Now first let me welcome you to this lecture, and especially if this should happen to be your first experience with philosophy. I must say that I feel somehow inadequate to talk to you. On the one side, I feel that I should give a kind of sermon. And on the other side, I dislike preaching. So I am caught between two things. In addition to all this, and quite apart from the fact that I dislike sermons, I have the feeling that I am getting old and that I am not very good at it. First of all, I am not English and my English is deteriorating with age. But I am also getting more and more liable to ramble, which is also a consequence of age, as too many experiences and memories seem to crowd themselves into my mind. Bad sermons are particularly questionable things. But I am not a good lecturer either. So I must ask you not to expect too much. Lectures are sometimes enjoyable, sometimes boring, but always, in a certain sense, unimportant. The important thing is the work that you are doing yourself. This work you can do partly during the lecture. And there is a certain amount of work that can probably be done only in the lecture. For lectures give us the opportunity to ask questions, and for that they are valuable, since it is only through asking questions and attempting to answer them that one is able to get any deeper into a problem. But one can always become a great scholar without lectures. And in that sense they are dispensable: if you think and read, then you can become a great scholar without them.

I want to begin by telling you what I think is the real aim of a university education. I will try to be brief about this, though I must warn you from the beginning that many people think very differently from the way I do. I believe that someone is well educated only if he realizes in great detail how little he knows. And I think that this is really very important. I think that a man who has the feeling that he knows a lot is somehow badly educated. Yes, one can know a lot, namely, about all the problems and theories that have arisen owing to the growth of our knowledge. And one cannot really live in our world today without realizing how quickly our knowledge, and especially our technological knowledge, has grown. But there is a difference between pure knowledge and applied knowledge. And the main point, at least with regard to pure knowledge, is to recognize the many open problems that lurk in all the knowledge that we have achieved. Without that l would say that you are not really educated.

The aim of pure knowledge is to understand: to understand the world in which we live, to understand society, to understand ourselves, and to understand this great miracle of human
knowledge. Human knowledge is indeed quite miraculous, and it is especially miraculous if we are, as the biologists tell us (and I think that they are probably right), descended from lower animals. This is really one of the central problems that we will be dealing with here. And it is undoubtedly one of the most interesting phenomena that can be studied. Understanding the world in which we live is the main aim of all knowledge and of all our education. The more
we know about it the more we realize that this is a very huge task—that it is, in fact, an infinite task. And the more we know and the more our knowledge grows, the more modest we should
become about all those things that we don’t know.

Now, I have already used the word ‘understanding’ several times, And this activity of understanding is something that we will talk about a lot, especially in the first two weeks or so. I won’t talk about the word ‘understanding’, but about how we do it—about how we understand something. But I want, especially, to encourage you to interrupt me if you feel that I am saying things that are too difficult to understand. I want you, if possible, never to leave this room with the feeling that you have not understood what I have said. Or, if that is not possible, I want you to come back to the next lecture and ask me, and challenge me, about it. I really mean challenge me, not just ask me, because it is very bad if I say things that you don’t understand. It is one of the things I shouldn’t do—though one always does, because there is always a give and take in understanding. But it is especially important, just because of this necessary give and take, that you always feel free to interrupt me and to criticise what I say. There is, in my opinion, an important connection between understanding and criticism. It is, in fact, one of my main points that we can always improve our nderstanding of something by criticising it—that criticism is, in
fact, the chief way in which we can improve our understanding.

There are, in my opinion, lots and lots of degrees of understanding. The lowest degree is if you leave this room and say, ‘I have understood every word he said’. A slightly higher degree is if you are able to reproduce, or to report and explain, what I have said. A still higher degree is if you can improve on my presentation in what you tell other people about what I have said. And a still higher degree is if you cannot only explain what l have said, but also why it is all wrong. There are also, in my opinion, very many levels of criticism. It is, however, very important to distinguish between two of them. One level of criticism is when you say to yourself, ‘This seems wrong, but I’m not sure that I fully understand it’. Another level of criticism is when you have
understood something very well, but feel that it is wrong nonetheless. The first is a tentative criticism and the second is a serious one.

Now nobody is safe from being criticized, and criticism, in that sense, is always tentative, because the critic may himself be criticized. But there is still an important distinction between the sorts of tentative and serious criticism that I have just described. It is, for example, very important for criticism to be fruitful. And it is always possible to think that you understand something and that your criticism is serious when it is really tentative and due to misunderstandings. Distinguishing between these two levels of criticism—knowing whether or not you have understood something—is in fact one of the most difficult things to do. And it is made even more difficult still by the fact that your understanding can always be improved. So while criticism is most important, you should not expect too much from it. If you bring forward tentative criticism believing that it is serious criticism, or not understanding the difference, then you will be out to defend your criticism rather than to find out whether or not it is adequate. And in that case, it is very possible that the ensuing discussion will go nowhere at all.

