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St Thomas Aquinas enjoys the repute of having given five proofs of God's existence, the famous ‘Five Ways’: Respondeo dicendum quod Deum esse probari potest quinque viis– I reply that you have to say that God's existence can be proved in five ways – and here they come! For students of philosophy they make their deadly, inescapable appearance in any and every manual, trotted out with a granite certainty comparable only to that with which we are assured that English Catholics once nearly succeeded in blowing up the Houses of Parliament. Here, however, our concern is with St Thomas's teaching method, rather than with a readers' consensus about what he said, that of a readership largely content to ignore the question: and this article is an endeavour, not indeed to ‘flog a dead horse’, but simply to explain the pedagogy implicit in the great Summa. That simply means, how to read it with as much ease and understanding as its author intended – and indeed indicated from his opening sentence onwards. The article ends by mentioning some highly regrettable consequences of the neglect, briefly updating (if the paradox be allowed) the post-Tridentine moral tradition, by adding to it from St Thomas's nowadays largely forgotten legacy.


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The ‘Five Ways’ are truly the tip of the iceberg: but we must start somewhere; and the basic question of whether we shall be theists or atheists is, of all other passages, the one we can usually expect to find the most dog-eared and well-thumbed. For that very reason we should be wary of starting there – and start instead, only a few pages earlier, at the very beginning.

On reading the very first sentence of the Prologue, then, we encounter a nuance easily overlooked. For he says,

propositum nostrae intentionis in hoc opere est, ea quae ad christianam religionem pertinent, eo modo tradere secundum quod congruit ad eruditionem incipientium,

… our endeavour here is to hand on what belongs to the Christian religion in a manner suitable for teaching beginners (my italics).

Though this has usually been taken to mean that he is writing for beginners,1 and all the more so for his having just before that quoted St Paul's metaphor about milk for babes (1 Cor.3:1), that is not what he says. And when insistently taken to be what he means that view flatly contradicts his very opening words, saying why he is adopting that stance: ‘Because it is the teacher's business to instruct not only advanced pupils but also beginners in the Catholic faith’, non solum provectos … sed … etiam incipientes. The point may need stressing. In three steps, then,

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    He begins thus, as above: Quia catholicae veritatis doctor non solum provectos debet instruere, sed ad eum pertinet etiam incipientes erudire…, so indicating that both classes are being addressed - ‘advanced pupils, don't go away!’
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    Then he adds the parenthesis which seems to have misled so many: …(secundum illud Apostoli 1 ad Corinth. 3,1: Tanquam parvuli in Christo, lac vobis potum dedi, non escam): (for as St Paul said, … I fed you milk, not solid food, as [you were] Christ's little ones). And finally
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    where we began: ‘our endeavour here is …a manner suitable for teaching beginners’ - and certainly not, therefore, matter which may be all that beginners can be expected to understand.

But a further argument against the common assumption, about beginners only, is the implication of the nuance; for the manner-suitable-for-teaching-beginners surely invites the question, are the ‘beginners’ really there? Well, only in the abstract, surely, to be kept in mind by the attentive reader. After all, the latter is evidently not being addressed as if he were the beginner. Quite on the contrary, going by the things he is about to be told his status is that of someone eavesdropping on the instruction of someone else, a third party who really may be a beginner, though not even that much is strictly implied. Once again, it is the manner that is going to be simple, the pedagogy, and not the matter; not the content of the exposition, but the way it is going to be presented. What St Thomas is trying to avoid, he then says (mentioning no names, of course.), is the confusion often generated by writers posing too many pointless questions, putting them in the wrong order, or making useless repetitions. He pledges his best endeavours to that end, by the help of divine providence, and so saying he launches his ship, leaving the reader to set sail, take his bearings, and move ahead, with due circumspection.

Taking him at his word we read on and find the great Summa to be presented in a rigorously maintained format for each of the topics discussed, interspersed where need be with terse introductions, like the very first one just described, to the group of ‘questions’ (quaestiones, topics) about to start. Each such topic is treated as a group of ‘articles’, each one, an articulum, bearing as its heading what really is a question, e.g. Does God's existence need to be proved? … can it be proved? … is it true anyway? (ST 1 2.1, 2, 3.) The great Summa, then, is presented as a quiz with explanations. Moreover, where others refer, say, to Ia-IIae q.II a. I, II, III [prima secundae, quaestio secunda, articulum primum, secundum, tertium] we can simplify (as we just did) by writing ST 1-2 2.1, 2, 3, meaning the first, second, and third questions raised about the 2nd topic: and so on, generally. The questions then posed, starting each articulum, make up what is nowadays called a ‘multiple-choice test’, but with only two choices at each stage – Yes or No – and explanatory details added on a set pattern, to be kept in mind. The answer and supporting exposition then come in five rigorously maintained stages, making up the six in all, familiar to his readers.

Familiar though all this is to connoisseurs, we do well to avoid any shade of the contempt that proverbially follows on familiarity. The rigour itself should warn us against selecting quotations in isolation from the rest of the argument, as one picks trains out of a railway timetable. Doing that can be expected to falsify his precise meaning, and often seems to do so. In fact making the best use one can of what he has to say surely depends vitally on perceiving the relative importance of each of the stages, according to the author's own evident intention. They are these –

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    a question, ‘whether or not’ [the proposition then stated – say ‘God can be proved to exist’] is true, Yes or No;
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    cogent arguments (the objections) giving the wrong answer, No for Yes, Yes for No;
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    a manifestly stronger argument in the opposite sense, introduced by the words Sed contra, ‘But on the other hand’, decisively toppling all the objections at one fell swoop and thereby turning the course of the entire argument, giving the right answer and embodying a manifest reason why;
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    a conclusion, qualifying or restating more deliberately the thought just expressed;
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    corpus articuli (body of the article, topic discussed), general comments; and finally
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    replies to, or special points regarding, the objections.

Now while we are not short of advice on how to read the Summa some writers recommend pausing at each objection and trying to answer it. If followed too closely, that procedure is likely to make the reader give up in frustration quite soon: for they are good objections and sometimes quite numerous. Surely the real point of the objections is to show how the Sed contra is a stronger, better argument than any of them. It immediately carries conviction, sweeping all before it. Moreover it convinces by its rational, logical force simply as an argument independently of any other consideration, even its origin. It is necessary to stress this: for though the Sed contra is often a quotation from sacred scripture or the Fathers or canon law – in a word, from authority (sometimes, indeed, that word expressly, ‘the authority of sacred scripture’ etc) – its being that is, at this initial phase of the argument, less important than the reader's seeing clearly that what it says truly answers all the objections, no matter where it came from. The writer is persuading the reader, not waving a big stick, saying ‘you'd better believe this!’. There is simply no question of believing anything – apart from its being a good argument, better than the objections, and therefore the truth.

