The Third Way is subtle and complex, and has no obvious surface similarity to the previous two, as the Second had to the First. It is couched in terms of the possible and the necessary, and thus has at least a strong verbal resemblance to another argument given for the existence of God, most famously by Leibniz. There are several points at which the argument appears extremely weak, but at which it can be defended quite well. The jump from the world to God does not take place, surprisingly enough, at the step between the possible (or contingent) and the necessary, but at a step between the derivatively necessary and the underivatively necessary. This last pair of notions, of derivative and underivative necessity, is highly obscure, as is the feature X on which the Third Way is based.
Some real things that we find have the possibility of being and not being.
But if this were the case, then there would be nothing now: since that which does not exist only begins to exist through something that does exist. Hence if nothing were in existence, it would be impossible for anything to begin existing, so nothing would now exist. This is clearly not the case.
But everything which is necessary either owes its necessity to some cause outside it, or not.
There cannot be an infinite series of necessary beings whose necessity is caused, just as, we have seen, there could not be in efficient causes.
We must suppose, then, something that is necessary in itself, which does not owe its necessity to some outside cause, but rather causes the necessity of the other things: and this is what all say is God."
The first thing which needs to be said here is that the notions of "possible" and "necessary" are here being taken in a temporal sense: they mean, roughly speaking, "having a tendency to stop existing" and "having no tendency to stop existing". This usage, curious enough to our ears, is common enough among Aristotelians. It is clear that what is necessary is always the case, is everlasting. Equally that which sometimes is and sometimes is not the case is contingent; it is "possible" in the sense of "maybe it is, maybe not". This point would be accepted quite generally. More disputable is a claim which Aristotle may sometimes make, that that which is always the case, or is everlasting, is eo ipso necessary, while that which is possible to be thus and so at some time is thus and so. Aristotle, it will be remembered, held that the world had existed from all eternity, and it may be that he held that whatever is possible is at some time realised, and that that which is always the case is necessary. What is certainly true is that Aristotle is strongly unwilling to believe that anything can just happen to be always the case: he will not recognise any contingent universal or everlasting truths.
Whether or not it is correct to attribute a belief in the Principle of Plenitude to Aristotle, there is no doubt that he quite often uses the words "possible" and "necessary" in temporal senses: that which is sometimes the case is called "possible" and that which is always the case is called "necessary". This is perhaps not as bizarre as it might seem, or at least not quite so unfamiliar. There is a strong school of modal logicians, those who deal with necessity and possibility, who insist on taking literally the language of "possible worlds" which is used to clarify certain aspects of modal discourse. That which is necessary is true in all possible worlds (or "at all possible worlds" — the jargon varies), and that which is possible is true in some possible world. That is, they in some sense maintain that that which is necessary is everywhere the case, and that which is possible is somewhere the case. The shift from expressions of time — always, sometimes — to expressions of space or quasi-space — in all possible worlds, everywhere, or in some possible world, somewhere — is not so great a change. Aristotle’s most questionable and least plausible doctrine about modality, and the apparently bizarre language which expresses it, turn out to have very close parallels in a widely-held — or at least strongly-defended — contemporary theory.
It seems undeniable that St Thomas is using Aristotle’s language here, and using modal terms in temporal senses. What is not so clear is the extent to which this implies an acceptance of any other modal views of Aristotle. Whatever we may say of Aristotle — and, as has been said, it is a disputed question — there is no doubt that St Thomas did not maintain the Principle of Plenitude. One can find it said in works on the history of modality that everyone from, say, Boethius through to Duns Scotus held the Principle of Plenitude, but this is simply a mistake. St Thomas could not have held the Principle of Plenitude simply because he did not hold an eternity of time: since for him the world had a beginning some finite time ago and is to have an end some finite time in the future, there simply is not enough time for all real possibilities to be realised. Moreover, when St Thomas speaks in propria persona about modalities, as opposed to when he is expounding Aristotle, his account is not temporal but logical.
