What distinguishes Science from Pseudoscience? (The demarcation problem)

What distinguishes science from pseudoscience? (The demarcation problem)

According to Imre Lakatos in “For and Against Method“, The demarcation problem may be formulated in the following terms: what distinguishes science from pseudoscience? This is an extreme way of putting it, since the more general problem, called the Generalized Demarcation Problem, is really the problem of the appraisal of scientific theories, and attempts to answer the question: when is one theory better than another? We are, naturally, assuming a continuous scale whereby the value zero corresponds to a pseudoscientific theory and positive val­ues to theories considered scientific in a higher or lesser degree.

This is not an esoteric problem just for armchair philosophers, and I will give you a few historical examples-which you all know-where such demarcation criteria could have helped.

First, let us take the 1616 banning by the Catholic Church of the works of Copernicus, and particularly of his De Revolutionibus Orbium Caelestium. A few of you may know the grounds on which the Inquisi­tion tribunal based its judgement: the book was considered pseudo­ scientific and rejected because it contained too much speculation. The text of the ban reads that the book will be banned until it is proven. In the 1820s the Church removed the book from the Index, maintaining that the theories contained in the book had been proven. As you know, Einstein came much later!

 Let me mention another example which concerns an authority similar to the Inquisition: in 1949 the Central Committee of the Soviet Com­munist Party discussed the merits of Mendelian genetics as opposed to Lysenko’s environmentalist theory. They decided that Lysenko’s theory was better, and the leading authority of the rival school, N. I. Vavilov, was killed in a concentration camp.1

Let me point out that Galileo, Copernicus’s main supporter, while leading an extremely comfortable life in comparison to many of his contemporaries, continues to this day to enjoy the reputation of a suffering hero, when he actually was not, whereas Vavilov, who most certainly was, does not. Another difference between our two examples is that although the Church banned the book, it did not ban its discussion, whereas in the Soviet Union even the discussion of Mendelian ideas was banned.

Our third example: last year [1972] the American Philosophical Association discussed the following proposal put forward by Hilary Putnam, professor of philosophy at Harvard University. It said:

The American Philosophical Association should endorse the Ameri­ can Anthropological Association’s condemnation of the racist, sexist and anti-working-class theories of Richard Hernstein, William Shockley and Arthur Jensen as dangerous and unscientific.2 This is not a question of non-scientists interfering with a scientific controversy, and it is our duty to point out that an ideology with no specific scientific merit is trying to disguise itself as science. We condemn the irresponsible support given to such unfounded theories by the Atlantic Monthly and The New York Times whose publication invites serious reflection of the issues con­cerned, especially in view of the destructive political uses to which such theories could be put …

and so on. The motion was passed.

The main point is that the conclusions of these theories were ‘unfounded’. This is exactly the same reason given by the Church in Copernicus’s case: his theories were not sufficiently proven from facts. Let us move on to a less dramatic case which you probably all know about: I am referring to Velikovsky, who in the 1940s proposed a certain astronomical theory. The publisher who published it had reason to regret his decision soon enough, when he found that the leading scien­tists who usually published with him refused to submit further texts, refusing to work with someone who published science together with pseudoscience.3

These examples are enough to show that the demarcation problem is far from being an esoteric problem, and that its solution could affect our lives, especially at a time when research grants are state-controlled, science is subject to a monopolistic patronage, the mass of publications is such that it is impossible for us to judge everything ourselves, and intellectual parasitism is on the rise, making us feel we would enjoy having a few people thrown out of their jobs-I mean chairs.