For that very reason anyone concerned to persevere right through the book has a guide, just there, to easy reading, or easier at any rate, by and large. Carefully observe each time how the Sed contra answers the question, and everything else is detail. For some of it is minor detail altogether and can hold one back endlessly. With a little care you find that there is really no doubt about it. Where it exists (though sometimes – very rarely – it is missing, or is reduplicated), stage 3, Sed contra, is almost invariably seen to be the main point, though not of course the only one: and its being so can hardly be an accident, but must have been the author's deliberate intention – indeed, the manner of exposition suitable for beginners already promised at the outset. Moreover, when his friend and alter ego Friar Reginald of Priverno took over the writing, left memorably unfinished two years before St Thomas died, in completing it afterwards with his Supplement he adopted exactly the same manner of presentation, where the same rule applies, making the Supplement likewise easy to read.


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We can now illustrate all this by considering in detail the second topic of them all, the question of God's existence – or, if you prefer –, non-existence. The absence of bias is quite striking, as has often been said. St Thomas was the greatest rationalist of them all: and for good reason – another paradox – since he was observed by friends (who saw some of it happen2) to be a Christian mystic as well. Could anyone who really was, be much interested in logical demonstration that the God who allowed him (like Moses) to come so close was not a chimaera, but truly there? His most vital words on the subject (ST 1 2.3, Utrum Deus sit, whether God exists anyway) - the Sed contra - were those that readers of the Bible find God speaking of himself, when asked his ‘name’ by Moses, Exod. 3:14, a question which meant, what is it that makes him God, so to speak, what is his special feature. His answer is often rendered in English as a manifest tautology (I am who I am, I am he who is etc): but it does not really defy translation, being tantamount to saying ‘I am he who will always have been there’, ayeh asher ayeh, the Hebrew imperfect serving conveniently for future also. (Hence Jhwh, he who really can say that, understood as he alone who, having always been there, strictly qualifies as the one who causes everything else to exist.)

Now for our understanding of the Summa it is important to note two things, the first being that Aristotle was later on track of the same thought himself: an elaboration of the idea of cause to explain bare existence itself, the existence of anything at all. Secondly, by the time St Thomas was writing the great Summa he had already read the accurate Latin translations of Aristotle made for him by William of Moerbecke3 and had himself observed the similarity of thought. Aristotle's cogent theorizing presumably explains why St Thomas almost always (with one interesting exception, to follow), refers to him simply as Philosophus, ‘The Philosopher’, as though he were the only one who counted. His crucial remark in the Metaphysics, 10:7, that ‘there's one more! [epistémé, discipline, science, area of inquiry so far untouched – by all of us]’, though found in translations, presumably, is not included in any anthology of Greek philosophical writing that I know of; nor does it seem to have been singled out for mention by Ross or Jaeger. If we take the whole passage - down to 1064a36, ‘I mean something existing [arkhé, a principle/origin/beginning] quite apart [from the world] and unchanging’, lego de khôristé kai akinétos - it poses problems for the translator. But the central thought itself is surely clear enough.

(1063b37–1064a4) Every science or discipline [he says] looks for principles and causes, governing each of the matters to be explained by it; thus e.g. medicine, gymnastics, and all the other practical and theoretical sciences. For each one of those disciplines is concerned with some object of study as already determined in itself and already there, in existence, though [it is] not [concerned] with why so, why the object should already exist. But there is [therefore – there needs to be!] yet one more science, another discipline besides and apart from all those … (1064a28) Since there is, then, a science of being as being, of existence as such [postulating the cause of it and all], a science or discipline quite separate and distinct from those others, we have to consider whether or not it [‘metaphysics’] is to be reckoned along with the natural sciences …

And then the answer: it is not. The reason why not is that the question just posed is more fundamental than any other imaginable, clearly: why there should be anything at all (even a tiny particle of dust if that had been the entire universe) rather than nothing at all. What is it that accounts even for that much – for existence itself?

Though Aristotle does not gloss in that kind of way he does say, vitally, epistémé tou ontos hôs on, a science of being as being: a discipline or effort at understanding, and consisting basically, like every other, of a study of causes, of reasons in the concrete. What he says here instead is that the natural sciences deal with what is subject to change (peri ta kinéseôs ekhont' arkhén) [and hence do not qualify as the explanation sought here]; and the theoretical sciences – mathematics, logic, rhetoric, …– deal with what is permanent but not apart from the world. (Though abstract they still relate closely to it.) Aristotle's postulate, to explain why there is anything at all rather than nothing, does not change; and being ex hypothesi the most permanent thing there is, it exists apart from the world.

The passage just considered is not to be found, then, in Ritter & Preller, Kirk & Raven or in Henry Jackson's Texts, 1901–1914;4 and it is nowhere (that I can find) mentioned by Ross or Jaeger.

The reason for the devaluation and neglect of Aristotle's argument may perhaps lie in the digression that immediately follows, where he turns, straight after his rational, metaphysical ‘break-through’, to fanciful cosmology and the question how many ‘prime movers’ to posit. From riding two horses at once, then, he comes a cropper, so delighting the sceptics with his dotty speculation about whether we should say 47 or 55, and why. But then, arguments usually consist of separate steps; and some of them, notably those at the end, may be less vital than the others and can for good reason be edited out. Despite Bertrand Russell's advice (in his History)5 that Aristotle's argument ‘proves the existence’ of so many prime movers (and therefore nothing at all), we need not doubt that Russell himself understood that editing principle just as well as the rest of us. Aristotle likewise. But before committing this indiscretion Aristotle delivers some interesting obiter dicta: first, saying that those who follow the argument thus far but won't make the needful postulate break off the discussion instead and stop all conversation. (Had he tried it out at ‘seminars’– and found that some of them wouldn't buy it?) The second obiter dictum is really a group of qualities, familiar to enthusiasts for the ‘Five Ways’:

(1072a19) Since this is a possible account of the subject and if it were untrue the world would have originated out of nothing [contrary to the axiom that nothing does, which he has already mentioned, (1062b24–26)], the difficulties [about change] are now resolved … There is an unmoved mover (‘move’, kinein, meaning ‘change’–‘locomotion, I move’ being indicated in Aristotle by phora, pheromai). It is eternal, a reality, actual … [and later on (1072b14] a mind, nous. This prime mover, then, exists of necessity … On such a principle the heavens and the world depend.

Compare that with St Thomas's Conclusion (stage 4, ST 1 2.3 conc.) just preceding The Five Ways, about ‘one primary being, unchangeable, first cause, necessary and not contingent on anything else, highest (infinite) in positive perfections, and master-mind’… and, even if not a perfect fit, the resemblance is surely striking. But what is even more striking is their position, placed by both writers – Aristotle and Aquinas –after the main point has been made, as obiter dicta: that is to say, as ways of viewing, or reviewing, the result - and not, ways of proving it.

Not but what Jacques Maritain thought otherwise. He appears to have believed that assertions made by Pius X and Pius XI about St Thomas's arguments (for God's existence) being ‘the most cogent of all such arguments’ have made it obligatory on Catholic believers to regard his ‘Five Ways’ as rigorous proofs of God's existence, on pain of being suspect – as he said in a footnote – of modernism. (‘… if the truth is to be told’, he added: and why not, indeed?).6 For him they were arguments you are obliged to accept as valid, 1. even if you already, like St Thomas's pupils and readers for whom he wrote the great Summa, accept the foregone, in fact by then already established, conclusion (‘God exists’) and don't need further convincing; and 2. even, so it appears, if you have to bang your head up against a brick wall to make yourself believe they are valid, each of them separately and from a standing start. Maritain's failure to see the implication of what he was saying becomes easier to understand when you realize that he may perhaps have borne a grudge against people whom he couldn't convince. Small wonder that a writer like Richard Dawkins (who likewise ‘takes no prisoners’, as a critic said) could target theism, in his book The God Delusion, as a point of view resting on arguments such as those insisted on by Maritain and successfully fathered on St Thomas.