So this distinction is most important, and you should always be very careful about whether you have really done your best not only to understand a point critically, but also to criticize your own
criticism before you put it forward as serious criticism. Tentative criticism can increase your understanding, and it can, for that reason, be an important step in learning. But it will do so only if you understand that your criticism is tentative, that it is of an exploratory kind, and not necessarily the kind of criticism that refutes what you have heard. For that, a deeper understanding may be necessary.

Here I should also say a word about the right and wrong attitudes of coming to a university. This is a sad story, and, in a way, I feel that things are liable to get worse. When I first began to teach, I used to joke to my first year students that some students go to a university in order to learn how to speak un-understandably and impressively. I used to mean this as a joke. But the joke has, with time, become serious. Today, many students really do come to the university with the hope that they will learn how to speak impressively. And this is a frightful mistake, even though the mistake is sometimes fostered by their teachers. This is the model that many of their teachers give to them. And I gather that there is at least one university in this kingdom in which people are judged, in the main, by the impression they create in what they say. But this, I think, is all wrong. There is one thing for which we all should constantly strive. Simplicity. Simplicity is the main thing.

I want to emphasise this point about simplicity, because it is one that I think is particularly important. There are very many writers, and especially philosophers, who sin against it. I think that it is a sin against the Holy Ghost. But I receive many papers that commit it, and I have an example of one right here. I won’t tell you the name of the author of this particular paper, but the paper was read at a recent congress for the philosophy of science. It is, in my opinion, one of those strange academic things that consist of very high-sounding terminology and practically nothing else. I’ll give you an example of the terminology. It starts with:

Abstract. The theory of hetero-automata, and its chapter, the theory of automata, are applications of semi-groups generated over the heterogeneous field of theoryconstructing

Now all of these things exist. Semi-groups exist. And there is a theory of theory construction, though it isn’t a very highly developed theory. But the whole paper is like that! All the words
involved are scientific terms, and all the sentences are grammatically correct. So it is not exactly nonsense. But it is just too difficult to tell what the whole thing means.

Some people write papers like this because they feel that they have to do so in order to show that they are experts. But if you want my advice for those who want to write papers rather than to find the truth, then I would simply say, ‘Don’t!’ That is all I can say about it.

You can fill infinitely many pages with infinitely many words. There’s no problem in that at all. But I am not interested in giving you advice on these lines.

Many years ago I wrote a book called The Open Society and Its Enemies, in which I said that we should be modest with our educational aims. We shouldn’t try to educate experts, but we
should try to educate people who can distinguish between a charlatan and an expert. But I think that we have singularly failed even in this. The charlatans are getting about more and more these days. And this kind of thing and really, this is only one example—this kind of thing gets into print, and suddenly there are whole associations of very well-meaning people writing papers like this on the theory of hetero-automata. These associations can even get hold of good people, and sometimes they have a tremendous amount of money, and it then becomes a kind of sham science that somehow lives more or less side by side with the non-sham science. You will understand that this is pretty discouraging and very sad.

Anyway, we should try to educate people to distinguish between a charlatan and an expert. But at the same time I wish to be tolerant even to charlatans—at least up to a point. Many years ago I used this formulation about distinguishing between the charlatan and the expert at a congress where I spoke, and I was then put in my place by a very great expert. He said, quite rightly, that people who seem to be charlatans may turn out to really have something to say.

I agreed with this man—it was the intuitionist mathematician L E J Brouwer—and I think that we should be tolerant and help people. Sometimes there are people who are, let us say, half or threequarter charlatans. These people sometimes produce an idea. And ideas are such rare things that one should be really careful and try to see whether there isn’t a little bit of gold in all that chaff, which is a difficult procedure. Perhaps it isn’t really charlatanism, but just a difficulty in formulating their ideas that leads to this sort of thing. So even this very modest aim may be difficult to achieve.

Still, I think that in many cases this sort of writing is due to something very different.