But there is a complication which needs mentioning here. It is clear from the way the Third Way develops that St Thomas is in fact arguing from the (false) hypothesis that the world has existed for ever. The rationale for this is given very clearly in the parallel passage in the Summa contra Gentes. Aquinas thinks that if it is admitted that the world had a beginning in time, the existence of God follows immediately. The beginning of the world in time is clearly a phenomenon which demands an explanation in terms of its relation to something outside the world: and here we might all admit that "that which explains the beginning of the world" is something we all call "God". But Aquinas also believes that he has no philosophical evidence that the world did begin in time, and so he is going to grant to his atheist opponent that maybe the world has existed for ever. Even so the world is demonstrably God’s creation, claims Aquinas: he is granting to his opponent the chance to make his strongest case, since he believes that even so it can be overthrown.
I do not know quite what we should make of this. It is true that to me it seems obvious that if the world had a beginning in time, then it was made by something outside the world. Since earliest childhood, however, I have been subject to propaganda from atheist writers on cosmology who have been dinning it into me that the mere fact that, so far as we can make out, the world had its origin in a single moment a certain finite time ago, does not mean that we have to look for an explanation for that origin outside the world itself.
There are several things that need to be said here. One, against the atheist, is that I am incapable of regarding a beginning of existence as anything but a phenomenon which requires an explanation. Another, against certain theists who lay great stress on the Big Bang, is that I see no especially strong reason to hold that the Big Bang is to be identified with the moment of which the Bible says "In the beginning God created the heaven and the earth". The Big Bang is the start of the present disposition of material reality; it is the point beyond which our investigations of material reality cannot reach. I can see no reason why material reality might not have had its origin at some earlier moment. If the whole of the matter of the universe was once very very small, very very dense, and very very hot, and at a certain moment began the process of expansion and cooling in which it continues to this day, I don’t see why it might not have existed in some incalculable way for some incalculable period in its hot, small and dense state, before the initiation of its expansion, or Big Bang.
That said, I notice that the same atheist writers on cosmology who tried so hard to convince me that the Big Bang did not need an explanation were tremendously excited by the alleged rival theory of the steady state of the Universe: a theory for which there existed not the slightest evidence, but which was pursued with great enthusiasm and at great expense, merely because if you could believe in the steady state you didn’t have to believe in the Big Bang. The steady state theory has, I believe, finally been given up by its supporters; but instead I find an equally enthusiastic search for justification for the theory of the concertina-like universe. If the universe contained a good deal more matter than it does — something like ten times what it does, I believe — then we need not conclude that the Big Bang was a unique event, which seems to require an explanation, and which we might be tempted to identify with the Biblical moment of creation. Given the actual mass of the universe, as far as we know it, the universe is continually expanding and is getting gradually less and less dense and cooler and cooler. One day (though "day" is the wrong word) all the differences of heat in the universe will have been equalised, and the whole universe will be very large, very cool, and entirely static. But if there were ten times the mass in the universe that there is, there is a possibility that gravity would suffice to reverse this process at a certain point. The universe would begin to collapse in on itself again until at last it was again a very dense, very hot, very small lump, indistinguishable from the original lump from which the Big Bang started.
Well, I am told that the theory of the concertina-like Universes will not work particularly well either, because the swings of the concertina will continue to get wider and wider until in any case the mass of the universe is insufficient to bring about the re-collapse: so even if this epoch of the universe will end in a re-collapse, a new Big Bang, and thus a re-born universe, some epoch of the universe will have a definite end in the uniform coolness of 3o K. (Or maybe for that epoch, which is to come about on the last and widest swing of the concertina, the uniform temperature is supposed to be something else: I don’t know. It would be funny if it were a temperature which was capable of sustaining human life in a paradisal state. If it were discovered that the concertina universe would leave us all at the end of time in a paradisal state we might find fewer physicists keen on the theory. It would be still worse if we found ourselves obliged to believe that the final state of the universe were one in which human life were possible, but acutely uncomfortable.)