What is required of a Catholic believer is his assent to the truth of propositions - and of course the right ones - which he should therefore make an effort to understand, if he wishes to remain a believer. But the mental journey the mind makes, called an ‘argument’, from one proposition or more, called ‘premisses’, to another - called a ‘conclusion’ - now surely that is rather different. Does the Catholic Church require its adult members to accept the validity of arguments also?

Many people seem to think so, believers as well as unbelievers, but carefully considered that surely proves not to be true. How could it be? I believe facts and testimonies: notably, all the things my mother told me about her early life and afterwards - because I knew, then as now, that she was a truthful person and a reliable witness. In much the same way, having come to believe at 23 that the teachings of the Catholic Church might well be true I got priests to instruct me and became convinced that they were. But my accepting them ever since, along with my readiness to accept others, is nothing like leaving my thinking to the Church. How could that be expected of anyone, believer or no? Though you might not think so, going by what neo-modernists and other heroic individualists think, over teachings we believers may find hard to accept here and now as articles of faith we Catholics are obliged to convince ourselves, when others have failed to do so, and not to expect others to render the service - and if we can't, not to give up trying.

As an Anglican at 23 I found the dogma of Our Lady's Assumption hard to accept but at 61 finally realized that the complementary dogma (still not defined!), that it is not to be found in sacred scripture, is demonstrably false. For the Bodily Assumption is surely implied by the very last anecdote in the Gospel record, John 21:20–24 - just where you might have expected to find it. There, Christ hints to Peter that he will be coming back for John, though Peter will be dead by then, a martyr. And indeed he was. But come back when– and why? The belief that the end of time (the Parousia) was meant – and therefore that John would never die – is rejected, despite the commentators: and the hint is meticulously repeated, nine words of Greek, so as to ensure the accuracy of the Gospel record, so transmitted. But then, if not at the end of time (with John still there, only sleeping in his grave, as many came to believe), when? The only alternative is that Christ meant that he would be coming back for his Mother, whom he had expressly entrusted to John's care already, just before he died, Jn 19:27. ‘And from that hour’ they lived at the same address. So it says. No matter what else he may have meant, then, it was clearly a coded message about a family matter, to remain secret until the early Church had matured. Has it still not done so? What a pity if that were the sober truth.

Arguments are there to persuade, not to coerce. Mental, intellectual coercion is a contradiction in terms, given the autonomy of our thinking, and would be an affront to reason itself, shared objectively with others, though only on condition that we and nobody else exercize our use of it. On the other hand, philosophers like J.S.Mill who claim the right to follow their reason ‘no matter where it may lead’ them seem to overlook two possibilities. One is that it may lead them to undesirable behaviour; and another, less objectionable, is that it may lead them (as my own thinking sometimes does) back to where they started - in other words, in a circle. Over questions of law, medicine, aeronautics, and so forth, it would normally be unwise not to trust those who really know: and people therefore adopt a judicious measure of compromise, a golden mean somewhere between respecting proper authority and thinking for themselves.

The dogma defined at Vatican I (Denz.1806), that God's existence as creator of the world (the universe) can be known for certain by man's reason alone and of itself, unaided by divine revelation, is a proposition about the power of your mind, such as we all have shortly after infancy. Because St Thomas showed (ST 2-2 1.4-5) why the same truth cannot be at once an object of faith and of reason (depending logically on –and yet– independent of, divine revelation), Dr Ludwig Ott was certainly wrong in his assertion, made in his book on Catholic dogma,7 that the Vatican definition made of God's existence an object both of faith and of reason. No assertion can be that. The truths of the faith one believes, if at all, on the testimony of the Church (rather like my believing, on my mother's testimony alone, her reports of the world of her youth – about the music halls, the Zeppelins noisily bombing the house opposite, and alas for her hearing!). But for truths of reason, if simple enough (as God's existence is, sole cause of all other existence), your own reason suffices – and it is a mistake to use anyone else's too slavishly. The anti-modernist oath, Denz. 2145, once obligatory on priests, contained words about holding God's existence to be knowable for sure ‘and what is more, demonstrable’ (certo cognosci, adeoque demonstrari etiam posse, profiteor) by the light of reason: a phrase which some people, Maritain presumably among them, took as a recommendation of the Five Ways and other formal ‘proofs’ of the same proposition. But those who express their conviction by simply saying, ‘If God didn't exist the world wouldn't exist either’ are merely summarizing Aristotle, an invaluable witness to the rationality of the thought. For him it was a postulate, rendered necessary by rational argument: and because necessary, a logical conclusion.


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Anyone wishing to object that none of that takes account of Hume and Kant's criticism of causality can take consolation from St Thomas's rarely mentioned anticipation of such lines of argument and indeed from Cicero's famous remark also that intellectuality and pseudo-intellectuality go together. There is nothing you can say which is so absurd, Nihil tam absurde dici potest (he said) that some or other philosopher hasn't already said it, quod non dicatur ab aliquo philosophorum.8

Having lived and died long before David Hume tried to debunk the very idea of cause-and-effect, Cicero was unable to quote the best instance of them all, in illustration. Though for most people it's futility on stilts, ackowledged experts were still finding it credible quite recently. Historians, doctors, plumbers, roofers, and other professionals often talk about cause-and-effect, meaning reasons for what is there, or for what happened - reasons in the concrete. We all think like that. But why we think like that, is surely of no great interest. Is it a question at all? Isn't that just what ‘thinking’ means, or most of it anyway? - asking why it happened, or what caused it?

Nevertheless Hume's arguments were intended to show that cause and effect never have a bearing objectively, out there, which we can justify, but depend instead on an imaginary connection (subjectively, in our minds) which we have got used to assuming to be necessary, virtually a synonym of ‘true’ for him and his disciples. We imagine (‘fancy’, in Humespeak), so he says, that even if for the first time as adults – just put there, fully compos, no history – we saw two billiard balls colliding, then we would still see the allegedly causal connection, the moving one ‘causing’ the one at rest to move. We'd guess, he meant: so we imagine. Despite the hypothetical nature of the argument, through and through, it seems to have convinced some people and is still being trotted out, as knowledge obligatory on philosophy students preparing for examinations.

In view of Cicero's remark and my claim that this famous paragraph of Hume's illustrates it, Hume's actual words should be quoted, if only in translation.9

We imagine [he said, and I translate] that if we came instantaneously, ready-made into this world, we could immediately have inferred that one billiard ball would set another in motion on impact, and that we need not have awaited the outcome to be quite sure of it. We are so influenced by habit that, where it is most deeply ingrained in us, it not only makes up for our ignorance but hides itself also and seems to have no place, to play no role, simply because it is habit and it is deeply ingrained.