I am sure that you all know about the pecking order in hen yards in which the hens peck each other and erect a kind of hierarchy. Each hen knows whom she may peck and who is allowed to peck her. In my view, the theory of knowledge should start with an understanding of the pecking order among scientists. On top, of course, are the mathematicians. Then come the physicists. They are followed by the chemists and the biologists. And then, pretty low down, come the various social scientists. Now as a consequence of this hierarchy, there arises a sense of inferiority—especially among the social scientists—and attempts to rise in the pecking order.
And these attempts consist in the main of trying to acquire certain of the trappings and externalities of the hens higher up in the yard. Today, many of the less ‘precise’ sciences are aping the others and trying to make use of mathematics and statistics and mathematical
formulae, so as to become more acceptable in the hen yard. And this situation has led to an over-emphasis on precision and even to a preference for precision over clarity.

Most people regard clarity and precision as more or less the same. But in my opinion, there is a big difference between the two. In fact, I would say that clarity and precision are really to some extent opposed to each other. I think that if you try to be too precise, then you may well have to sacrifice clarity. And I also think that clarity is an end in itself, and that it should, for that reason, never be sacrificed for precision.

The fact of the matter is that there is really no such thing as absolute precision, neither in physics nor in mathematics, nor in the social sciences. Precision is always something relative. So you can never be simply precise in what you say, not even if you say it with mathematical formulae. But you can be as precise as the needs of your problem require—or, rather, as your problem seems to require, because you may always be mistaken. You can be sufficiently precise for the problem at hand. And that is all. But you can aim at being as precise as the problem demands, and that is something.

Precision is really a derived value. It is merely a means to an end. Clarity, simplicity, and even over-simplification!these are values in themselves. But precision is a derived value, and whether or not a certain degree of precision is necessary will usually depend upon the problem you are trying to solve. You probably know, for example, that Einstein proposed, as a test of his general theory of relativity, that we take photographs of the stars in the surroundings of the sun during a solar eclipse—this is when the moon is before the sun and hides the sun—and then compare these photographs with photographs of the same region taken six months later, when
the earth is on the other side of the sun. This would show whether the distances between the stars had remained as they were before, or whether, as Einstein predicted, they had shrunk. Now this shrinkage would be extremely small, so small that it would really be on the verge of measurability. But it would also be very important, since it would be a test of the general theory of relativity.

Here it is quite clear that the problem itself demands a very high degree of precision. But not all problems require this degree of precision, and there is, again, no such thing as absolute precision. So this is an example of how the degree of precision is prescribed by the problem.

Clarity is something completely different. Clarity and simplicity are ends in themselves. They are part of what is involved in trying to understand, part of why we submit our theories to self-criticism, and to criticism by others. All of this is done in an attempt to clarify something, to simplify it so that we and others can understand it. But the important point is that the ideals of clarity and precision often clash. If people feel that they have to be very precise in what they say, they begin to hedge their statements. Their statements then become much longer and by no means very clear. Clarity, on the other hand, requires the courage to over simplify things. And over-simplifying things always means that one is not being very precise.

Now many people regard over-simplification as a fault. But I would say that what we call ‘science’ is, in general, an oversimplification. There is no such thing as a science that does
not over-simplify. The mere picking out of a problem—this one out of the many that exist—is an over-simplification. So the question is not whether you over-simplify, but whether you oversimplify well or poorly. And this depends again on the problems that you are discussing.

The clash between clarity and precision means that as you become more and more precise, fewer and fewer people will be able to understand what you are saying. Now some people actually like this. I know a mathematician and logician who is really one of the outstanding people in his generation. But he is literally ashamed if he says something that can be easily understood, or if he publishes something that is not too difficult. He once published a lecture—I
had been chairman at the lecture and also on the editorial board of the journal that published it—and I tried hard to make him simplify it. But this was only a challenge for him to make it more
complicated. I think that he is really a first class man, and I don’t think he does this with bad intent. But this has more or less become the generally accepted fashion, and he really is satisfied only if he publishes a paper that only three people in the world can understand.

So it is not just an over-emphasis on precision. Lack of clarity is  now actually considered to be a virtue in academic work. This is especially true in the United States. One of my younger American friends has told me that his dissertation was actually criticized for being too clear: one of his teachers was worried that he would have no place to hide if he was criticized. And a former student of mine who later became a professor at M.I.T. told me the following story. An article of his had been accepted by a famous American journal—not a philosophical journal, though that is just an accident. But when he received the proofs he no longer recognized
his article, because it was now full of long words—‘polysyllables’—that he had never put into it, and he was quite surprised. So he wrote a letter to the editor and the editor wrote back saying: ‘I liked your article so much that I had to change it. I felt sure that it would not get the attention it deserves in the form in which you submitted it.’