The demarcation problem as I have illustrated it is, of course, very similar to the problem I inherited from Popper, who founded his philosophical reputation on his so-called “falsifiability solution.” I would like to read out a few passages from Karl Popper so that you can see what bothered him and his generation. Let us go back to the Vienna of the 1920s. The chairs in philosophy in Austrian and German universities were held primarily by Hegelian philosophers at first and later by Heideggerian. Vienna was quite a lively town: it was host to the Vienna Circle of Logical Positivism, and Sigmund Freud lived there, as well as Alfred Adler, the socialists of the Second and Third International, and Kurt Gödel, the leading mathematical logician of the time. It was not the provincial outpost on the European border it is today, but one of Europe’s intellectual capitals. It is here, too, that we come across Karl Popper and Ludwig Wittgenstein, both school teachers in Vienna in the 1920s. In fact, for some years Popper could not even get a job as a school teacher and became a cabinet maker, which is no doubt why he got interested in the demarcation problem as a kind of special machine in which one feeds, for example, a few inaugural lectures by these fashion­ able philosophers and the machine flashes up “meaningful” or “mean­ ingless,” and if the response is the latter, then both the chair and its holder go up in flames. This was, as a matter of fact, Leibniz’s original idea. In the seventeenth century Leibniz wanted to construct a machine which would flash up the word “false” if you fed in a mistake.

I will read out two passages from Hegel, just to give you an idea of what Popper and his colleagues in the Vienna Circle were up against: Hegel was as much at the centre of study as, let’s say, Newton’s theory of colours. Hegel’s philosophy of nature was considered proper science. In his Open Society (vol. II, page 290), Popper quotes Hegel’s definition of heat: “Heat is the self-restoration of matter in its formlessness. Its liquidity [is] the triumph of its abstract homogeneity over specific defi­niteness; its abstract, purely self-existing continuity as negation of ne­gation is here set as activity.” Let us follow Popper to page 332 of his Conjectures and Refutations where he quotes Hegel’s definition of elec­tricity: “Electricity [ … ] is the purpose of the form from which it eman­cipates itself, it is the form that is just about to overcome its own indif­ference; for electricity is the immediate emergence, or the actuality just emerging, from the proximity of the form [ … ].”I will not go on. From the point of view of proper science today, this is nonsense, and we would most probably not appoint a man like Hegel to a chair!

But when we come across cases like Velikovsky’s, it turns out that Velikovsky is a pseudoscientist simply because quite a few astronomers tell us so. If we go on to ask according to what criteria we think that Velikovsky’s theory is, in actual fact, pseudoscientific, we realise that ac­ cording to Popper’s criteria this theory is falsifiable. So, what is wrong with this? This is not an easy question. But as I shall show later on, the problem in reference to natural science is easier than with the so­cial sciences; as luck would have it, most chairs here at the London School of Economics are in the social sciences! To illustrate the deplor­able state of the social sciences in Germany in the 1930s, I shall quote Popper once again. He is in his turn quoting Heidegger, Selbstbehaup­ tung der deutschen Universitiit-Das Rektorat (1933-1934): “To will the essence of German universities is to will the essence of science itself; it is to will the historical, spiritual mission of the German nation, as a nation which has reached its full consciousness in the experience of its State. Science and the German destiny must together attain power in the essential will.”

This is the background against which one has to place the Vienna Circle’s attempt to divide meaningful from meaningless. If I compare these remarks with today’s sociology textbooks, for example, I have a difficult time spotting the difference. So, as you can see, the demarcation problem is far from being unimportant because it is a question of determining what criteria should be satisfied in order to have a moral justification to burn down the LSE-and I assure you that I am sorry the revolutionary ’60s are over!

Before moving on to the social sciences, I would like to describe the three main schools of thought on the demarcation problem.

Let us call the first school militant positivism; you will understand why later on. The problem of this school was to find certain demarca­tion criteria similar to those I have outlined, but these also had to satisfy certain boundary conditions, as a mathematician would say. I am refer­ ring to a definite set of people to which most scientists as well as Popper and Carnap would belong. These people think that there are goodies and baddies among scientific theories, and once you have defined a demarcation criterion, you should divide all your theories between the two groups. You would end up, for example, with a goodies list in­cluding Copernicus’s (Theory1), Galileo’s (T2), Kepler’s (T3), Newton’s (T4) … and Einstein’s (T5), along with-but this is just my supposition Darwin’s (T6). Let me just anticipate that nobody to date has yet found a demarcation criterion according to which Darwin can be described as scientific, but this is exactly what we are looking for. And I suppose that if I do not want to be on bad terms with the mathematical economists at LSE, I should perhaps include in this list Walras and Marshall. But Marx certainly does not belong here.

