been understood but have merely formed some basic intelligible impression (although again, the computer may be more purely illusion since it would seem to lack the definiteness of the axioms).
The presence of incomplete beings then logically entails complete being, and the incomplete beings are expressions of the complete being, illusory when considered simply in themselves and theophanies when considered in their completion. What this cosmological argument arrives at is perhaps different from "that which we call God", but it avoids hierarchical notions of causation which do not appear to have any concrete correlate.
This is my attempt to formulate an argument from the unity of being, as found in the Neoplatonists, the school of Wahdat al-Wujud in Islam, in Vedanta (expecially Advaita Vedanta), or in some schools of Buddhism; the analogy from mathematical systems in fact comes from Plotinus. It is not, then, an argument "for God" in the sense of some Creator completely distinct from creation.
Is the complete being itself delimited? The false completion of incomplete beings does involve delimitation, because there are other beings separated out from them. A complete being which does not have anything else, complete or incomplete, over and against it would not seem to have this delimitation. So it is not the degree of delimitation itself which makes something complete, but rather delimitation may already be a sign that something is incomplete since what is truly complete does not need to be marked off.