I. Kalam Cosmological Argument
Without doubt the most well known argument for the existence for God today is the Kalam cosmological argument which features prominently in many debates between William Craig and atheistic thinkers. The Kalam cosmological argument in its simplest form goes as follows:
1. Whatever begins to exist has a cause.
2. The universe begins to exist.
3. Therefore, the universe has a cause.
This is a strong argument precisely because it is logically tight (an unassailable modus ponens). The challenge for the argument is to convince critics to accept premise 2. Craig points to the dominant scientific model of the origin of the universe, the Big Bang theory, to argue that the universe has a beginning and is therefore finite both spatially and temporally. He buttresses his argument conceptually by arguing that a universe not only has a beginning; it is also not infinite because ‘actual infinites’ are impossibilities.
The argument may not persuade critics who reject premise 2, especially the pantheist (who regards the universe as having its own ultimate and eternal significance, or the Naturalist (who insists there can be no reality beyond the physical, observable universe). Still, the argument in the end ‘smokes out’ the real reason why these critics reject the existence of God in favor of material substance ascribed with eternal/ultimate significance. Such material substance is benign and does not require moral accountability, in contrast to the moral accountability required by the personal theistic God presented by the Kalam cosmological argument.
One limitation of the Kalam cosmological argument arises from its strength. Its uses the results of empirical sciences – the Big Bang theory and mathematical discussions on the impossibility of ‘actual infinites’ (David Hilbert) – to challenge the high priests of contemporary knowledge enterprise represented by scientists who presume to have the last word about the nature of the world and ultimate reality (whatever it may be). Indeed, Craig’s debates often expose how his atheistic opponents have gone beyond their scientific expertise when they make claims that illegitimately outrun available scientific data and are accompanied by weak philosophically arguments.
Perhaps we need to be modest about what the Kalam cosmological argument can achieve. It may be too much to jump from a posteriori judgments based on data drawn from the physical, contingent universe to judgments about a necessary being (God). Even if it is granted that the universe has a cause, and that this cause must be tremendously powerful; still, this does not prove that God exists – at least not the God of Christianity who is an omnipotent personal, purposeful, rational agent. It does nevertheless prove that theism is more plausible than atheism. Perhaps that is all that one needs to deduce from a posteriori arguments.
For this reason, I prefer another version of the cosmological argument – the argument from contingency (Aquinas’ Third Way) or from the Principle of Sufficient Reason (represented by G.W. Leibniz)
II. Thomas Aquinas Third Way – Argument from Contingency (Summa Theologiae 1.2.3)
“The third way is taken from possibility and necessity, and runs thus. We find in nature things that are possible to be and not to be, since they are found to be generated, and to corrupt, and consequently, they are possible to be and not to be. But it is impossible for these always to exist, for that which is possible not to be at some time is not. Therefore, if everything is possible not to be, then at one time there could have been nothing in existence. Now if this were true, even now there would be nothing in existence, because that which does not exist only begins to exist by something already existing. Therefore, if at one time nothing was in existence, it would have been impossible for anything to have begun to exist; and thus even now nothing would be in existence—which is absurd. Therefore, not all beings are merely possible, but there must exist something the existence of which is necessary. But every necessary thing either has its necessity caused by another, or not. Now it is impossible to go on to infinity in necessary things which have their necessity caused by another, as has been already proved in regard to efficient causes. Therefore we cannot but postulate the existence of some being having of itself its own necessity, and not receiving it from another, but rather causing in others their necessity. This all men speak of as God.”
Logical Structure of the Third Way (from possibility and necessity)
1. There are beings that exist and cease to exist (i.e. there are possible beings).
2. But we cannot reduce all beings to possible beings because possible beings come to exist only through what already exist.
3. Therefore, there must be a Being whose existence is necessary (one that does not come into being and will not cease to be).
4) There cannot be an infinite regress of necessary beings where each necessary being has its necessity depends on another for two reasons (a) A dependent Being by definition cannot be a dependent Being; (b) Aquinas points to the second way – argument from efficient causality where he argued an infinite regress is impossible for unless there is a first cause of the series there would be no causality in the series.
5) Therefore, there must be a first Being that is necessary in itself (that is, not dependent on another for its existence).
III. Leibniz Principle of Sufficient Reason
G.W. Leibniz, one of the geniuses of early modern European philosophy, refined the argument into what is called the Principle of Sufficient Reason.
On the Ultimate Origination of Things (23 November 1697) from G.W. Leibniz Philosophical Essays Trans. Roger Ariew & Daniel Garber Hackett 1989, pp.149-159.