Be that as it may, what seems to me to be definitely significant is the apparently obsessive activity of some physicists in searching for what they persist in calling "the missing mass": i.e. the quantity of matter which they think would be sufficient to make the universe collapse in on itself again. Every two years or so the newspapers announce with a fanfare that the missing mass (or at least quite a lot of it) has been found. Then a few months later some of the newspapers publish a far smaller article in which it is admitted that the mass which has been discovered was rather less than had been at first thought. What never appears in the papers is an admission that within a year it has always, so far, been proven definitively that the extra mass which has been detected has turned out to be incommensurably tiny compared with what would be required to make the concertina swing. There are perhaps more things to be said on this, but they can be left for a book on the sociopsychology of the scientific-philosophical community.
I shall take it, then, that St Thomas is right, and that if the world had a beginning in time it is obvious that there is a God. I therefore also take it that he is right, in the Third Way, to presume that it had no beginning in time, and to attempt to prove that there is a God even on that hypothesis.
1. Some real things that we find have the possibility of being and not being.
2. But it is impossible that everything that exists should be such [or: it is impossible that all such things should always exist]: for that which has the possibility of not being at some time does not exist.
3. Therefore not all beings have this possibility: there must be something real which is necessary.
4. But everything which is necessary either owes its necessity to some cause outside it, or not.
5. There cannot be an infinite series of necessary beings whose necessity is caused, just as, we have seen, there could not be in efficient causes.
6. We must suppose, then, something that is necessary in itself, which does not owe its necessity to some outside cause, but rather causes the necessity of the other things: and this is what all say is God.
The first part of the notion, the idea of "possibility" or of "having a tendency to stop existing", is not too hard. It is something we observe in ourselves and in most of the things around us. The first premiss — "some real things that we find have the possibility of being and not being" — is clearly true. It scarcely needs the supporting argument St Thomas gives, that "we find some things that come into existence and cease to exist, and hence have the possibility of being and not being." The second premiss, though, is more doubtful. "But it is impossible that everything that exists should be such [or: it is impossible that all such things should always exist]: for that which has the possibility of not being at some time does not exist."
I think we should grant that that which has the possibility of not being, at some time does not exist, at least if we grant the supposition of unlimited time. But this truth does not seem to support the first part of the premiss, on either reading: "it is impossible that everything that exists should be such"; or, "it is impossible that all such things should always exist". The supporting argument which St Thomas gives does not seem to help matters. "If, then, everything had the possibility of not being, at some time there would be nothing real. But if this were the case, then there would be nothing now: since that which does not exist only begins to exist through something that does exist. Hence if nothing were in existence, it would be impossible for anything to begin existing, so nothing would now exist. This is clearly not the case."
The further claim being made here is that it cannot be that everything should be "possible" in the relevant sense, should have a tendency to stop existing: for if everything did have a tendency to stop existing, then, given infinite time, it would already have stopped, and nothing would exist now. It looks here very strongly as if St Thomas thinks he can pass from the premiss "Everything has to stop some time" to the conclusion "There is some time at which everything has to stop". This is a thoroughly dodgy move, as it stands: it appears to be a clear instance of what is called technically the "quantifier-shift fallacy", or, less technically, the "nice girls and the sailor fallacy".
The name is drawn from an obvious example. We may grant, if we like, that it is true that every nice girl loves a sailor. But we are not entitled to conclude from that premiss that there is some superlatively attractive and fortunate sailor such that every nice girl loves him. From the true premiss "Every road leads somewhere" we cannot conclude "There is somewhere — e.g. Rome — where every road leads". The fallacy is technically called the "quantifier-shift" fallacy because such words as "every" and "some" or "a" are the natural-language expressions of the universal and particular quantifiers in logical notation: and between the premisses and the alleged (fallacious) conclusions we have inverted the order of the quantifiers, i.e. we have "shifted the quantifiers". This same inversion of the quantifiers occurs when we pass from "everything stops existing at some time" to "there is some time at which everything stops existing".