Let us now group the baddies: Velikovsky would be a pseudoscien­tist, and Marx too. Popper would probably put Marx with the goodies, as you may know from his Open Society, but Soviet Marxism, as practiced in the Soviet Union, would go with the baddies. Then of course we would have Freud, Adler, Marcuse and Levi-Strauss. But this is not ex­actly correct. Why? Simply because demarcation criteria judge theories and not people, nor their collected works. We know, for example, that Newton wrote certain theological works that contained funny ideas about fallen angels; Kepler, too, had some ideas about musical harmo­nies in the heavens-so we are really talking about very specific and well-articulated theories, and not about people in general, as human beings or as they are represented by their collected works.

Briefly, according to militant positivism we have a programme to find a definition which puts every theory in its proper place. However, be­fore dealing with this research programme, I would like to mention two other schools of thought.

One of them is known under different names: scepticism, epistemo­ logical anarchism and cultural relativism are all synonyms for the line of thought which goes back to the ancient sceptic, Pyrrho, and has its main supporter today in Paul Feyerabend, whose work “Against Method” ap­peared in volume 4 of the Minnesota Studies.4 If we follow the sceptics, the demarcation problem is unsolvable. The reason is very simple: there is no demarcation line; epistemologically speaking, all theories are on a par. Scepticism regards scientific theories as just one family of beliefs which ranks equal to thousands of other families of different beliefs. Any one of these families-or systems-is not more right than any other, even though some have more might than others. While there may be changes in systems of belief, there cannot be any progress. Accord­ing to the Positivists, there is a line of progress leading up at least to Einstein; the epistemological anarchists, on the other hand, do not admit any such progress: what they see are only changing fashions, ‘bandwagon effects’. This school of thought, temporarily silenced by the stunning success of Newtonian science, is today regaining momentum. According to this view, philosophy of science is a perfectly legitimate activity: one can have a demarcation criterion (what a relief!), but it may or may not influence people. Note that epistemological anarchism has nothing to do with Mao’s “let a hundred flowers bloom,” since ‘flowers’ is, of course, a normative term. Rather, flowers and weeds may bloom together-there is no demarcation line between them. This presents a very important problem. Feyerabend has absolutely no intention of im­posing a subjective distinction between flowers and weeds on anybody. Any system of beliefs-including Popper’s philosophy of science-is free to grow and influence any other, but none can claim epistemologi­cal superiority.

And what about intellectual honesty? This too is a very interesting problem. According to militant positivism, it is simply dishonest to publish anything pseudoscientific. Of course, one can disagree about what science is, depending on whether you follow the Church or Professor Putnam. The Church says that you cannot publish any unproven theory if it is in conflict with the Bible, but are free to do so once it has been proved. Professor Putnam, on the other hand, maintains you cannot publish any unproven scientific theory, unless it is in the interest of the American proletariat, as seen through his own visionary eyes.

According to Popper, intellectual dishonesty means putting forward a theory without specifying the experimental conditions under which it could be given up. I remember when back in my Popperian days I used to put this question to Marxists and Freudians: “Tell me, what specific historical or social events would have to occur in order for you to give up your Marxism?” I remember that this was usually accompanied by either stunned silence or confusion. But I was very pleased with the effect.

Much later I put the same question to a prominent scientist, who could not give any answer because, he said, “of course anomalies always spring up, but somehow sooner or later we always solve them.” This is why, according to Feyerabend, who follows in Popper’s footsteps, all these criteria for intellectual honesty have one and the same function: they are empty rhetoric to frighten school children. Feyerabend’s only piece of advice is to remain faithful to yourself- to do your own thing and not let yourself be judged. He adds that along with his logic courses he also gives a course in Black Magic and other similar alternatives. Feyerabend’s stand is not exactly a laughing matter. We may, for in­ stance, choose to consider the mortality rate among Christian Scientists who do not accept artificial medical help and only wish to be healed by God. The interesting thing in this case is that their mortality rate is not perceptibly higher than among academics. I came across an interesting case in The Observer yesterday-perhaps you saw it, too-about how a couple of dozen psychiatrists went under assumed names to other psy­chiatrists and were subsequently put into mental hospitals.