BEYOND THE WORLD, that is, beyond the collection of finite things, there is some One Being who rules, not only as the soul is the ruler in me, or, better, as the self is the ruler in my body, but also in a much higher sense. For the One Being who rules the universe not only rules the world, but also fashions or creates it; he is above the world, and, so to speak, extramundane, and therefore he is the ultimate reason for things. For we cannot find in any of the individual things, or even in the entire collection and series of things, a sufficient reason for why they exist. Let us suppose that a book on the elements of geometry has always existed, one copy always made from another. It is obvious that although we can explain a present copy of the book from the previous book from which it was copied, this will never lead us to a complete explanation, no matter how many books back we go, since we can always wonder why there have always been such books, why these books were written, and why they were written the way they were. What is true of these books is also true of the different states of the world, for the state which follows is, in a sense, copied from the preceding state, though in accordance with certain laws of change. And so, however far back we might go into previous states, we will never find in those states a complete explanation [ratio] for why, indeed, there is any world at all, and why it is the way it is.
I certainly grant that you can imagine that the world is eternal. However, since you assume only a succession of states, and since no reason for the world can be found in any one of them whatsoever (indeed, assuming as many of them as you like won’t in any way help you to find a reason), it is obvious that the reason must be found elsewhere. For in eternal things, even if there is no cause, we must still understand there to be a reason. In things that persist, the reason is the nature or essence itself, and in a series of changeable things (if, a priori, we imagine it to be eternal), the reason would be the superior strength of certain inclinations, as we shall soon see, where the reasons don’t necessitate (with absolute or metaphysical necessity, where the contrary implies a contradiction*) but incline. From this it follows that even if we assume the eternity of the world, we cannot escape the ultimate and extramundane reason for things, God.
Logical Structure of Leibniz’s Argument from Sufficient Reason
1. The whole observable universe comprises changeable things.
2. Whatever is changing does not have the reason for its own existence.
3. There must be a sufficient reason to account either for itself or for everything beyond itself.
4. Therefore there must be a cause beyond this world to account for its existence.
5. This cause must be its own sufficient reason (an infinite regress of sufficient reason is impossible since a sufficient reason accounts for itself).
6. Therefore, there must be a first Cause of the universe that has no reason beyond itself, i.e. it is its own sufficient reason.
Note that Leibniz argues even if the things of the universe were eternal, they will still require a sufficient reason for their existence, “even if we assume the eternity of the world, we cannot escape the ultimate and extramundane reason for things, God.”
IV. F.C. Copleston Argument from Contingency (1947)
Logical Structure of Argument from Contingency
1. We observe that there are contingent things in this universe – they might not have existed e.g. we would not exist without our parents.
2. Indeed, all things in the universe are contingent – none of which contain in itself alone the reason of its existence.
3. Therefore there must be a cause of everything in the universe that exists outside the universe itself.
4. This cause must be a necessary being – one which contains the reason for its existence inside itself.
5. This necessary being is God.
F.C. Copleston gave a succinct presentation of the third way in his famous debate with Bertrand Russell in the BBC Radio debate (1947). LINK
Part of the debate goes as follows (C = Copleston and R = Russell):
C: Well, for clarity’s sake, I’ll divide the argument into distinct stages. First of all, I should say, we know that there are at least some beings in the world which do not contain in themselves the reason for their existence. For example, I depend on my parents, and now on the air, and on food, and so on. Now, secondly, the world is simply the real or imagined totality or aggregate of individual objects, none of which contain in themselves alone the reason of their existence. There isn’t any world distinct from the objects which form it, any more than the human race is something apart from the members. Therefore, I should say, since objects or events exist, and since no object of experience contains within itself the reason of its existence, this reason, the totality of objects, must have a reason external to itself. And that reason must be an existent being.
Well, this being is either itself the reason for its own existence, or it is not. If it is, well and good. If not, then we must proceed further. But if we proceed to infinity in that sense, then there’s no explanation of existence at all. So, I should say, in order to explain existence, we must come to a Being which contains within itself the reason for its own existence, that is to say, which cannot not exist.
R: This raises a great many points and it’s not altogether easy to know where to begin, but I think that, perhaps, in answering your argument, the best point with which to begin is the question of a Necessary Being. The word “necessary” I should maintain, can only be applied significantly to propositions. And, in fact, only to such as are analytic — that is to say — such as it is self-contradictory to deny. I could only admit a Necessary Being if there were a being whose existence it is self-contradictory to deny. I should like to know whether you would accept Leibniz’s division of propositions into truths of reason and truths of fact. The former — the truths of reason — being necessary.
