The Summa theologiae, Aquinas’s uncompleted master-work, is, according to its title, a summary of the study of God. This study of God — theologia — Aquinas himself usually called "sacra doctrina", sacred teaching, or "sacra scientia", sacred science. What these titles mean, and why such a study is necessary and opportune, is spelt out by Aquinas in the twelve articles of the first question of the Summa. The study of sacred teaching is necessary, he concludes, it is authentically a "science", in the Aristotelian sense, it is a single science, and it is a speculative science, though it has practical implications. It is superior to any other science, it is a kind of wisdom, and it has God as its object. Like other sciences, it proceeds by way of argumentation, and it depends on a correct interpretation of God’s self-revelation in Scripture.
The first substantive question, which follows the methodological articles outlined above, is whether God exists: a question which is prefaced by a discussion of whether the existence of God is self-evident, and whether it can be proved at all. Once these preliminary questions are settled, though, the first genuinely substantive discussion is, as I say, whether God exists.
Is this a philosophical question at all? If so, why does it come here, at the beginning of a summary of theology, of the science of God, studied in and through God’s own self-revelation? We need to answer these questions if we are to be confident that there is any interest of what we would call a philosophical kind in studying Aquinas on this point. To answer them we have to understand what Aquinas meant by a science.
Aristotle defined "episteme", the kind of knowledge that Latin Aristotelians called "scientia," as "definite knowledge through explanations". There is no doubt that St Thomas thought of this definition as correct, and that he used it out of respect for Aristotle’s authority.
Both expressions just used are important here. Aquinas thought of the definition as correct, and he used it out of respect for Aristotle’s authority. Before we begin to examine what the definition implies for the study of Aquinas’s Summa, and for the philosophical nature of the examination of the existence of God, we need to see how authority and truth were related in St Thomas’s mind.
For there can be little doubt that this feature of St Thomas’s work is one which is extremely alien to the minds of present-day philosophers. Even though, as we shall see, St Thomas undoubtedly thought of the existence of God as what we would call a philosophical question — briefly, a question that can be answered correctly by the natural light of human reason alone, without recourse to the content of God’s self-revelation — he does not think it at all odd to appeal to the authority of the Bible — putatively God’s word — in answering it. "Is there a God?" asks Aquinas and answers "Apparently not". He gives the two strongest arguments he can find for believing that there is no God, and then proceeds to explain why this appearance — that there is no God — is deceptive. The process is, as he calls it, argumentative. The arguments he gives against the position he is eventually to take up are the strongest he can find: this is his usual practice. In this case the arguments given continue to be the two most cogent arguments available. But he nevertheless appeals to authority: after giving the arguments against, the objections, as they are known, he at once begins his own response by quoting Scripture. There is a God, he says, because God’s own name, as revealed by God, is "I am who am".
Aquinas was aware that someone who does not believe in God will scarcely be impressed by an alleged revelation. In his earlier summary, the Summa Contra Gentes, designed for the use of missionaries among Muslims, he draws attention to the hopelessness of trying to use against Muslims Scriptures that Muslims will not accept. Muslims, to be sure, believed in God then as they do now: and while it is, I believe, a matter of some dispute among Muslim doctors about whether Christians really believe in the one true God or not, Christian doctors, like St Thomas, normally have no difficulty in concluding that Muslims believe in the Christian God, though they combine it with what a Christian regards as an over-simple view of God’s internal life. (Christians, according to Muslims, hold what must be either nonsensical or blasphemous beliefs about a Trinity within God. To what extent these beliefs could bring it about that the Christians are deceiving themselves when they claim to believe in the one God of Abraham and the Prophets is, I think, a disputed question among Muslim theologians.)
Was it that St Thomas, though acquainted with Muslims, did not know of the existence of atheists? Surely not. He knew enough history of ancient philosophy to refer to the Epicureans, and they held that there were no gods, or that if there were, they were only a part of the system of randomly generated worlds of which we also form a part. He knew, surely, of the various philosophers and sophists labelled by their contemporaries as "godless" (atheoi). He knew of the existence of the Emperor Frederick II Hohenstaufen — after all, he put to death at least one of Aquinas’s family — who was alleged to be an atheist. One who lived so much among the young would not have been more ignorant than was Adelard of Bath, whose young nephew, about a century before Aquinas’s birth, told him that many of his contemporaries held that there was no God, or that God was identical with nature. Above all, if I may myself use an argument from authority, Aquinas believed in what he read in the Bible: and in the Book of Psalms it twice says "The fool has said in his heart, there is no God" — a text, incidentally, quoted by St Thomas within the same question as the Five Ways.