It is certainly true that Aquinas’s argument here can be represented as embodying a fallacy, as being an instance of an invalid form. But, as Geach points out, if we wish to show that an argument is invalid, it is not sufficient to show that it can be represented as instantiating an invalid form. It might instantiate an invalid form and at the same time instantiate a valid form: and for an argument to be valid it is sufficient that it should instantiate a valid form. The potentially vast numbers of invalid forms which it may instantiate are completely irrelevant. As Geach goes on to point out: we can represent any valid argument as instantiating at least one invalid form. For there is nothing to stop us linking the premisses of any argument together with "ands" or other connectives, and representing the long sentence thus formed by the letter "p". Representing the conclusion of the argument by "q", we are thus able to represent any argument as a whole as instantiating the form "p, therefore q", which is about as invalid an argument form as one could wish to avoid, or to detect in the work of one’s rivals.
Clearly, though, some kind of burden of proof rests on the defender of St Thomas to show that there is some valid form which his argument instantiates; or, given that logic is far from being a complete science, to show that there is some form instantiated by this argument which can plausibly be regarded as valid. We can begin by a clarification. Aquinas does not in fact say "if everything stops existing at some time, then there is some time at which everything stops existing". Rather he says "if everything stops existing at some time, there is some time at which everything has stopped existing". The use of tenses is essential to this argument, and makes the argument at least not a pure and direct example of the quantifier-shift fallacy. A pure and direct example of the quantifier-shift fallacy would lead us to conclude (fallaciously) that there is some moment at which everything ceases to exist, zap, like that, a universal power-cut, as it were. This is not what Aquinas wishes to suggest.
Unfortunately the logic of tenses is little understood these days. It was brilliantly developed by Arthur Prior in the nineteen-sixties, but he was so far ahead of any of his contemporaries that no-one since seems to have got up to the level even of fully understanding Prior, let alone developing his work. My own understanding of tense-logic is slight, but I spent a full week once filling innumerable sheets of paper with probably ill-formed logical formulas in an attempt to work out this argument as valid. I failed, but some of the points I noticed in the process of wrestling with the logic, with the different ways of representing the present and the perfect tenses in the two versions, accurate and inaccurate, of the argument in question, made me suspect that there is a way of demonstrating the validity of Aquinas’s real conclusion here.
Another possible way out is to attend not to the form but to the content of the argument. The passage from "All the nice girls love a sailor" to "There is some sailor that all the nice girls love" is certainly fallacious, but in a suitable context — among a population containing only one sailor, for example, such as the population of the rather curious neighbourhood in which Popeye is represented as living — when the premiss is true, the conclusion will be true as well. Equally well, there may be features of the content of the argument, or of the context in which it is being made, which will enable us to pass from the premiss to the conclusion. It is arguable that if everything has a tendency to stop existing, then there is a real possibility of everything’s stopping existing. Certainly, if one claims that everything has a tendency to stop existing, one is eo ipso debarred from saying that it will never be the case that everything has stopped existing. We have seen that it is possible to attribute to Aristotle the belief that in infinite time all real possibilities will be realised; and while we cannot attribute the Principle of Plenitude to Aquinas in propria persona, it may be that he held that on the supposition of infinite time all real possibilities will be realised. This would explain Aquinas’s argument, and acquit him of the charge of having committed a gross fallacy; and the additional premisses we have provided may even be true.
But in fact we need not worry about to what extent the principle of plenitude is true, or may be true on the supposition of infinite time, or may have been held by Aquinas to be true on the supposition of infinite time. We can simply say the following: given that the world now exists, then if it never had a beginning, but has existed for ever, it must be capable of existing for ever. "X is F" entails "X can be F"; therefore, "the world has existed for ever" entails "the world is capable of having existed for ever". As the medievals would have put it, "Ab esse ad posse valet consequentia", "The inference from "is" to "can be" is a sound one". Or, in more modern terms, "P, ergo possibly P" is a theorem of any system of modal logic that aims at capturing our notions of real or logical necessity and possibility. Therefore, at least the world as a whole, and maybe also some part of it, must have a capability of existing for ever. If the world has a capability of existing for ever then it is not like, e.g. human beings who have a tendency to stop existing. Thus we have to accept the conclusion of the sub-argument, what we listed above as premiss 3: not all beings have this possibility (of ceasing to exist); there must be something real which is necessary [i.e. everlasting, having no tendency to cease existing]. We might say, more carefully: there must be at least one real thing, viz. the world itself, which has no tendency to cease existing, and is thus everlasting or "necessary" in the relevant sense.