Even people who don‘t like this sometimes feel compelled to do it. A famous American political scientist told one of my friends, ‘We have to speak like that, otherwise people won’t listen to us.’ And when I was visiting America, the head of a philosophy department there told me over the lunch table, ‘You know, I don’t dare to speak as clearly and simply as you do. I just can’t afford it.’

This is a very serious matter. And I think it is just terrible. I think that the consequence is that people will listen even less and less. All I can say is don’t worry about whether or not people will listen to you. That is to be left to them. All you can do is to say something that you think is worth saying, and hope that someone will listen to it. That is all. But I do believe that clarity and simplicity are values in themselves, that they are two of the highest intellectual values that we can achieve, and that they are a duty for educated people. We have had the great opportunity of devoting years of our life to learning. And I think we actually owe it to our neighbours who are not as lucky as we are to do everything possible to help them understand what we say.

All of this has something to do with my own method of lecturing, which I try to make as simple and clear as possible by covering the same ground over and over again. I will, in fact, try to give away all of my secrets in the very next lecture, so that my later lectures will really cover the same ground that I will try to cover there. This has a reason. The reason is that I want you to understand what I say, and since I want you to understand what I say, I want you also to listen critically to what I am saying. But in order to do that, you have to know where we are going. And in order for you to know where we are going, I have to tell you where we are going. So I have to start more or less at the end, or with everything. I sometimes describe this method as a sort of spiral that goes not from the inside out but from the outside in. First I will give you some vague idea, then I will come more and more closely to it. As I said, the reason for this is that I want you to see all the time what we are doing and where we are going.

DIAGRAM. A line of footsteps or a path leading inwards in a spiral.

My second main point today is about reading. I said before that you can become a great scholar or a great scientist without going to lectures. But I don’t think that you can become a great scholar without reading. And here I would say that it is, in the main, the quality that matters and not the quantity. It is more important that you read what you read carefully than it is for you to read a great amount. I must say a few words about this, because it has now become extremely important due to the publication explosion.

The publication explosion is, in my opinion, even more hopeless than the population explosion. It is, perhaps, not quite so serious as the population explosion. But it is, in a sense, just as difficult and destructive.

Some people think one can and should try to meet the publication explosion by learning to read more quickly. And to my absolute dismay—I usually don’t quarrel with my colleagues so I didn’t say anything to them, but I can say it here—to my absolute dismay the school has introduced a quick reading course. I was so upset by this that I went to one of the directors and said that I would introduce a slow reading course. This wasn’t at all well received, but I am absolutely serious about it. Anything worth reading is not only worth reading twice, but worth reading again and again. If a book is worth while, then you will always be able to make new discoveries in it and find things in it that you didn’t notice before, even though you have read it many times. That, at least, is what I have experienced, and it is something that many others have experienced as well.

But somebody recently showed me a very nice article in which a professor of psychology reported about experiments with quick reading courses. He found his experiments very encouraging and he wrote at length about them. He reported an average increase in reading speed of more than 50%. The only drawback he found was that understanding decreased. So you can read faster, but you don’t know what you have read. Now I myself do quite a lot of quick
reading, and I have also developed a technique for it. But I don’t rely on my technique, and that is the decisive thing. I don’t think that this technique is any great thing, or that it ever replaces
reading. But I want to tell you a bit about it, because it contains a feature that I think should really be made a general rule.

My method is to look at very many things and to throw most of hem away at once. And then, when I come across something that I feel is important, and that I might need, I study it very carefully. But there are, of course, many things that I find interesting, but not so important. And these I may have to skim through very quickly. Now skimming is not really wonderful, but it is often necessary. And now here comes the important point that I think should be made a general rule: You ought to know what you have skimmed, and you ought to know that you haven’t read it.

The terrible thing about quick reading is that people who read something quickly sometimes think that they have read it, and here they are deceiving themselves. They do really think, ‘I have read this book and I know now what is in it’. But it isn’t true. And this is a decisively important thing. Skipping and skimming is a necessary thing. You have to do a lot of it just to decide whether or not something is worth reading. But it has to be done with the full knowledge that you have skipped the thing.

Perhaps you will think that it is not quite as bad as all that. But there are lots and lots of examples of things written by reputable scholars that are explicable only on the assumption that they read too quickly and believed that they knew what they had only skipped and skimmed. I can cite a case from my own experience.