Thus we can be sure that Aquinas knew that his use of an argument from authority would fail to convince in arguing against an atheist, and that there were such people as atheists. Why, then, does he use this argument?
The simplest answer is, perhaps, that he always uses such arguments: they are an indispensable part of his argumentative procedure, his way of handling a question. Medieval learning in the universities at this period proceeded by way of the quaestio, the "question" in a technical sense: the discussion for and against a given thesis. This might appear as a real debate, which might or might not be recorded and published, with more or less editorial input; or it might just mean the use of the quaestio-form in a published work. The latter is what we have in the Summa. In either case the question was announced, and arguments for and against either side were put: in a live debate, suggested by the students. In a live debate the master’s assistant, the bachelor, would marshal these into some kind of order — sometimes, for example, playing off one against another — and present them to the master. In a composed work in quaestio form the master would do this, more briefly, for himself. The master would then give his "determination" — his magisterial solution — and then deal with whatever objections to his answer had not already been resolved.
The form of the live debate was followed in a streamlined way in works composed in this form. In such a work, like the Summa, the more streamlined questions are at some remove from this process, though not wholly detached from it. But in either case, in a live debate or in a question-based textbook, there was always an appeal to authority, an authoritative text given at the outset of the "determination", to support the line the master had decided to take.
Clearly this way of proceeding is very foreign to our way of doing philosophy. While even today a typical article in a philosophy journal will contain a high proportion of footnotes that give references, the texts are seldom, it is claimed, being used in an authoritative way. They are typically, or notionally, being used to show that a given author did indeed hold the view that is being ascribed to him, or because the author cited has expressed a point better than the author citing can hope to do. Or at least, this is what we hold. And there seems little doubt that the medievals did not use authorities in this way. Clearly the fact that Aristotle said that p is being taken, by the medievals, to be a good reason for believing that p. We do not believe this, or profess that we do not. All contemporary philosophers would at least say that they refuse to accept such an "argument from authority". Indeed, one sometimes comes across cases of contemporary authors in philosophy who are inclined to reject a thesis simply because it was said by some older philosopher who has been highly regarded by others. This last attitude is perhaps abnormal and should be dealt with by psychological rather than philosophical or historical investigation: but the existence of such an attitude highlights the contrast between the modern and the medieval. Given that we at least believe that we do not appeal to authorities in the way that medieval thinkers did, how should we react to their texts?
There are two obvious ways of reacting, which I should wish to reject. The first is that of people like Bertrand Russell, who held that the use of the argument from authority shows that the medievals were not doing philosophy at all — or, more modestly, that the medievals were not doing what we call philosophy. This kind of reaction is unfortunate, since one who reacts in this way is unlikely to bother to read the medieval philosophers, and thus unlikely to be able to learn anything from them.
Another reaction is more intelligent, and less disastrous, but it still in the long run shows a failure of understanding. This is the reaction of those who are not put off by the use of the argument from authority, and read on in the medieval philosophers. Those who do so soon discover that beside these, to us, unacceptable arguments from authority, there are other arguments which are, by our standards, very good indeed. This may lead them to read further, to become interested in medieval philosophy for the modern-style arguments that they can find in it; and they will thus become accustomed to skip the frequent arguments from authority, or to regard them as being of merely historical interest, as indicating the sources of the writer. In short, they will read the medieval writer as if he were a modern.
This is a mistake. It is to fail to grasp what is distinctive in the medieval author. Read in this way, the medieval author will not be able to tell us anything very different from what a modern author would tell us: so we might as well read a modern author. We will not have our eyes opened by the shock of discovering a radically different way of thinking. Above all, we will not really have understood the authors we are studying.
The modern who reacts in this way can find some justification even within medieval writings. It is often said that the most important parts of a conceptual framework are those that are never discussed, but taken for granted; but we are fortunate in that there were discussions among the medieval philosophers about the use of arguments from authority, despite the fact that arguments from authority formed an important part of their conceptual framework. The reason for these discussions is not that medieval thinkers had any doubts about the value of authority in general: it is rather that arguments from authority had different values when the authority they were based on was a human authority, and when the authority they were based on was divine. Hence we find these discussions, one of which, perhaps the best known and most accessible, is to be found early on in Aquinas’s Summa theologiae, in the methodological first question.