But isn't Hume's supposition self-contradictory? How old is the observer, with whom we are invited to change places, just arrived and ready to guess? Why is he ready to guess? And if so, what is his history? If it were a case of conscience, the mysterious stranger's, you would have to ask all those questions, to understand and deal with what Hume is alleging about him and his thinking, despite the breezy, arrogant assumption that he has made himself clear. Moreover, he is surely trying to correct an error that doesn't exist: that given what we take for a cause you can't guess the effect. But who said you could? Later on, in Part 1 section V, he nevertheless gives further instances, as though he has not already made his point, as far as it goes. Magnets attract, gunpowder explodes, milk or bread nourish men but not lions or tigers – but you wouldn't have known, without something he calls (though never defines) ‘experience’. Now all that may be true, of people who don't already know and can only guess. But it certainly puts the very idea of causality – most people's idea – back to front. Without prompting from Hume and his kind, the rest of us spend our time looking for causes, not trying to guess effects: and the process of successfully finding the cause, the reason in the concrete, is the same as that of finding the truth – simply because an untrue ‘reason’ is not a reason at all.

None of that seems to have occurred to an Oxford professional, evidently convinced of the soundness of Hume's arguments, who said this:

… about causality … Locke [he says] never saw the problem. But Hume did, and his thesis that the idea of necessary connection, which he saw to be the essential element in the notion of cause, was an impression of the imagination came as near as it could, without actually getting there, to Kant's thesis that it was a formal category of experience.10

Well, life is not a dream: and on waking we find – all of us – a world governed largely by cause and effect. Cicero's warning was still vitally needed in 1973.

For his part, Kant acknowledged his debt to Hume with a memorably back-handed compliment: ‘… the most intellectual of all sceptics and the most influential … it is well worth the trouble to present the route Hume takes to his conclusions and the errors of such a perceptive and admirable thinker, for their having put me even so on the track of the truth, and indeed for any relevance they might have to my purpose.’ (Charming modesty.)11 But their rowdy slogan, Hume and Kant together – that all knowledge comes from experience– was never recollected in tranquillity. It was too flawed to be really a Copernican revolution, but it may well have originated as a protest against any theory of innate ideas, such as that indicated by Plato and others, who may really have believed (some of them) in the transmigration of souls, despite Socrates and his closing speech. Transmigration, also called metempsychosis, was meant to explain why and how babies are born with minds, and with thoughts in their tiny heads. Hume and Kant overreacted, implying that they came with no baggage and no pre-natal human, rational ‘experience’. But quite obviously they did: and that was settled beyond cavil when it was maintained that babies being aborted didn't feel pain – and irrefutable evidence was then produced to the contrary.

Taking note of such more recent history we do well to recall the fiercely dogmatic opening sentence of Kant's Critique of Pure Reason, the Kritik der Reinen Vernunft (or KRV). ‘That all our knowledge comes from experience’, he says, ‘there can be no doubt’. Surely that justifies a right to expect a clear, intelligible definition of ‘experience’, before we take the dogma any further. Well, the definitions of terms given at the end of later editions of the KRV are the work of his editors (or so one must assume, without any page references to Kant's own words): and they are not very informative. But near the end, he finally lets the cat out of the bag himself by telling us that ‘experience’ means a ‘synthesis of the perceptions which supplements my concept, which I have through a perception, by others in addition’.12 Quite so: and who could say otherwise? But what does all that mean? And is it really worth my trying to find out?

Kant's philosophy has inevitably been more widely read and lovingly pondered over in the German-speaking world than elsewhere. Even as I write this, in fact (life being full of surprises), his writings are being used as a TV script, on BR Alpha (Bayrischer Rundfunk TV), in an already long-running series, 2006–8, called ‘Kant und Sophie’. In it, a bewigged Kant, period costume and all, makes sudden appearances to a pretty philosophy student, played by Ann Kristin Leo, who applies his teachings to her life, her love affairs, and so forth, from time to time repeating them word for word to his evident pleasure, contradictions in terms notwithstanding - such as leere Zeit13 (empty time, without matter, time ticking away though nothing there to do the ticking). But now Aristotle's definition of time, meaning duration, as measurement of change, before and afterwards, can be found in all the relevant Oxford texts, by consulting the index, s.v. chronos. That means, the sun moving across the sky to mark the days for us, or across a sundial marking the hours, water running through a clock so constructed and calibrated, to which one can add modern devices rendered possible by clockwork, electronic vibrations, etc. But all that is material change, unlike you changing your mind, and requires a material universe already existing, in which alone we can ‘tell the time’– and that only by referring to matter in some way, our purely mental guesses normally being most inaccurate.

Despite all the adulation, Kant's main bequest has been the unanswerable question whether he was an idealist, ontologically, or a realist. Learned opinion is clearly identifiable, it appears, for each writer listed, as one or the other – and located accordingly in bibliographies.14 There, they are about evenly divided on the point, half thinking he was a realist, and the other half an idealist: but nobody knows. Those who find it worthwhile presumably gravitate to a compromise, though not of course to a reconciliation. That is a logical impossibility, given the incoherence, the ambiguity, and the pervasive obscurity.

Now what Hume said about cause-and-effect, later taken over and adapted by Kant, had already been anticipated and subsumed, in fact, along with something he and Kant both omitted to say, by a succinct paragraph in the great Summa of St Thomas, just before the Five Ways. But alas, its force and relevance seem to have been ignored (as far as I can make out) by all those hundreds of writers who have commented on Hume, Kant, Aquinas, and the question which all three of them had in mind, those two wishing to say No, St Thomas to say Yes. It was, whether you can infer God's existence from that of the world, as a refined sort of cause or otherwise. St Paul said you could – and that people always have done, Rom. 1:20. And St Thomas agreed but, always the critic, considered three objections to your being able to say Yes. They are that: 1. it's an article of faith, the first in the Creed (I believe in One God), and therefore, like all other articles of faith, is strictly above reason; 2. some say that all we know of God is what he is not; and then 3. there would have to be some proportion between the supposed infinite cause and its finite effects, which there hardly can be. He then quotes St Paul as above, saying that what we can't see we can nevertheless infer and in that sense perceive, through the things he has made. In the general discussion following, the corpus articuli, he then says this (ST 1 2.2 c.: Utrum Deum esse sit demonstrabile, whether it can be proved that God exists):

… demonstration is of two kinds. One, from cause to effect, is called [in Latin] demonstratio propter quid (what it causes) and is from prior knowledge simply [what you already know about the cause]. The other is from effects and is called demonstratio quia (what causes it); and this starts from what is the most evident to us, because when some effect is more manifest than its cause, we start [arguing] from the effect. From effects their cause can be proved to exist precisely because the effects, [though] better known than their cause, depend for their very existence and reality on a cause: and hence given the existing effects, the cause itself must also exist [i.e., is thereby demonstrated to exist].15

Causal inference, then, can work two ways and mean two different things. From a concert pianist we normally expect some sort of piano recital: demonstratio propter quid, what it [or he] causes, our musician at work. (No doubt policemen often think rather like that, of people they already know about: and which one could have done it, being the way he is and having the opportunity?) But for most of us, causal inference is usually the other way round: what caused it? Straight off, no idea: but then you investigate … From the puddle on the floor … to the hole in the roof … and so on, demonstratio quia.

