Explanations, and the understandings they mediate, must all terminate (at least in principle) upon *some singularity or other* if they are to hang together – if they are to succeed as explanations by satisfying our urge to understand. This is as true for explanations of singular phenomena as it is for explanations of regularities. Science then, of any sort, has no alternative but to adduce some singularity or other as the original fact or truth at the basis of all others. The terminus ad quem of the scientific project must be an account of the terminus a quo of all things: a terminal singularity. This, whether the posited singularity be a historical event such as the Big Bang, or a fundamental equation that can work as a Theory of Everything, or what have you.
But only one sort of terminal singularity can ultimately succeed – not at completing inquiry, for (per Gödel) that completion is not possible to finite beings, but rather at satisfying them that things cohere intelligibly. Only one sort of terminal singularity can set the scientist’s mind finally and fully at ease.
Terminal singularities may be quite concrete events. Indeed, perhaps they must be. Aristotle, Augustine, Aquinas and Whitehead all insist in their various ways that concepts such as the Platonic Forms cannot be coherently conceived except as aspects of some concrete actual that, as actual, so is eventual. But however concrete they may be, we cannot observe terminal singularities as objects of our study, and as it were from “outside” them; for, being ourselves numbered among the items that our science would hope to explain as derivates of the completely satisfactory terminal singularity we hope to identify, we are inescapably “inside” that singularity. We cannot observe, e.g., the Big Bang as if we were outside it, because we are in it. Nevertheless, whatever the character of the terminal singularity in and by which we subsist, that we cannot observe it as we observe other events that likewise derive from it should not trouble us; terminal singularities are not after all the explananda of science, are not the matter of its investigations, but are rather its explanans.
If only because our time is limited, all procedures of explanation must soon halt upon some sufficiently satisfactory originating fact, where we may pause for a while at an explanation that is “good enough” for our proximal purposes, and for the time being. But such halts to inquiry cannot fully and permanently satisfy. They are felt as inherently provisional, and awaiting further work, that is needful, and must sooner or later be undertaken. The longer that work is deferred, the greater the bedevilment of our thought.
An explanation of an originating event that terminates upon the event itself – that says, “this event is a brute fact,” or that, “this event is causa sui” – can fail to explain. Where it is not due to a simple failure of nerve, to invincible ignorance, or to lassitude, it amounts to an implicit assertion that the event in question is just inexplicable, by anyone; that it is not the sort of thing that can be explained in the first place.
But such an assertion is not necessarily problematic, for there are two sorts of brute or causa sui items that can operate as terminal singularities of a theory: those that are ultimate, and those that are not. Only the latter sort are troublesome.
If an explanation terminates upon any singularity that is not ultimate – that, i.e., is not both necessary and supreme – then it begs the very question that lies at the root of all inquiry: “why is this what it is?” It is therefore incomplete. It fails. Implicitly, also, it rejects the very notion of explanation, and so of the possibility of understanding our experience, at least by default. E.g., “the quantum vacuum is the basis of everything, and it has no basis, it’s just there.” Such statements are tantamount to “stuff happens, and in the end that’s all there is to be said.”
However great the explanatory power of any subultimate terminal singularity – say, the Big Bang Theory as a skeleton key to cosmogony – it cannot quite succeed as an explanation, because it cannot quite finish the job we set for it. Nor likewise could a discovery (per impossibile) that there is, or must logically be, a universe of universes, which gave rise to our own Big Bang. The Big Bang may indeed be the terminus a quo of all the events of our cosmos, so that the Big Bang Theory is coherent and competent so far as it goes; and the Big Bang may itself be explained as one item among a limitless array of similar items. But, as contingent, neither the Big Bang, nor an array of such Bangs, nor even a universe of such arrays, can relieve the irritant inner itch of misunderstanding and anxious confusion that is the spur of all inquiry, all deliberation.
It might be objected that an explanation that terminates on an ultimate singularity likewise fails. But not so. The ultimate is not indeed explainable, to be sure, even in principle. It is given, as a brute fact that cannot be adduced to the effect of some other fact. So very given is it, that any attempt at such an adduction is inapt – not even wrong. But, unlike a terminal singularity that is contingent, and that therefore cries out for an explanation of its own, a necessary terminal singularity is conceptual bedrock – the sea bed supporting the ooze upon which the bottom turtle rests. Explanation that terminates upon necessity has arrived at the final destination of all possible philosophical inquiry, and achieved its last objective in our intellectual economy. It is not possible to go further; but then, having achieved the objective of inquiry, neither is it needful or desirable to do so.
The impossibility of explaining the ultimate is then the basis and reason of our feeling of intellectual satisfaction with explanations that terminate upon it. Until we can see how a phenomenon ties back coherently and comprehensibly (at least in principle) to its ultimate basis in an ultimate singularity, we shall continue somewhat discomfited. Once we do see how a phenomenon connects coherently with the ultimate, we can then rest in the contemplation of that ultimate, and feel quite content.
As impenetrable to our analysis, the ultimate is incorrigibly mysterious to us. Indeed, it cannot but be the most mysterious thing of all. But, curiously, and in stark contrast to our anxiety at apprehensions of other items we do not understand, the contemplation of the mystery of the ultimate is the most delicious and satisfying experience of which the intellect is capable. The mystery of the ultimate is experienced as the complete resolution and clarification of all other mysteries. Unlike all other mysteries, it gives rest and refreshment to the weary mind, happiness and delight. The success of true theory is felt as the enjoyment of theoria.