Aquinas says that the argument from a divine authority is the strongest argument of all, while the argument from a human authority is the weakest of all. This conclusion would be supported by most other medieval thinkers. The reason for this distinction is that human minds, even when honestly applied, are quite often mistaken, and sometimes may be applied dishonestly: while God cannot be mistaken, cannot be deceived, and cannot deceive. Hence "Aristotle says such-and-such" is obviously of much less weight than "God says such-and-such".
There are complications, of course. There is the question of the interpretation of the authority: what exactly did Aristotle mean when he said that such-and-such was the case? Every statement needs to be interpreted in the correct way: and this means, in practice, that it is rarely necessary to contradict an authority. Perhaps the text of Aristotle seems to say clearly that there are no centaurs: but even if you had seen a centaur, you need not say that Aristotle was wrong. You might argue that Aristotle meant something slightly different from the obvious sense of his words.
No-one would be likely to worry about such a trivial case, of course: but the possibility always existed. This made it possible to blur in practice the important theoretical distinction which has been referred to, between the different strengths of divine and human authority. You could never straightforwardly contradict a thesis with divine authority behind it: that, the medievals considered, would have been unreasonable. (And given their premisses, they were surely right.) The argument from divine authority was stronger than any other. But what was the correct interpretation of the statements made with divine authority?
The answer to that question would commonly rest on human authority: the usual or obvious interpretation of Scripture had been made by some human being at some time. It might typically derive from St Augustine. But the argument from Augustine’s authority, that this interpretation is in fact the correct interpretation of Scripture, is an argument from human authority.
Thus, for example, the Bible tells us that King Solomon made a large round vessel for the Temple, a vessel which measured ten cubits across and thirty cubits round. The natural interpretation of this passage implies that ?, the ratio between the diameter of a circle and its circumference, is three. Probably no figure respected as an authority by the medievals ever upheld this natural interpretation: certainly Augustine would not have done so. But if any had upheld this interpretation, the human authority of that writer, which was an argument in favour of this interpretation, no matter how great his authority might be, would have been vulnerable to stronger arguments drawn from the science of geometry. The medievals knew that ? is not three, and so would have claimed that the natural, literal interpretation of God’s authoritative statement must in this case be rejected, despite any argument from human authority in favour of that interpretation. The interpretation of this passage in the Bible must be such that we take it to be giving only rough measurements. The argument from God’s authority is the strongest of all: it is invulnerable to any other argument. But the argument from the human authority, which might be brought in favour of the literal interpretation, is the weakest of all arguments: it is vulnerable to any other argument, let alone one as strong as a proof of geometry.
It is thus possible for the modern reader to justify his ignoring arguments from authority when he finds them in medieval writers on the grounds that the medievals did not take them very seriously either. The argument from human authority is, even to the medieval reader, the weakest of all: are modern philosophical readers of the medievals not justified in regarding this argument as being so weak as to be negligible? Moreover, modern philosophers probably do not believe in God, or even if they do, they may have very different ideas about what God may be supposed to have said, and how he said it, from the ideas the medievals had: are modern philosophers not then entitled to believe that what the medievals thought of as the voice of God was in fact a merely human voice, the voice of Isaiah or St Paul? Are they not accordingly entitled to treat it as a human authority, the weakest argument, which modern philosophers regard as negligible?
This is a fair point: but there is a feature of Aquinas’s discussion that should cast doubt over this typically modern reaction. When discussing the thesis that the argument from human authority is the weakest of all arguments, Aquinas cites the human authority of Boethius in its support. This should make us think. The argument from human authority, for Aquinas, though weak, is not negligible, as he is willing to cite it even in support of the weakness of arguments from human authority.
We can sum up the difference between the medieval and modern attitudes to authority as follows. For the moderns the voice of authority is no argument at all: for the medievals it was an argument. Admittedly it was the weakest argument of all, so that any other argument was stronger: but it was none the less an argument. You needed another argument to refute it, before you could ignore it. The moderns think they can just ignore it without any other argument.
For the medievals, if Aristotle said that centaurs did not exist, and you had no stronger reason for believing that centaurs did exist — for example, the evidence of your own senses — then you had good reason for believing that centaurs did not exist. There was an authoritative statement: so the question "Do centaurs exist?" was not purely an open one. Since an authority had spoken on the subject, the burden of proof and the form of the question were established. It is therefore a mistake for modern readers to understand the medieval position, that the argument from authority is the weakest of all, as a polite under-statement of their own position, that the argument from authority is no argument at all. This is not what the medievals meant: they meant what they said, that the argument from authority was an argument, even though any other form of argument was stronger.