So the sceptics can always point to the fallibility of scientific theories, and occasionally they are right. It does not necessarily follow that the more scientific the beliefs, the happier people are: consider the Swedes, for example, who have the most perfect socialist society in western Eu­ rope, and appear to be very satisfied with themselves on moral grounds if you take into account the intensity of their anti-Vietnam activities, and yet have a higher suicide rate than, say, the Azande people.

The Freudian theories and Marxism also appear to have something which Einstein’s theory of quantum electrodynamics lacks. If you happen to meet someone who works in these latter fields, you usually find you are facing a person subject to frequent headaches brought on by the number of problems he has to solve, someone who has many doubts about the whole theory, who doesn’t really know if he is coming or go­ing, who sees puzzles everywhere. Now consider a committed Freudian or Marxist: he lives in a state of happiness, he can explain everything, and enjoys that happy, relaxed state of mind called ‘understanding’. If you go to a theoretical physicist, he usually says: “I do not understand what is going on in the universe, but I have some theories and occasion­ ally my experiments work; but I still do not understand what God meant with this chaos.” Approach a Freudian or a Marxist, on the other hand, and everything falls into place. This reminds me how impressed I was by Popper’s phrase: “all-explanatory theories have an irresistible effect on the weak mind.” The phrase is, of course, sarcastic; however, some beliefs make people happier than others. [ … ]

According to epistemological anarchism, intellectual influence is di­rectly proportional to the vocal energy, the faith and the propaganda skills of competing groups. I think I had better come back to this school later on. But I would like you to think that I have dealt fairly with this solution to the demarcation problem: it has certain attrac­tions. Sceptics-not all of them, of course-usually say: “Truth? There is no such word.” If one mentions the word “truth,” they say: “well, what is truth? Truth is what the victor believes.” If a struggle between beliefs occurs, and one emerges victorious, that belief is what we call “truth.” I have thought a lot about that: for instance, we know now that Copernicus- Galileo actually- really earned a sort of propaganda vic­tory over Ptolemy. However, most people think that Galileo’s theory is true, but that judgement is not held in the light of Einstein. Another example: most people believe the years 1917 or 1789 to be moments of progress in history. However, if we take another point of view, one can regard-as I do-1917 as the year the new Dark Ages began. In my view, 1945 is the year the only great colonial empire of the twentieth century, namely, the Soviet one in Eastern Europe, was established; but it is also the year of the glorious victory over the Nazis. As you can see, there are many beliefs, and many points of view: who can tell which is better? Of course, if this theory is true, we shall never come up with a definition of demarcation. Let us leave the New Left for now and come to the Right.

Let us now come to another school of thought: elitist authoritarian­ ism. It believes that there is a demarcation between the goodies and the baddies. For the benefit of the sociologists who are in the audience, I shall immediately add that this view is currently represented in the phi­losophy of science by Polanyi, Kuhn and Merton.5 This is actually the standard view institutionalised today in scientific organizations such as the Royal Society. According to this view, there is a demarcation, but there are no demarcation criteria. Why? Because the difference be­ tween science and pseudoscience is inarticulable. Only a wise judge- a great scientist, for instance- can see the difference. So you can have a jury but you cannot have a law. A law, of course, gives the jury guid­ance, but the jury has to interpret it. And yet, according to this theory, there can be no laws, there is only the jury of wise men.

The great scientist sits in judgement and decides what is good science and what is bad science. Fellows of the Royal Society appoint further fellows, and professors appoint further professors. In conclusion: yes to demarcation, no to demarcation criteria.

London University has a beautiful way of preserving confidentiality in filling chairs, which is very much in this tradition. Let us suppose the University is about to appoint a very important professor: say six can­didates are short-listed. The referees report to the committee and an official from Senate House reads out the reference report to them. Now, supposing there are three reference reports for each candidate, the committee is faced with eighteen reports. The man reads them all out and when the original reports are passed around the table each referee can look at them very quickly, but no copies are allowed. A decision is reached in less than one hour. As you can see, the appointed professor emerges like a conservative leader, and there are no criteria with which to judge his theories, and the whole thing is clouded in esoteric mystery.