On the other hand, Hume began by limiting causality to guessing effects not already known, demonstratio propter quid– but in each case, then, without the prior knowledge which alone could have validitated the inference. You certainly couldn't guess, and you don't imagine or ‘fancy’ that you could guess, that the stationary billiard ball would move on impact, unless you'd already seen something like it (a datum very cleverly called ‘experience’); or that magnets attract, gunpowder explodes, etc. Hence Locke, as we were assured by the Oxford professional, could not see the ‘problem’– not having stymied himself in the first place, as Hume did.16 And Hume went on to make it worse by ignoring altogether the commoner sort of inference, demonstratio quia, and not asking the right question – simply ‘what causes it’, the one we all ask, often enough several times a day, mostly finding the right answer. Even so Kant seems to have found Hume's words a good starting point for querying the objective validity of any kind of causal inference whatever, though as usual he gave no examples, to illustrate how his thinking could apply to the world we all share. All of which surely indicates that Hume and Kant closed their eyes to half of the truth and thereby failed to refute the commonsense notion of causality, elaborated for us by Aristotle and applied by St Thomas.

Here, then, are five arguments (five other ways!), intended to persuade the reader that, despite appearances and indeed despite the virtually unanimous opinion to the contrary,17 the Five Ways of St Thomas (ST 1 2.3 corp.) were never meant to be understood as rigorous proofs of God's existence to a reader who had not already been convinced. They are listed in order of importance, as it appears to me.

  • 1
    The assumption that they were intended as rigorous demonstrations ignores altogether St Thomas's pedagogy in the great Summa, where the simplicity of method pledged in his opening sentence (carefully read) soon leads the reader naturally to the conviction that what he himself evidently regards as his strongest argument occurs almost invariably in the Sed contra, despite the corpus articuli, which is usually general discussion of the point already made in reply to the question posed initially. Moreover, though the Conclusion, at stage 4, Necesse est inveniri in rerum natura unum primum ens &c (There is bound to be at work in nature a primary being …), may look like what is meant to be a deduction from the Sed contra, it can also be read as an exercise for the reader (‘What you now have to do is …’), to ponder the nature of the First Cause – the details to follow being five ways of doing so, on the lines of Aristotle's obiter dicta about the already demonstrated Prime Mover.
  • 2
    The word probare (‘prove’) is not a synonym of demonstrare (‘demonstrate’), in Cicero and much later. Arguably it never was, as in highly stylized English is still is not.18 When Cicero says ‘Adsunt enim, qui haec non probent19 he means, ‘There are people who don't believe that’– in evidence, then, that for Cicero probare means someting quite different from what we mean by ‘prove’– more like accept, believe, ‘swallow’, ‘buy’…, even ‘verify’, … . Hence great caution is needed when explaining those words Respondeo dicendum quod (I reply that you have to say that …) Deum esse quique viis probare potest' (… God's existence can be rendered more intelligible in five ways – or some such phrase).
  • 3
    An unmistakably clear indication of how St Thomas himself viewed the Five Ways occurs at ST 2-2 1.8 obj. 1, already mentioned, where, discussing the first article of the Creed, ‘I believe in One God’, he queries whether you need to believe what you can in fact prove; since you can't do both, for one and the same proposition (ST 2-2 1.4, 5). He then explains, at stage 6, in the replies to objections, that the belief expressed is in the Holy Trinity, not in God's existence. But to clarify the objection itself he has already mentioned that ‘Aristotle and many others’ (naming him for once) gave proofs of God's existence. And so saying, despite his invariable practice of referring back to points aleady established, he does not mention ‘Five Ways’, as though he had ever claimed that they were ‘proofs’. Even on his own testimony, then, not guilty as charged.
  • 4
    Because St Thomas was not an inspired writer, in the theological sense (though surely so in almost every other), the authority to rule on thomistic exegesis does not belong to the Holy See or indeed to anyone else, not being per se a matter of faith or morals, merely a question of what he himself meant (and even independently of what the Holy Spirit inspiring him may very well have meant, here and there, though presumably nobody knows). Furthermore, though the Popes said ‘arguments’, they did not say how many: a point allowed to pass without comment, by Maritain. Their aim was doubtless to recommend the faithful to ponder what he said on the subject: all of it.
  • 5
    Competent philosophers concerned to show the arguments to be rigorously conclusive, despite all, openly acknowledge the difficulty of vindicating the claim but do their best, often admirably so, to solve the problems of interpretation consequent on ignoring St Thomas's pedagogy. Thus e.g. Fr. Edward Sillem (once a seminary professor at Wonersh, Guildford), in his book on the Five Ways.20 Conversely, publicists hardly of the first rank have no difficulty in showing that the Five Ways prove nothing, apart from St Thomas's being curiously naïve on a central question. It goes without saying that the hardest people to convince that the Five Ways were not meant to be rigorous proofs, anyway, can be expected to be those who have published books based on that naïve assumption.


  1. Top of page
  2. Abstract
  3. 1
  4. 2
  5. 3
  6. 4

Surely our understanding of the Catholic moral tradition, comprising natural-law casuistry in particular and moral values in general, is now open to question also: and indeed as expressed in the seminary manuals, in one respect far more urgently so than in any other. For if we ask, what makes a sin a sin, the idea we all have – about doing somebody harm – is not the definition you find in the moral theology manuals. There, sin is defined dogmatically, as ‘breaking God's law’, an idea hardly applicable as a criterion for diagnosing it. In contrast Christ's own summary of the entire moral law –‘all the law and the prophets’ (Matthew 7:12) – as ‘doing as you would be done by’ gives a practical rule of thumb which connotes a potential victim, as soon as you ask, ‘doing to whom?’.

Asking why fornication, in particular, is a sin, St Thomas expressly rejected as inadequate the ‘breaking God's law’ argument, in the Summa Contra Gentiles (3:122), saying that God forbids us nothing which is not against our own good, meaning ‘each other's good’ as well:

Non enim Deus a nobis offenditur nisi ex eo quod contra nostrum bonum agimus.

And that includes eminently the child liable to be created by the act of fornication, the vagus concubitus (‘sleeping around’), whose future well-being is put in doubt, generally beyond cavil, because the parents-to-be are not married. In the great Summa, ST 1-2 71.4c., the argument has developed to the one just mentioned, about mortal sin meaning opposition to charity, victimising somebody.

Quodlibet enim peccatum mortale contrariatur charitati …

And, most basically of all, setting aside St Thomas and even the Sermon on the Mount, a Christian of any persuasion, aware that ‘God is love’ (1 John 4:8 & 16), already has the assurance that ‘God's law’ is truly the law of love, the logical criterion for breaking the law therefore being victimisation.