C: Well, I certainly should not subscribe to what seems to be Leibniz’s idea of truths of reason and truths of fact, since it would appear that, for him, there are in the long run only analytic propositions. [ It would seem that for Leibniz truths of fact are ultimately reducible to truths of reason. That is to say, to analytic propositions, at least for an omniscient mind. Well, I couldn’t agree with that. For one thing it would fail to meet the requirements of the experience of freedom. ] I don’t want to uphold the whole philosophy of Leibniz. I have made use of his argument from contingent to Necessary Being, basing the argument on the principle of sufficient reason, simply because it seems to me a brief and clear formulation of what is, in my opinion, the fundamental metaphysical argument for God’s existence.
R: But, to my mind, a “necessary proposition” has got to be analytic. I don’t see what else it can mean. And analytic propositions are always complex and logically somewhat late. “Irrational animals are animals” is an analytic proposition; but a proposition such as “This is an animal” can never be analytic. In fact, all the propositions that can be analytic are somewhat late in the build-up of propositions.
C: Take the proposition “if there is a contingent being then there is a Necessary Being.” I consider that that proposition hypothetically expressed is a necessary proposition. If you are going to call every necessary proposition an analytic proposition, then — in order to avoid a dispute in terminology — I would agree to call it analytic, though I don’t consider it a tautological proposition. But the proposition is a necessary proposition only on the supposition that there is a contingent being. That there is a contingent being actually existing has to be discovered by experience, and the proposition that there is a contingent being is certainly not an analytic proposition, though once you know, I should maintain, that there is a contingent being, it follows of necessity that there is a Necessary Being.
Russell refused to accept the notion of a necessary being on the ground that it is meaningless and that it is logically flawed to argue for the existence of a being (at the end of a regress of causal events) that is responsible for the existence of everything in the universe.
R: The difficulty of this argument is that I don’t admit the idea of a Necessary Being and I don’t admit that there is any particular meaning in calling other beings “contingent.” These phrases don’t for me have a significance except within a logic that I reject…I shouldn’t say unintelligible — I think it is without explanation. Intelligible, to my mind, is a different thing. Intelligible has to do with the thing itself intrinsically and not with its relations.
Copleston rebutted Russell’s assertion:
C: Well, my point is that what we call the world is intrinsically unintelligible, apart from the existence of God. You see, I don’t believe that the infinity of the series of events — I mean a horizontal series, so to speak — if such an infinity could be proved, would be in the slightest degree relevant to the situation. If you add up chocolates you get chocolates after all and not a sheep. If you add up chocolates to infinity, you presumably get an infinite number of chocolates. So if you add up contingent beings to infinity, you still get contingent beings, not a Necessary Being. An infinite series of contingent beings will be, to my way of thinking, as unable to cause itself as one contingent being. However, you say, I think, that it is illegitimate to raise the question of what will explain the existence of any particular object.
Russell argued that Copleston was guilty of a logical fallacy – the fallacy of composition.
R: I can illustrate what seems to me your fallacy. Every man who exists has a mother, and it seems to me your argument is that therefore the human race must have a mother, but obviously the human race hasn’t a mother — that’s a different logical sphere.
To this Copleston replied,
C: Well, I can’t really see a parity. If I were saying “every object has a phenomenal cause, therefore, the whole series has a phenomenal cause,” there would be a parity; but I’m not saying that; I’m saying, every object has a phenomenal cause if you insist on the infinity of the series — but the series of phenomenal causes is an insufficient explanation of the series. Therefore, the series has not a phenomenal cause but a transcendent cause.
The crux of their disagreement was aptly captured when Russell said, “I should say that the universe is just there, and that’s all.”
For Russell the universe simply is brute face without explanation.
Copleston pointed out that this represented an impasse between them and suggested, “Shall we pass on to another issue.”
Copleston offered a significant observation on this impasse a few years later,
“If one does not wish to embark on the path which leads to the affirmation of the existence of the transfinite. If one does not wish to embark on the path which leads to the affirmation of transcendent being, however the latter may be described (if it is described at all), one has to deny the reality of the problem, and assert that things “just are” and that the existential problem in question is a pseudo-peoblem. And if one refuses even to sit down at the chess-board and make a move, one cannot, of course be checkmated…” See F.C. Copleston, Aquinas (Pelican 1955), p. 128. See also “God and Creation” in The Existence of God ed., John Hick (Macmillan 1964), pp. 86-93.
“If one refused to sit at the chess board and make a move, one cannot, of course, be checkmated.”
The refusal to engage an argument that could lead to knowledge of the existence of God by resorting to an act of linguistic veto may mask the real problem, which is that of the human heart. The human heart right from start refuses to acknowledge the slightest possibility that there might well be a necessary and absolute Being who commands allegiance from his creatures.This reminds me of Blaise Pascal when he wrote, “In faith [if I may add, in theistic arguments] there is enough light for those who want to believe and enough shadow for those who don’t.”