Those of you who are with the Department of Government here at LSE will know all about Oakeshott’s6 theory of politics, which is very similar to the case we have examined. According to this group of people, demarcation criteria are hybris. How can a mere philosopher devise criteria for distinguishing between good and bad science, know­ing it is an unutterable mystic secret of the Royal Society? In Professor Oakeshott’s view, politicians can make politics, but political philosophy is impossible-this is what his philosophy aims to point out.

History is, of course, very interesting for these people, whatever their criterion. Historians of science belonging to this tradition are bound to show that Galileo was better than Copernicus, that Kepler was better than Galileo, that Einstein was better than Newton, and so on. It lies with the historian to examine all this in detail. According to scepticism, certain influences in history may bring sudden changes in intellectual fashions. However, authoritarianism maintains that the Royal Society may finance a history of science, but not a philosophy of science. Similar to a royal court, it keeps its court historians. It could, for example, give you £2,000, or whatever amount, to set sail from England and follow in Darwin’s path and find out he vomited somewhere in the Indian Ocean. This is more or less all a non-scientist can really say about great scientists; in this tradition, as we have seen, we are landed with court historians.

The same people who argue in favour of this tacit dimension (Tacit Dimension is the title of one of Polanyi’s books) also argue in the fol­lowing way: suppose you wanted to learn to ski, would you go to the library and read a textbook, or look up the rules of skiing in a book? Of course not. You go straight to the best skiing instructor and try to imi­tate him. We are talking about two different things here: the question in this case is how one learns to do science. The answer is: sit at the feet of the great scientists-sit at the Mandarin’s or the great Rabbi’s feet and you too will become a great Mandarin or a great Rabbi, or a great sci­entist; or a great politician, if you first become private secretary to a great minister.

The interesting thing, however, is not only to learn to ski, but to learn to judge who is the better skier. In order to do this, you have to sit at the feet of the great scientist for decades. There is a lot of evidence for this view; if you check the statistics, it turns out that Nobel Prize winners are usually disciples of other Nobel Prize winners. This is a curious characteristic of the genealogy of science. For instance- and we are now talking about the field of science but of course further on we will want to generalize this demarcation criterion to all fields of intellectual exercise-we might find that a brilliant young man goes to Oxford and comes out five years later a complete idiot; whereas if a mediocre student goes to a good department, he will not only embark on a good career, but he may also reach some quite creditable achievements. So you can see there is quite a lot to say for Polanyi, and the principle of academic autonomy-non-interference from gov­ernment or students-actually stems from his philosophy. Outsiders cannot judge scientific achievement and should not have a say in matters scientific.

Polanyi put forward his ideas in the 1930s primarily to counter Soviet­ like intervention in academic life. I think that this was a very worthy exercise, and one has to have some sympathy for this theory. Do not forget that this academic autonomy is also saying, in a negative way, that the Catholic Church, the Central Committee for the Communist Party, the Nazi Party and so on, should leave scientists alone. This is the “truth content” of this school of thought. Let me briefly add that the sociology of science as it exists today actually latches on in some way to this school of thought. Merton, who is a leading sociologist of science of our time, raised the problem in the thirties: it is terribly difficult for a young man to choose his master, since at the age of eighteen, according to Polanyiite philosophy, he cannot tell the master from the fraud, and yet he must decide at whose feet he will sit. It is a sort of existential philoso­phy: a leap into darkness. Merton tried, also against Soviet and Nazi meddling with science, to find the norms of a scientific community. We should at least try to recognise the differences between a scientific com­ munity and, say, the Communist Party. So he had his famous criterion: namely, Communism, in the sense that there is no private property of knowledge in science, and only priority disputes exist, but they play a weak role in Merton’s sociology of science. [ … ]

To sum up, if elitist authoritarianism is right, instead of a demarca­tion between science and pseudoscience, we would have a demarcation between a scientific community and a non-scientific community.

The interesting thing is of course that this school of thought cannot explain two matters: (1) how it is that rival schools can come off the same production line, the same scientific community, and yet remain rival, with one perhaps calling the other pseudoscientific. Is it that the same school produces both good and bad science, or rival scientific theories? The other problem is: (2) how scientific revolutions come about. Is a sudden change in the scientific community progress or degeneration?