Such ideas provide a natural way of diagnosing sin, objectively speaking, and saying what makes a human act a sin – the deed in itself, whether or not the mind and heart behind it. That no such practical advice was available from the manuals, long in advance of the great row over contraception in the years following July 1968, is to be deeply regretted. They all made it a matter of dogma instead. To mention just one consequence out of many, the moral liceity per se of ‘natural family planning’ has remained for some people an arcane mystery altogether, even though everyone knows that during the infertile (‘safe’) period of the menstrual cycle there is ex hypothesi going to be no victim anyway, to be denied his only chance of ever existing.21

My claim that it is the neglect of St Thomas which has left serious gaps in the post-Tridentine moral tradition can be vindicated with surprising ease, and (for this writer) a certain nostalgia. For the attitude to the corpus of moral theology taught to seminarians during the three centuries before Vatican II was well summed up by the English Jesuit moralist Fr Henry Davis, who taught at Heythrop College, near Chipping Norton, in Oxfordshire. (He died there on 4th January 1952: and his portrait in oils still smiled benignly down on us in 1964, from just above the lecturer's seat.) Far from acknowledging any possibility of chinks in the armour, or good ideas lurking all unused in St Thomas, he put his trust in far lesser mortals instead. (‘Vermeersch, Cappello, Prümmer, Aertnys-Damen, Wouters, Merkelbach, Ayrinhac [for canon law], Génicot-Salsmans, Lehmkuhl, Ferreres and Noldin.’) And presumably for just that reason he expressed his loyalty to them in an admonition of astonishing frostiness, in the Preface to his four volumes on moral and pastoral theology,22 signing them off in 1934.

A writer on Moral Theology today [he said] must be indebted beyond measure to the labour of past writers, for the matter is one that has been treated with the greatest acumen and scholarship during well-nigh three centuries, and there is no room for originality. (My italics.)

He further acknowledged his special debt to ‘the modern workers in this field’, exemplified by naming those just listed: all of them writing, then, since 1634. But in saying all that, he unwittingly implied that none of them took any account of a document, once well known and in fact published about fifty years even before that date.

Alas, he did not live to see its re-publication, in English, as Elizabethan Casuistry,23 in 1981. It was a Latin manual of casuistry, c. 1581: and a very rare copy is now in Lambeth Palace Library. In it, a crucial thomistic principle (ST 1-2 100.6, the decalogue as order of moral priorities), never mentioned since, is referred to and applied to a case of conscience where two precepts conflict in their bearing on it, the lesser precept giving way to the greater. Now clearly this is a constantly recurring situation even on the mundane level and in everyday life, well known to anyone who ever kept an engagement diary, though the corresponding casuistic principle, about how to prioritize conflicting moral obligations, is nowhere mentioned in the post-Tridentine moral tradition firmly insisted on by Fr Davis. The Latin manual was drawn up by two former Oxford dons, a Cardinal, William Allen, sometime Fellow of Oriel College, and a Jesuit, Robert Persons, once Bursar of Balliol, for training future seminary priests for the English mission, while they were still in exile in France or elsewhere. The seminarians are advised right at the start, as a rationale and a guiding principle for the entire subject, about the comparative values and the sense of proportion, in terms which when put into English begin thus.

It should carefully be noted [Allen and Persons state] … that the difficulties to be found in [the cases that follow] are matters of divine, human, and canon law, and that on these laws the solution [‘resolution’ in Dr Holmes's translation] of such cases depends. What is against divine law [meaning, natural law, lex naturae] cannot be made lawful by any Papal dispensation or concession, although, by authority of the plenitude of power which resides in him, the Pope may declare something to be or not to be against divine [natural] law … But what is against divine [natural] law can be made lawful in only one way; that is, only by means of the divine law itself, when two divine precepts [meaning, of the decalogue – two of the ten commandments] have a bearing on a particular case and it is necessary to violate one of them. In such circumstances the more important precept prevails …

And they give a curious example, topical at the time, in illustration of the principle that precept V, the fifth commandment (forbidding homicide, putting other people's lives at risk, one's own also) takes precedence over precept VII (lower down the list, concerning ownership and theft), when they are in conflict. Hence if innocent lives will be put at risk by his trying to return it, Titius must keep the money, at any rate till the situation [in the Cecils' police state] changes.

Now that general principle – the decalogue as embodying moral priorities – is quite indispensable for solving cases of conflicting obligations. And St Thomas in fact identifies six or seven interlocking sets of priorities, in ST 1-2 100.6,, when elaborating the Sed contra from St Paul, Romans 13:1, ‘everything coming from God is subject to order’. (Well, we could hardly expect the ten commandments to have been revealed in the wrong order!) But this interesting and vital thesis will not be found in Génicot, Arregui, Fr Davis - or, as his silence surely implies, anybody else since 1634. The consequence has been that ad hoc methods of solution have had to be used instead, all these years, at the discretion of ‘experts’, themselves unaware of the general rule. And that presumably rendered necessary the invention and use of highly controversial systems such as ‘probabilism’. Despite the paradox, then, the corpus of moral doctrines now needs amplifying –‘up-dating’– by a straightforward return to the St Thomas who was seemingly last put to work as a moralist, by Allen & Persons, in 1581.

Another consequence of the disappearance, from the casuist's toolkit, of what we may call the ‘Allen-Persons doctrine’, for prioritizing obligations in conflict, is the manifestly defective understanding of the double-effect doctrine. The muddle itself is only too well illustrated by an article by the American Jesuit Fr Joseph Mangan, SJ, in 1949, entitled ‘An historical analysis of the principle of double effect,’24 where the writer begins by stating that different moralists have used the principle to arrive at contradictory conclusions about identical cases and then goes on to give an example of a case which can, he says, be solved by double-effect – though in fact the case is one of conflicting obligations, not of double-effect. It is taken from 1 Maccabees 6:40-47, where Eleazar slays the Persian king's elephant by stabbing it from underneath, expecting to die when it falls on him: and by so doing he turns defeat into victory, sacrificing his own life to save his hard-pressed people. That they were on the verge of defeat, being greatly outnumbered, could certainly be called a ‘proportionately grave reason’, the key condition in double-effect, traditionally regarded as justifying the deed despite its evil effect, which was his own death. But double-effect still does not apply here: and why not, we shall shortly see.

We should note, however, that the terms ‘double effect’ are in St Thomas, who used the adjective both attributively and predicatively; and also that the doctrine itself was later derived uncritically from his rational argument in justification of self-defence, given in ST 2-2 64.7 What has to be vindicated, there, is the agent's right to use proportionate violence against an unjust attacker ready to kill him, even if that means unintentionally killing his assailant. (The same moral question arises in Cicero's plaidoyer Pro Milone, but is dealt with far differently, of course.)

The argument offered in the corpus articuli involves, most rarely altogether, a lapse of reasoning, being made to depend on the premiss that ‘one is bound to take more care of one's own life than of somone else's’: plus tenetur homo vitae suae providere quam vitae alienae. On the face of it, that looks like two obligations being compared: conversely, two moral evils, two instances of dereliction of duty, one worse than the other. But if that were his meaning there would be nothing left to prove, and the argument a petitio principii– a charge we need hardly consider. Alternatively, if he is understood as comparing two physical evils, two disasters, the greater to be avoided by tolerating the lesser, the argument is simply not conclusive, since the only convincing way of comparing two physical evils as a greater and a lesser is to show that one contains the other as the whole contains the part.