I suppose that most people suppose that there will always be, in each of the Five Ways, some flaw, falsehood, or fallacy, and that such readers may get nervous when an apparent fallacy has been disposed of. They should not get nervous at this stage: we are very far from God. All we have arrived at is the everlastingness of the world, the fact that the world itself (and, for all I know, some parts of it) has no tendency to stop existing — given, that is, that it has in fact existed since for ever. In fact Aquinas would hold that not only the world, but also certain elements of the world are "everlasting" in this sense, the sense of not having a tendency to stop existing.
One of the elements or parts of the world which will be in this sense "everlasting" will be matter: using the word this time not in the sense given it by modern physics, but in the Aristotelian sense of the stuff of which things are made. Things cease to exist, but the matter of which they are made does not cease to exist, but becomes something else. The stuff which at one moment is a hedgehog jogging gently across the road is the next moment, after my car has passed, a flat parcel of spiky meat. The stuff which at 8.00 a.m. is nicely arranged and separate toast, butter and marmalade, by 8.30 a.m. has become a nasty mess in my stomach, and well before lunchtime has become (for the most part) part of me. The part of it which fails to become part of me within a couple of days will be part of the reason why one is foolish to go swimming off the beach at Troon. The stuff which is me, as I wander carelessly out into the desert, within a few days will be parts of vultures, hyenas, and a large number of beetles. Thus: hedgehogs cease to exist, but their matter persists. Toast, butter and marmalade cease to exist, but their matter persists. I will cease to exist, but my matter will persist: if not transformed into vultures, hyenas, and beetles, since I hope for an easier and more homely death, at least dissolved and changed into flowers and fruits with Adam and all mankind. Matter, then, is in the relevant sense everlasting: it has no tendency to stop existing.
It is for this reason that Kenny alleges that the Third Way has to do principally with material causality, explanation in the material mode, in terms of what things are made of. It is certainly true that matter is one of the everlasting things which Aquinas thinks exist, and indeed is one of the everlasting things which, if the argument he has given above is sound, he has proved to exist. But as we commented, the argument certainly proves the everlastingness of the world as a whole. That matter should turn out to be everlasting as well is no more than an extra. There seems no reason to associate the Third Way with matter in any special way.
This becomes yet clearer when we realise that for Aquinas, as for Aristotle, forms have as much right to be considered everlasting in the relevant sense as does matter. By "forms" here I mean e.g. the species of living things. Aristotle apparently thought that such species were eternal. He is usually taken to mean that as far back as you go in the everlasting history of the world you find cats having kittens, people having children, etc. It is often also alleged that he thought that it was impossible for any species to die out, but there does not seem to be sufficient evidence that he held this belief. All we can bring home to him is the belief that biological species do not have the tendency to stop existing that individuals of that species have. This is what reproduction means, and it is undeniable. Whether he thought that it was impossible for any species to come into existence is not so clear, but St Thomas definitely thought that at least one (imperfect) species had come into existence: I refer you yet again to his discussion of the question of mules. When people say, as they do, that Aristotelian conceptions of animal species are in frank contradiction to Darwinian views they are to be absolved of the charge of lying only by incurring the lesser charge of parroting falsehoods they have never bothered to check.