The medieval attitude to authority, then,was different from ours. Do we just have to accept this as a brute fact, or can we come to have some imaginative grasp of what it meant to have this different attitude? Can we even come to understand it, to see that it is at least not totally unreasonable or superstitious, as some modern philosophers might tend to regard it?
The best way to go about this task of understanding, I think, is to try to see how our own attitude to authority is itself not self-evidently correct, but stands in need of an explanation: an explanation which is rather hard to find. I think that this self-examination — this instilling into the reader of the philosophy of the past a feeling of strangeness about his or her own unexamined beliefs — is of the greatest value in coming to understand the past, and also is one of the elements of greatest educational value in the study of past beliefs.
It would perhaps be permissible to say that the main attempt of modern philosophy has been to give a firm foundation to knowledge. At the back of our minds all of us moderns have the idea that all our knowledge derives either from experience or from self-evidently true principles. This notion derives from Descartes and his heirs, from the typically modern (i.e. post-Cartesian) project of founding all knowledge on true, certain and indubitable principles. Now, that which we believe because we have been told it — that which we believe on authority — though it may be true, is far from being certain or indubitable, at least by post-Cartesian standards. But we should try to clear our minds of this cant, and consider the matter calmly. If we do, we should be able to realise that most of what we believe we believe because we have been told it: we believe it on authority. Now we should be clear that on our own principles we have no right to believe this. As a result, it is our own attitude to authority that looks odd and in need of explanation, not that of the medievals.
It is in fact entirely reasonable to believe what we are told. Most of what we are told is true, and when false, it is usually in itself unimportant, or false in unimportant ways. Moreover, when it is false, we can often correct it — usually, let me add, by being willing to learn from better authorities. To restrict our actions to what we can do on the basis of our own experience and on deduction from self-evident principles would be to restrict our action unreasonably. Also, it is clearly unreasonable to believe what we are told while also believing that we have no right to believe what we are told, which is, in fact, roughly what the modern position is. If we do believe what we are told, as we do — if we do trust in authority, as we do — then we should recognize the fact. Thus: it is reasonable to trust in authority. It is unreasonable to trust in authority and pretend that we don’t. We can even go further: it is simply unreasonable not to trust in authority.
How do we decide what is reasonable and unreasonable? In particular, how does a modern philosopher come to the conclusion that it is unreasonable to trust in authority? The answer must be, by applying his standards of reasonableness. The crucial question which follows on from this is, how do modern philosophers acquire their standards of reasonableness?
I am sorry to say — or rather, I am really rather pleased and amused to say — that standards of reasonableness are acquired on authority. When we were children, we were brought up under authority. This teaching to a great extent made us what we are: it introduced us into our community: into our family, into our nation, into the human race (considered as a social phenomenon) as full and active members. There are two things to be noticed here. The first is that we needed to be introduced: we could not have attained this status on our own. We were made into full members of the club. We had, no doubt, a right to be made members of the club, in virtue of our birth into this species: but without our upbringing, and the use of authority in this upbringing, this right would never have been exercised.
The other thing to notice is that this community is not just the community of those now living. My great-grandparents were dead before I was born: but part of what I am I owe to them, physically, psychologically and culturally. Despite all the generation gaps that exist or have existed, what we learn on the authority of our parents about who we are, about what to believe or do, is substantially the same as what they learnt from theirs. The differences which we know to exist between the attitudes of different generations are only noticeable because they stand out against a background of agreement. This is what it is for a culture to exist. It is passed on by authority, and it continues through time by tradition: what is passed on by the authority of a parent generation is mostly passed on by the authority of the child generation to its children.
But nowadays we never speak of this. Tradition, like authority, is seen as very much a second-best: something to be superseded: something, perhaps, that is necessary in childhood, or in past centuries, but not at all to be welcomed by adults of today. Instead, we say, we should trust in reason.
To see through the fallacy involved in this popular slogan we should notice the fact that if we are to trust in reason we need to know what the standards of reasonableness are. We do in fact have standards of reasonableness, as the little child does not. That is why we have to use tradition and authority in teaching children: there can be no dispute about this. But what is seldom noticed nowadays is that we have standards of reasonableness because we have been initiated into our culture by means of tradition and authority. Once we have the standards of reasonableness, we can challenge this or that part of traditional authoritative teaching in the name of these standards of reasonableness: that is, we can challenge doubtful parts of the tradition in the name of more basic parts — perhaps, in the name of the tradition as a whole. But we cannot use part of the tradition to challenge the tradition as a whole: we cannot claim that it is unreasonable to hold to any tradition, when the very standards of reasonableness which we are employing in this challenge only come to us from tradition. The unreasonableness of such a claim is like the unreasonableness of the following sentence: "It is impossible for there to be an intelligible sentence written in the English language."