Now that was precisely the case when Captain Oates, badly frost-bitten, famously limped out of the tent and into the antarctic blizzard, never to be seen again (on the return journey by Scott's expedition to and from the South Pole in 1912).25 He did that so as not to destroy his comrades' chances of survival, by obliging them (as English gentlemen, who could not just leave him behind) to walk at his pace. Not suicide, then, but a clear-headed choice between them all dying, if he stayed with them, or just himself if he gave them the slip, as his ingenuity inspired him to. That is double-effect, through and through: not indeed a baptised, RC variant on making the end justify the means, but a natural-law principle rooted in Aristotle's Nicomachian Ethics (3:1, 1110a4-11) – the fear of the greater evil, which is equally natural in all of us, as Friar Reginald also observed, ST Suppl.47.2, c.

On the other hand what is not double-effect, despite Fr Mangan, is Eleazar's case, just mentioned, since as far as we are told he knew (like most brave men patriotically sacrificing their lives in war) that he might well have survived otherwise, his own death not being an inevitable consequence of defeat. For just that reason the disaster that defeat represented did not include, logically and physically, as a greater physical evil, the lesser – which could only have been his own death. The moral justification for Eleazar's deed therefore depends on what we have just called the Allen-Persons principle (though really it's St Thomas's), since patriotism falls under the IVth precept and takes precedence, where necessary, over the Vth, enjoining self-preservation. And indeed, despite much writing to the contrary, the application of double-effect to war-fighting is very restricted altogether, for the same reason.

But the defect in St Thomas's argument about self-defence (just this once) is that the agent's own death does not itself contain, logically and physically, the lesser evil, which as he indicates is the assailant's death. It does so only in a ‘doctored’, poetical sense, where one's own death ends everything – the attacker included. But what sort of an argument is that? To be really convinced we surely need the literal, objective sense observed by Captain Oates, where a greater evil can truly include a lesser as the whole includes the part and the case is a straightforward question of damage-limitation, mandated by fear of the greater evil. If so, then, St Thomas's argument here about two physical evils seems to need touching up, to be rendered intelligible and convincing.

But now surely in the concrete the real danger, the truly overriding evil, would be that both victim and attacker got killed, fighing it out. If we make this provision the argument can be strengthened: and then all becomes clear. When unjustly attacked the innocent victim is not bound, normally, to let himself be killed: but he is not bound either to avoid killing his unjust attacker if that is a necessary condition for staying alive himself - which St Thomas presumably meant, though he did not say. For in that case he is doing no more than avoiding the greater evil of them both getting killed, which is exactly what ‘defending himself’ means, in a situation where the adversary is obviously intent on killing him. And in that case the right of self-defence surely has to be interpreted all the more liberally, the more obvious the adversary makes it.

And so it was, by cowboys in the Wild West – and ever after, in the cinema. When you needed to get your shot in first to stay alive, there could be no obligation just to stand there waiting to be killed. But no licence to kill, either – not deliberately so. As John Wain used to say, ‘I didn't have time not to’, so confirming Doctor Johnson's remark about what concentrates the mind wonderfully. Quietly reading St Thomas can also do that – and is less dangerous.

  1. 1 Thus e.g. John Mahoney, The Making of Moral theology (OUP, 1987), p.xviii (‘explicitly for beginners’) and p.78 (‘intended for beginners’); also, ‘The study of the Summa Theologica’, by the Rt.Rev. H.L.Janssens, OSB, Titular Bishop of Bethsaida, first contribution to St.Thomas Aquinas, Papers from the Summer School of Catholic Studies held at Cambridge, August 4–9, 1924, ed. Rev.C.Lattey, SJ, Cambridge (Heffer), 1925, pp. 8–9: ‘In a preface as short as it is modest, the author declares that he intends his work ‘for the instruction of beginners’. We should note also that what some call the Summa Theologica others, for some reason unknown to me (Foster, n.2, and Kenny, nn. 3 & 16, infra), call the Summa Theologiae. In my copy, Parma, 1852–7, 14 volumes (17.5 cm. × 10.5 cm.), the title page proclaims Summa theologica - though 11 times only, owing to a misprint in vols VI, VII, and VIII, where the ‘h’ is omitted.

  2. 2 See, e.g., The Life of Saint Thomas Aquinas/Biographical Documents, translated and edited with an Introduction by Fr. Kenelm Foster, O.P. (1959), passim.

  3. 3 For William of Moerbeke see Anthony Kenny, Aquinas (OUP Pastmaster, 1980), p.13, and indeed passim, for much relevant historical information, concisely expressed.

  4. 4 Cf. H. Ritter & L. Preller, Historia Philosophiae Graecae, 1831–1898 [8th edition], G.S.Kirk & J.E.Raven, The Presocratic Philosophers (CUP, 1957–69, quoting copiously from Aristotle); likewise, Henry Jackson's Texts [to illustrate a Course of Elementary Lectures on the History of Greek Philosophy from Thales to Aristotle] (Macmillan, 1901, 19142). I have been unable to find this short passage from Aristotle's Metaphysics in any of them.

  5. 5 Bertrand Russell, A History of Western Philosophy (1946, Readers' Union 1954), in the chapter on St Thomas Aquinas, where a footnote to p.477 in the RU edition, says, ‘But in Aristotle the argument [proving the existence of the unmoved mover] leads to 47 or 55 Gods’.

  6. 6 Cf. J. Maritain, St Thomas Aquinas [ET, J.F.Scanlan, 1933], p.157.

  7. 7 Ludwig Ott, Fundamentals of Catholic Dogma (ET, Cork, 1957), p.17, refers to the canon at Vatican I anathematizing atheism, Denz.1801, and mentions learned views on the point (despite St Thomas's thesis to the contrary, ST 2-2 1.4-5).

  8. 8 Cicero, De divinatione 2:58

  9. 9 For relatively inexperienced readers, such as young philosophy students for whom this is required reading, the original must be barely intelligible: surely part of the mystique (not to say, fraud). Whether or no, the original wording can be found in An Enquiry Concerning Human Understanding, part 1, section IV, p.28 of the Oxford edition, 1894, ed. L.A.Selby-Bigge, reprinted from the posthumous edition of 1777.

  10. 10 A.D. Woozley, in his Introduction to John Locke: An Essay Concerning Human Understanding, Fontana pbk 1964/73, p.23

  11. 11 Kant, Kritik der Reinen Vernunft [KRV], erste Aufgabe, S. 499, zweite S.492, … so verlohnt es sich wohl der Mühe, den Gang seiner Schlüsse und die Verirrungen eines so einsehenden und schätzbaren Mannes, die doch auf der Spur der Wahrheit angefangen haben, so weit es zu meiner Absicht schicklich ist, vorstellig zu machen.

  12. 12 At the top of p.493 (second edition, p.499 in the first): Erfahrung ist eine [solche] Synthesis der Wahrnehmungen, welche meinen Begriff, den ich vermittelst einer Wahrnehmung habe, durch andere, hinzukommende vermehrt.