A world-famous philosopher once wrote a very long review of a book of mine, a review of some 30 pages, in which he attributed to me all sorts of views that I have never held. I had, of course,
discussed these views. But he had taken everything that I had italicised in my book as my opinion. Now the fact of the matter is that I had italicised all of my opponents’ opinions—I now think that this is a bad habit, and I try not to do it—but I had italicised those passages and had presented them as clearly and simply as I could so that you could see more easily what it was that I was attacking. But this man had obviously read only the italicised passages in the book, and perhaps the first sentences of each paragraph. And on this he based a very long review in which quite a number of the views that I had criticized and tried to refute were set out quite clearly as my views to be criticized by him.

Now this sort of thing is obviously the result of believing that one has read a book when one has only developed a technique for skipping and skimming.

And this is not an accident that happens only now and then. The whole learned literature is not only growing too fast, but it is now literally overflowing with comments by people on books that they obviously haven’t read—although they obviously believe that they have read them. I have no doubt that the people who have written these things may have done so in good faith: that they may honestly believe that they have read the works they are writing about. But they have only skimmed them, and they haven't really read them at all. I would say that in this publication explosion—it’s difficult to estimate—a very cautious estimate would be that 75% of the learned literature is like that. Someone reads something and believes he has understood it. But he has not really understood it. Perhaps it was too difficult—that is understandable, a man may
misunderstand something because it’s too difficult for him—but perhaps he has not really read it at all. Perhaps he has really skimmed it and only believes that he has read it. That is roughly
the situation.

So the situation is really desperate and I think that there is, apart from the various methods that you can take, one thing that is really essential: you should know that if you have read through
something only once, then you haven’t read it at all—you have only oriented yourself to what it is about, and before you write about it you have to read the passages that you are writing about
pretty carefully at least a second or third time. The main thing is to know what you have read and what you have not—what you have skipped and skimmed—and to distinguish between them.

This is something that we not only do not teach here in the university, we instead do everything we can to encourage the opposite. And university professors are no doubt partly to blame for it. We have, in many ways, taught our students how to not read, and how to believe they have read what they really haven’t. Perhaps it’s because we make you read too much. We demand so
much reading that you learn how to skip and skim instead. And what? With our requiring so much reading and your doing so much skipping and skimming, it’s a very simple thing to persuade yourself that skipping and skimming is the same as reading.

I say all of this as a university teacher and I say it especially because of my subject, which is, as you know, scientific method, and because the first thing in scientific method is the method of
reading a book. This is because science is more or less made out of books—I’ll say more about this next time—and this is part of the reason why it multiplies so fast. It is not made only out of books. It is made also out of thoughts about how to solve the problems that scientists and other people have had. But it is, in any case, made largely out of books—it is difficult to be precise, but I would say that about 95% of it is made out of books because scientists and many other people have found it useful to communicate their thoughts in books. It is made, in the main, by thinking critically about these books. And you obviously can’t think critically about a
book unless you have really read it.

We don’t ever start from nothing in science. If we did start from nothing, if we started from where Adam started, then there would be no reason to believe that we would get any further than Adam did. Adam, on the contrary, was probably particularly clever—and he also lived longer than most people—so there is every reason to believe that Adam got further than any of us would ever get if we really started from where he did. But even Adam, as far as we know, didn’t get so far as to learn how to read a book.

So books are terribly important for scientific method. And this distinction between careful reading on the one side and skipping and skimming on the other has become so incredibly important, because of the publication explosion. We can’t help skipping and skimming. And there’s really no crime in it. But it is of the utmost importance for you to clearly distinguish these activities in your own mind, and to never, ever persuade yourself—not even unconsciously—that you have really read something that you have only skipped and skimmed. The crime is only in mixing these two things up in your own mind, and in becoming accustomed to misjudging yourself, and to lying to yourself. That is really the dangerous thing.

Now I have only another second or two left. But you can already see that I tend to be somewhat critical of what very many of my colleagues believe. And some of you may, by this time, be saying to yourselves, ‘But he’s just another university professor. So why should I now believe what he says?’ And this, I think, is a very good question to ask. I could, of course, tell you that I am not just another university professor, that I am a professor of scientific method!and that I am, in fact, the only professor of scientific method in the entire British Empire. This would be the usual way to deal with the issue. But my real answer is that you shouldn’t believe me at all. On the contrary, I tell you all these things in order to warn you that you should not believe me, but that you should, on the contrary, try to understand me, and that you must, in order to do that, criticise me and force me to clarify and simplify my views—that you should try to argue with me, and to haggle with me as best you can. I will, of course, try to defend my views if you do but only partly.

IntroductionLecture 2