What is important to both Aristotle and Aquinas, and important to us in our following the Third Way, is that e.g. animal species are everlasting in the relevant sense. That is, they do not have the obvious tendency to cease existing which individuals of those species have. That, indeed, is the whole point of an animal species: it can replace itself, if not infinitely, at least indefinitely. This does not mean that it cannot be extinguished, and it does not mean that it cannot have had a beginning: what it means is that once started it might as well go on for ever, so far as we know. It may be that nowadays with our knowledge of the second law of thermodynamics we can be sure that nothing in the world will in fact go on for ever. This would naturally weaken this argument, as any proof that the world is not everlasting would weaken any argument based on the hypothesis that it is everlasting. But since it is the second law of thermodynamics which leads us to conclude not only that the world will have an end but also had a beginning, so far as we are concerned, this whole consideration returns us to the question of St Thomas’s strategy here. If the only answer to St Thomas’s arguments that even an everlasting world must be God’s creation, is that the world is not everlasting, St Thomas would take it that he has won the debate. If the world had a beginning, then it is God’s creation and there’s an end on it. As I commented, people have tried hard to convince themselves and others that the fact of the world’s having had a beginning in time does not mean that it must be God’s creation, but the effort they put into proving by whatever dubious means there are at their disposal that in fact the world did not have a beginning in time, makes their affirmations less convincing than they might like them to be.
Be that as it may, if we grant the hypothesis of the everlasting world, then we should also grant the hypothesis of the everlastingness of the species of living things, i.e. the fact that they lack the tendency to stop existing which is shown by the individuals which go to make them up. Thus the Third Way relates just as much to form and to formal causality — explanation in terms of form — as it does to material causality, explanation in terms of matter.
We now come to the step which is is aimed at getting us from the world to God, premiss four: "But everything which is necessary either owes its necessity to some cause outside it, or not." We are supposed to ask whether the everlastingness displayed by the everlasting things in the world — i.e. the world itself, matter, the species of living things, and whatever other everlasting things there may be which I have failed to notice — is an everlastingness which they possess in their own right or derivatively. This at first sight appears to be a curious question. How should we know? And what are these everlastingnesses supposed to be derivative from? To answer "derivative from God" would seem fairly obvious, but until we understand what derivativeness consists in this would be to repeat words without much sense for us. Moreover, since Aquinas is about to re-use the "we cannot go on to infinity in this line" step, which in the previous two ways related to a series of causal derivativeness within the world, it seems as if to give the answer "God" at this stage would be premature and therefore unwarranted.
I wonder whether it is, possibly, too good to be true, or at least too appropriate to be a pure coincidence; but the three examples of everlasting things which I have been able to find all allow of a fairly straightforward interpretation of the notion of "derivativeness". I assure the reader that I did not consciously choose these three examples with this in mind: the example of matter was given me by Geach and Kenny, the example of species I developed in thinking about possible objections to Kenny’s association of the Third Way with material causality, and the example of the world as a whole came to me in a flash as I was wrestling with the problem of showing clearly and briefly in a lecture that Aquinas’s earlier argument was valid, despite his apparent use of the quantifier-shift fallacy.
The everlastingness of the world as a whole is clearly derivative from the succession of its parts, in the way that the existence of any whole is derivative from the existence of its parts. The world is everlasting (ex hypothesi) not because any individual thing in the world has lasted for as long as the world has, but because it has always been the case that at least one thing has started before all the others have finished. In a similar way royal dynasty lasts for as long as it lasts because the heir has been born or at least begotten before the King has died. Matter is likewise derivative. Matter does not exist except in some form or other: the same matter is first living human flesh, then dead human flesh, then part of a vulture, but is always matter subject to some form. If the very existence of matter is derivative from the existence of the formed things which the matter goes to make up, a fortiori the everlasting existence of matter is equally derivative. The existence of species is likewise derivative from the existence of the individuals of that species: no rats, no Rattus rattus. Hence, again, a fortiori, if the existence of the species is derivative then the everlasting existence of the species is derivative.