  13. 13 …leere Zeit, empty time. KRV, S.293 (zweite Ausgabe), S.293 (erste). Denn man setze: sie habe einen Anfang. Da der Anfang ein Dasein ist, wovor eine Zeit hervorgeht, darin das Ding nicht ist, so muss eine Zeit vorhergegangen sein, darin die Welt nicht war, d.i. eine leere Zeit ist. ‘Suppose the world had a beginning; then the beginning is a reality before which a time elapsed during which it was not there, i.e. an empty time.’ In his commentary on the Pentateuch Philo Judaeus observes that those words ‘In the beginning’ refer, not to a beginning in time, but to the beginning of time: for there was no time before the world [existed]: chronos gar ouk én pro kosmou. Peri tés Môuseôs Kosmopoiïas, 1:7.)

  14. 14 A bibliography appears on pp. XLIX-L of August Messer's edition of Kant's KRV (Knauer 1923).

  15. 15 … duplex est demonstratio. Una quae est per causam, et dicitur propter quid, et haec est per priora simpliciter; alia est per effectum, et dicitur demonstratio quia, et haec est per ea quae sunt priora quoad nos. Cum enim effectus aliquis nobis est manifestior quam sua causa, per effectum procedimus ad cognitionem causae. Ex quolibet autem effectu potest demonstrari propriam causam ejus esse: si tamen ejus effectus sint magis noti quoad nos, quia effectus dependeant a causa, posito effectu, necesse est causam praeexistere. Unde Deum esse secundum quod non est per se notum quoad nos, demonstrabile [nihilominus] est per effectus nobis notos. (ST 1 2.2 c.)

  16. 16 Woozley also: see n.10 supra. Likewise A.J. Ayer, of whose Oxford ‘Pastmaster’ on Hume, advertized at the end of Kenny's on Aquinas, n.3 supra, we are told that he ‘argues that Hume's discovery (!) of the basis of causality and his demolition of natural theology were his greatest philosophical achievements’.

  17. 17 Among them, Anthony Kenny also: ‘Having come to have a great respect for St Thomas Aquinas as a philosopher I decided that the best place to start [seeing whether any of the proofs of God's existence were valid] would be an examination of the five ways by which he says, in his Summa Theologiae, that the existence of God can be proved’, A Path From Rome (Sidgwick, 1985), very near the end - last page but one. See also n.3 supra (1980), p.16: ‘… the two Aristotelian proofs of the existence of God in the earlier work are replaced by the clearer, brisker, and more famous Five Ways …’. By way of sharpening our focus on St Thomas's use of Aristotle we should perhaps add that 20 pages later, p.36, Kenny broaches the problem of ‘transubstantiation’ in the Eucharist and the possibility of accidents inhering in no substance, airing the strictly Aristotelean doctrine for two pages and pointing out on p.38 that, within that logic and sticking to the definition of ‘accident’ as something existing only by inhering in a substance, there is no such possibility. Of course. But not too surprisingly St Thomas also considered the question, ST 3 77.1 obj.2, and answered it in the only way possible – by actually quoting Aristotle himself, who observed that existence is not a genus: Analytica Posteriora 92b14, ou gar genos to on, a consideration which affects the way that substance and accident need logically to be defined. Now while there is presumably no warrant whatever even for supposing that Aristotle ever considered any such possibility as accidents inhering in no substance, the fact remains that we simply do not know what he thought, only what he wrote. So Aquinas argues, ibidem ad 2, that because existence is not a genus, a description of anything, cum ens non sit genus, what makes a substance a substance or an accident an accident cannot be their esse, existence itself, hoc ipsum quod est esse, non potest esse essentia substantiae vel accidentis (meaning, that the said existence would then occur on both sides of the specific difference –non in alio– when applied to ‘ens/being’ as if it were a genus, whereas in contrast when you apply, say, the difference ‘rational’ to the genus ‘animal’ you do get a complete disjunction – man/animal and no third alternative). He concludes that the Aristotelean definitions of substance and accident are not adequate here and need touching up, in the light of what Aristotle himself said. You could only say that there is no third possibility, to add to substance and accident-inhering - no ‘accident-not-inhering’ - if the specific difference defining ‘substance’ (in se) had indeed been applied to a genus – whereas it is applied to existence itself, ens, ‘being’. Hence the disjunction substance-accident is logically not complete, but only empirically so: and the strictly logical alternative to ‘existing as substance’ is not ‘existing as Aristotelean accident’ but, treading more cautiously, ‘existing not as Aristotelean substance’– a bare possibility left open by the Organon 92b14, accident without substance, the one required to validate the purely logical possibility, pace Kenny, of transubstantiation. The objection, then (St Thomas's own), that transubstantion is not possible even by a miracle, because Aristotle's definition of ‘accident’ has to be violated to make it happen, is answered by making the logical adjustment (implicitly allowed by Aristotle's words, if not his thoughts) and by conceding that the divine power is necessarily involved, sustaining the accidents, high and dry. But then, as Aristotle saw (and Aquinas agreed), it is only the divine power, that of the prime mover, which can sustain anything, ontologically: the very cause of all other existence, even that much.

  18. 18 Thus e.g. ‘It is for my readers to judge whether the proof advanced can be said to amount to a demonstration’: A Two Year Public Ministry/Defended/by Edmund Sutcliffe, S.J. (1938, London, Burns Oates and Washbourne Ltd, monograph No.1 in The Bellarmine Series), p.5.

  19. 19 Cicero, Tusc.Disp., Bk I, Lipsiae, Teubner, recog. C.F.W. Müller, 1895, p.308.

  20. 20 Edward Sillem, Ways of Thinking About God/Thomas Aquinas and some recent problems (Darton, Longman & Todd, 1961).

  21. 21 Thus e.g. Fr John Mahoney, op.cit. n.1 supra, p.61, n.76, where the liceity per se of ‘natural family planning’ is said to contribute ‘to the puzzlement of many’.

  22. 22 Henry Davis, S.J., Moral and Pastoral Theology/in four volumes, London, Sheed and Ward, fourth edition dated 1943, Preface, vol. one, p.vii-viii. Opposite the title page the first edition is dated May 1935 though the Preface just quoted is dated 8th September 1934. The concept of sin is defined on p.203: ‘… a morally bad human act, a privation of some obligatory good, a deflection from the order of right reason, and therefore from the law of God … a voluntary transgression of some moral law …’. Compare that with Matt. 7:12.

  23. 23 Elizabethan Casuistry, Catholic Records Society Monograph No.67 (1981), by P.J. Holmes: pp. 61–126, The Allen-Persons Cases. The Latin original in Lambeth Palace Library is said, on p.7, to be drawn almost entirely from a manuscript listed as MS 565, ff.16-55v and entitled ‘Resolutiones quorundam casuum nationis Anglicanae’ (solution of certain cases of the English nation), catalogued in 1812.

  24. 24 Theological Studies 10 (1949), 41–61.

  25. 25 See e.g. E.R.G.R. Evans, South With Scott (Collins, 1921), p. 239.