Thomas Kuhn solved these two problems with two postulates. Re­ member that Russell calls postulates “intellectual theft.” Kuhn postu­lated that in each scientific community there is always a dominant “paradigm” (which is of course sheer factual nonsense) and brings up another problem: how is it that people believed in the paradigm in the first place? Secondly, he postulated that if scientific revolutions occur in a community which satisfies Mertonian socio-psychological standards, they are always progressive. That means that within a scientific com­ munity might is right. So, if a revolution occurs, this implies increased knowledge. This is really Kuhn’s contribution to the debate, and you can see that he is really a rather ad hoc footnote to Polanyi and Merton.

In this case, therefore, if we want to judge the results, we have to look at the people who produced them and not at the scientific theories themselves. So, we have this socio-psychological demarcation between scientific and non-scientific communities, but we still have not come up with the answers to the two questions.

One question is: What if a scientific community degenerates, namely, it changes its views always for the worse? Because logically, of course, there is nothing impossible in a scientific community’s first holding Einstein’s views, and then undergoing a Kuhnian conversion to New­ ton’s- this is actually what happened with elementary particle physics. The second point is: What shall we do in the social sciences? In the social sciences, in order for fellows of the Royal Society to elect other fellows, we actually need a Royal Society. But there is no Royal Society in the social sciences. How do we go about electing the first fellows? The question, therefore, is: how do we start the social sciences? Do we first judge their programmes or do we first establish a community of social scientists along Mertonian or other standards? What is the first task? First institutionalize doctrines which are not there, or start by pro­ducing doctrines and forget about the institutionalization? If we decide to forget the institutionalization, how can we judge the product, since our only criterion is to judge the institutionalized community? This is why the social sciences are considered such a plague and also, as we shall see, why they play such a central role in this whole problem.

I think I shall stop here; next time-I shall outline the course in a single sentence-I shall show you how the different demarcation criteria were proposed, how they failed and were replaced by better ones; I shall then arrive at my own scientific research programmes, and then come back to Feyerabend and Polanyi.


  1. The works of Trofim Denisovi<; Lysenko (1898-1964) provided the guidelines of Soviet scientific research right up to Stalin’s death in Nikolaj Ivanovi<; Vavilov (1887- 1943), a botanical scholar opposed to Lysenko’s theories and authoritarian attitude, was deported to Siberia following Lysenko’s accusations.
  2. See Jensen 1969 and Shockley 1971a,b. also below, lecture 6.
  3. In Worlds in Collision Immanuel Velikovsky set forth the theory of “cosmic catastrophism,” according to which the planets in the solar system were not fixed in their Earth, especially, was subject to impressive cataclysms caused by gigantic comets. One of these was thought to have passed very close to Earth during the captivity of the people of Israel in Egypt, thereby causing the division of the Red Sea. Velikovsky’s theory would seem to imply that peoples who lived at the time of any similar cataclysm would have recorded it, which is certainly not the case, since many peoples who lived at the time of the events referred to in the Bible do not seem to have even noticed them. Velikovsky attempted an explanation of this fact by referring to a sort of “collective amnesia.” Cata­ clysms, he argued, would have had such traumatic consequences that the peoples involved would have tried to forget them, and consequently would have avoided any mention of them in their historical accounts. Velikovsky’s book, first published in 1950, climbed to the top of the best-seller list within a few days after its appearance, provoking furious reactions among scientists. Notwithstanding its huge success, the book was withdrawn from the market-for the first and only time in the history of American publishing-and reappeared soon after, thanks to another publisher. This whole story is the subject of The Velikovsky Affair, edited by Alfred de Grazia (1966).
  4. Lakatos is referring to “Against Method: Outline of an Anarchist Theory of Knowl­edge,” written by Feyerabend in 1968 and published in 1970; all following mentions of Feyerabend in these lectures refer to this work.
  5. See Polanyi 1958; Kuhn [1962] 1970; Merton 1973.
  6. See Oakeshott 1993. For a critical analysis of Oakeshott’s political philosophy, see Watkins 1952.


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