Here it looks as if Aquinas should be objecting not to a vicious infinite regress (premiss 5, "there cannot be an infinite series of necessary beings whose necessity is caused, just as, we have seen, there could not be in efficient causes") but rather to a vicious circle. It looks as if we are saying that this or that individual can cease to exist, but this doesn’t mean that everything has to cease to exist. This is just as well, since by the earlier argument we are committed to holding that if everything did have to cease to exist, nothing would exist now, which conclusion is palpably false. No, the mere fact that individual bits of the world, or individual material entities, or individual members of species, have to cease to exist, doesn’t mean that the world as a whole, or matter in general, or the species of living things have, to cease to exist: these last three are everlasting. But when we ask why they are everlasting, we find out that they exist everlastingly — indeed, that they only exist at all — because of the existence of this or that perishable individual bit of the world, or this or that perishable individual material entity, or this or that perishable living individual of a given species.
Intuitions vary: to me this circle looks yet more vicious than any of the infinite regresses St Thomas has offered us so far. That is, it looks like even less of an explanation. It is as if I asked why a group of five Inuit is still standing on the corner after so many years, since I know that even Inuit get tired, get cold, get hungry, get bored, grow old and die. I am then told that this is not a problem: of course individuals get tired and cold and go away, etc., but the group doesn’t get tired or bored or go away or die. When I ask how this is, I am told that it is because as one individual goes away another joins the group. This, as I say, looks like a vicious circle. Moreover, it will remain a vicious circle no matter how big the circle is. Maybe the everlasting existence of the species Rattus rattus depends on the ever renewed generation of an infinite number of perishable rats. But the infinite number of the group of perishable individuals on which the everlastingness of the species depends still leaves me without an explanation: we cannot, in fact, go on to infinity in this line. As I see the argument, the vicious circle is rather tight, but St Thomas is quite right to point out that a vicious circle is still a vicious circle even when it is of infinite size. Perhaps, indeed, this is what a vicious infinite regress consists in: it is a series which, were it less than infinite, would be a vicious circle.
I think that we can safely conclude, then, that even if the world is everlasting "we must suppose something that is necessary in itself, which does not owe its necessity to some outside cause, but rather causes the necessity of the other things: and this is what all say is God." If the world is not everlasting, as apparently it isn’t, then I leave the reader to her or his intuitions. Though leaving aside that particularly vexed question, the fact that Aquinas undertakes to prove to us the existence of a God who created the world even if the world has existed for ever, makes one point which is of crucial importance in understanding the relationship between God and the world. The thesis that the world was made by God does not require that the world was made by God in time: that for some number n, God created the world 10n seconds ago. Contemporaries of St Thomas (such as Grosseteste) often cited an ancient example: if an eternal foot had been pressing eternally in the dust, there would be an eternal footprint beneath it. But though foot and footprint were equally eternal, there would be no doubt that the footprint was the effect of the foot. Equally, an eternal world, though eternal, would be the creation of, and dependent on, an eternal God.
We can go further than that. The world is not something which God once made: the world is something which God is still making: indeed, "which God is still doing" would be more accurate, as creation is more like a performance than it is like a production. The world is made by God from nothing, i.e. not out of anything. It thus has no consistency of matter to keep it in existence. As Aquinas says, "God made the world" is more like "The musician made music" than it is like "The blacksmith made a horseshoe". The horseshoe is made out of iron, and once the making is finished the iron remains. But the world is made not made out of anything, so if God stops making the world the world stops, just as when the musician stops making the music, the music stops. Despite Aquinas’s use of tags such as "we cannot go on to infinity in this line" there is no question in any of the Five Ways of our having to trace the universe back through time to its origin. Whether we continue to believe in the Big Bang or not, St Thomas’s arguments stand. Though if we turn out to be capable of convincing ourselves that there was a Big Bang but that it does not require an explanation, my own view is that no arguments, whether those of St Thomas or those of anyone else, will be able to help us very much. To what extent the Lord helps those who help themselves I am not sure: but I am sure that when those who could help themselves by thinking intelligently and resolutely refuse to do so, they have no right to expect the Lord to help them: or anyone else, for that matter.