It should be noticed that what I am myself doing here is precisely issuing a challenge to one part of our culture in the name of the standards of reasonableness that form another part of it. I am challenging our modern attitude to tradition, because it is not reasonable, and I make the challenge in the name of the standards of reasonableness that I hold as the fruit of tradition. This seems itself a reasonable challenge. What I could not do is challenge our modern culture as a whole for being unreasonable as a whole, because my standards of reasonableness derive from the tradition of this culture, with a little help from reflection on ancient and medieval culture. The modern opposition between tradition and reason is as unreasonable as a universal attack on the unreasonableness of modern culture as a whole would be.
It would, indeed, be possible to maintain that it is not only unreasonable not to trust in authority: it is also impossible. There is a rabbinical story of a Gentile who came to Rabbi Hillel, asking to be taught the Law. But, he went on, he only wanted to be taught the written Law, not the oral Law: that is, he wanted to be able to read God’s written word for himself, without the glosses put on it by the wisdom of the teachers of Israel. The story is of Rabbi Hillel, who was renowned for his kindness and courtesy, so the interview did not end at that point, as it might well have done if the Gentile had gone to another rabbi. Rabbi Hillel began by writing out the Hebrew alphabet on a sheet of paper and telling the Gentile to come back once he had mastered it. The Gentile, nonplussed, replied that he recognised the Hebrew alphabet, and admitted that he would have to master it before he could be taught the written Law, but he didn’t know which letter was which. "Ah," replied the Rabbi, "so you want me to tell you which letter is which?" In the same way we need to be taught our very language, on authority, if we are to be able to systematise even our own experience sufficiently to make it into anything that could be a foundation of other knowledge, or to grasp even self-evident truths.
Even if trust in authority is necessary, it still is hard for us, in our culture, to appreciate the fact. To help us, we can perhaps draw attention to a number of features of even our society and culture in which authority and tradition are paramount, even though they are not generally recognized. Religion is still mostly a traditional affair, even though many theologians do not seem to realise it , or even deny it. A couple of cases currently in point are the ordination of women, and allowing priests to marry. The best argument against women’s becoming priests is that this has never been done: that restricting the priesthood to men is something which the Christian Church has done in a traditional faithfulness to the inscrutable will of God, as first revealed in Christ’s choice of the apostles. Theoretical arguments based on a supposed appropriateness of males for the priesthood certainly exist, but they seem weak. If the argument from authority and from tradition is not accepted, there seem few compelling reasons for continuing to do as has been done up to now; but if authority and tradition are recognised, the reason they give is entirely compelling. The same point is true of the marrying of priests. Journalists, commentators and even theologians nowadays fail to distinguish between the question of whether we should allow or even encourage married men to become priests, from the question of whether we should allow those who have become priests to get married afterwards. This failure to distinguish is based on a failure to recognise the importance of tradition. Different Christian communities, of undeniable apostolic tradition, have over the centuries had different opinions, for different reasons, of whether or not one should allow married men to become priests. No Christian community of unquestioned apostolic tradition has ever allowed priests to marry after becoming priests. The tradition is clear and strong, but we seem nowadays incapable of recognising it or regarding it as important. Once it is recognised, other arguments have to be evaluated in terms of whether they are strong enough to overthrow the argument from authority and tradition. The question is not an open one, which we are called upon to answer out of our own heads, as if for the first time
Religious tradition, however poorly understood by religious believers or commentators these days, provides a clear reflection of the attitudes of earlier ages. But there is another parallel: we can compare the pre-modern attitude to the tradition of learning to modern traditions of science.
For Plato and Aristotle, to become a learned person, a philosopher, is a process that involves admitting the authority of the philosophical tradition, involves accepting the attitudes, beliefs, behaviour and standards of that community. These attitudes include attitudes to the history of that community, and hence attitudes to the tradition itself. Like the traditional reasonableness of the human race, and like religious traditions, such a tradition has its own standards, which are also accepted on the authority of tradition. These can be used to judge individual parts of the tradition, or individual features of the present state of the tradition in this generation, which may be found to be defective in one way or another. But of course the tradition as a whole cannot be judged as not up to standard by the standards of that tradition. It could only be so judged by outside standards: and it is not at all surprising that those with different standards should judge it badly. But they are likely to misunderstand it: as much as we misunderstand the medievals. There are no neutral standards.
We can, if we wish, compare with the tradition of learning as understood by Plato and Aristotle the tradition of the scientific community in our own day. This is perhaps the nearest we come in our society to a community based on a genuine tradition. The truth about this is disguised from us by the rhetoric used by journalists, philosophers of science, and even by scientists themselves about "reason": but in fact the scientific community is a traditional one, based on authority. Those who wish to enter it have to give up whatever other beliefs, standards and attitudes they may have had, and adopt, on authority, the new standards of the scientific tradition. They cannot hope to justify the beliefs, attitudes and standards of science by means of beliefs, attitudes and standards which they bring from outside. Among these attitudes, it is important to notice, is an attitude towards the scientific tradition itself: an attitude to the history, or rather the story of science. The story of the scientific tradition which the newcomer must accept is not a detailed history of everything that any scientist has ever done in the name of science: it is a genuine tradition, a story which picks out only those things which are to be believed at the present day, or have in some way contributed to what is believed at the present day. This is very much the same as the way in which newcomers into a religious tradition are not told about all the heresies there have been: they are told the Faith. Once newcomers have established themselves in the scientific community, they may use the standards of science to correct this or that current or recently past view: but they cannot use the standards of science to overthrow science.
It is indeed, no coincidence that while we do not find appeals being made to authority in articles in philosophy journals, we do find them in scientific journals. The average paper in Nature, as Geach has pointed out, contains far more references to past work than does the average article in the Summa Theologiae
It will be said that the two cases are not on all fours: that the results cited in an article in Nature are, at least in principle, repeatable, while the authorities cited in the Summa are not. This would involve a confusion. Clearly, the authorities cited in the Summa do not refer to repeatable experiments, since theology is not an experimental science. But they do refer to repeatable reasonings. The experiments are unrepeatable because there are no experiments: but the reasoning is repeatable, which means that it is open to question, and open to revision. Notice that there is no contradiction between the attitude of such post-modern contemporaries of ours as Quine, and the attitude of St Thomas, while both attitudes are strongly at odds with the modernist, foundationalist conception of science and philosophy. Quine thinks we should regard any proposition which we hold as being in principle reviseable. But this reviseability in principle requires that we should hold the rest of our belief system steady while we revise the belief in question, and make whatever subsequent adjustments to the system that thus become necessary. The rest of the belief system can be used as lever and fulcrum to overthrow any given belief because we are able to treat the rest of the belief system as fixed. There is no bedrock truth: but at any time some beliefs must be treated as if they were fixed. Often they will be methodological beliefs: and for this reason St Thomas begins the Summa by setting out his methodology. In the same way some at least of our standards of reasonableness must be received from authority and held fixed if we are to overthrow others. In the same way, within science, our trust in older scientific authors and in the validity of their experimental methodology must be held fixed if we are to believe that their results are even in principle repeatable.
To sum up, then, if St Thomas frequently cites Aristotle, or St Augustine, it is because, as we said at the beginning of this discussion, he both has respect for their authority and thinks that what they say is correct. St Thomas’s trust in his authorities is not a blind trust, like that which the Pythagoreans are said to have had in the ipse dixit of their master: it is a rational trust. It is not just that St Thomas has this trust: he is able to expect his readers to have it too. His readers are to be students and masters in the schools, people who have a share in the tradition which he is developing. This seems alien to modern philosophy, and indeed it is: but it is not alien to the practice of modern science, and it should not be alien to the philosophy of those who, like Quine, are struggling to throw off the dogmas of modernism, in either its rationalistic or empiricist forms.
I have often found, when leafing through university prospectuses, that philosophy is recommended to the prospective student by some phrase such as "Philosophy teaches you to challenge accepted wisdom, and question everything". My only comment is: who says so? Is this phrase not a part of accepted wisdom? Should it not then be questioned? In fact, the student who questions everything (and you always get a couple every year) is no more likely to be successful in philosophy than he is in science, engineering or the law. Philosophy teaches you to question the things that philosophers usually regard as questionable, no more and no less. There is no doubt that the exclusion of the student who wishes to raise the sceptical doubt in every single philosophy class is a necessary condition of progress in this as in every other form of learning. That in St Thomas’s day the exclusions practised were different from ours should raise no difficulty. That these exclusions were more extensive than ours is a difference of degree and not of kind. Some may feel that any loss that was incurred through the breadth of medieval exclusions was more than made up for by the speed and intensity of the development that these exclusions made possible.