Kuhn And Polanyi: A Conversation
Thomas Kunn and Michael Polanyi

Polanyi: I just wanted to ask you whether you had records of Ramsauer's discussion? It was a very curious thing in connection with the antecedents of the discovery of quantum mechanics. Ramsauer was examining the collisions of slow electrons with molecules. Now he discovered in these experiments that the scattering of faster electrons is greater than that of slower electrons. Faster electrons showed a larger cross-section of collision than the slow ones. And this seemed extremely surprising, and Niels Bohr was very much puzzled by this, and felt that here some new principle was manifested which had not yet been discovered. I don't think he had any idea of what that principle might be, but now we know what happened actually. This was the first experimental manifestation of the wave- nature of matter. . .

Kuhn: . . .this is one of the early applications of de Brogue waves.

Polanyi: The earliest one was I think Elsasser's suggestion of explaining Dymond's experiments on the scattering of electrons by metal surfaces. I think Dymond - if I remember right - was the author's name. Of course Elsasser's paper in Naturwissenschaften was such a decisive step. . . He made that as a contribution to a seminar in Gottingen. And when it came out in Naturwissenschaften, it seemed something completely crazy. But I think all this you know, and probably you know also the story which I have told in part in Personal Knowledge of the fate of de Broglie's first dissertation. . . One of the examiners was I think a crystallographer. There is one point - this is all in Personal Knowledge - that is, I think, moot in history; to what extent it is true, or let us say, precisely true, that de Broglie did have himself some idea that some diffraction patterns might arise. Because he says somewhere that he did have some such ideas, but apparently nobody was aware of that. Certainly not among his examiners. Perhaps he kept that idea to himself. . .

Kuhn: One thing I'd hoped you could help us straighten out. We find ourselves very much confused as yet about the interrelationships between the various scientific institutions in Berlin. . . and also how they relate to the Academy of Sciences - the Prussian Academy.

Polanyi: There were three important centers of physics - the University, the Reichanstalt, and the Technische Hochschule, and finally, the Max Planck or Kaiser Wilhelm-Gesellschaft. But the Kaiser Wilhelm-Gesellschaft had not been organized for physics. I had not yet accepted, in fact had not been invited to take over the institute - it was all on paper. It was on paper that there was some organization which introduced Laue and perhaps also Einstein, but I sin not quite clear. . . Maybe they wanted to pay some salary to Laue because he was short of money. And eventually they did establish this physical institute and, by the time I visited Berlin in - when did the Spanish Civil War start? Silly, - '35, '36, yes - Debye was there; and by that time, of course, physics had been established there. But there was of course in the Kaiser-Wilhelm-Institute for Physical Chemistry - Haber's - for a time a fairly active center of physics, because James Franck was there until 1923, when I was actually put in the place.

Kuhn: Was that the Institute of Dahlem?

Polanyi: Dahlem, yes, that was one of the institutes - that which was described as physical chemistry. Haber was the director, James Franck was one of the members, that is, an independent associate. And then Ladenburg and I were appointed when James Franek left, in a similar position. And Ladenburg of course continued as a physicist. Now the Reichsanstalt was a great institution of physics under Paschen, who - no Rubens. . .Rubens was in his turn succeeded by Nernst whose ambition was to become a physicist - a more high-class occupation. So he left his chair of physical chemistry.

Kuhn: . . .Let me interrupt at that point. Is the attitude in Germany that physics is a more high-class occupation than chemistry?

Polanyi: Well, this was physical chemistry. Physical chemistry did play an ancillary role in my opinion, and it owed its origin to a conjunction of the development of thermodynamics, of the theory of electrolytes, of the gas theory, and certain possibilities which opened the field of the somewhat chemical aspects of these physical discoveries. I think that they were exhausted soon and Nernst probably felt that any major discovery such as his own third law of thermodynamics was already beyond and outside what physical chemistry was as a subject in the universities. I don't think that anything else played a part in it, in Nernst's view. He would not have thought that Emil Fischer, who was a great chemist, would in any way be inferior to a great physicist. But even so perhaps one might think that at that particular time with Planck and Einstein representing physics, perhaps there was a higher level of achievement there in perspective of the centuries.

Kuhn: I quite see how this could strike somebody who really knew what was going on in science and where the most promising leads were. Would people outside knowing less about it - administrators, government figures, or the popular mind - have placed physicists at a higher intellectual level?

Polanyi: Not at the beginning of the century. . . I happened to look through the original documents which were published now on the 50th anniversary of the foundation [of the Kaiser Wilhelm-Gesellschaft]; the foundation took place in 1911. At that time it was Emil Fischer who was the most distinguished scientist and who had the greatest influence in establishing this institution. There was no institute of physics founded, actually. . .

Kuhn: How are the various physical institutions related to each other?

Polanyi: The Academy was a purely honorific institution, founded by Frederick the Great. I never was a member of the Academy, but people who attended the meetings as members found it rather trying because there was a yearly presentation there of very highly specialized inquiries - fields very remote from each other. They considered it, I think, rather as a solemn occasion which duty required them to attend, and I think it was profitable to them. But it had an authority of a kind by virtue of this, and just how it used it at critical times is not something you are at this moment interested in. [Pause]. They excluded Einstein.

Kuhn: But its authority was, you think, exerted on the whole entirely by election, by the right to distribute the honor of membership?

Polanyi: Yes, yes.

Kuhn: There was no core group that had a direct influence regularly in appointments to the university or elsewhere?

Polanyi: No, the appointments I think were always made by consultation between opposite numbers of the same subject in different universities. I should add that the Technische Hochschule in Charlottenburg did not have much distinction in physics until they managed to get Gustav Hertz. Hertz of course was a very good man. He built up a very excellent institute. . . But otherwise these places were quite independent. It's the Reichsanstalt which I am not quite clear about - how it functioned. Because they were involved with quite pedestrian testing of thermometers and such like things - routine matters. At the same time they did maintain a great measure of independent scientific work. Particularly in the low temperature laboratory under Meissner, which I think was certainly the only one in the north of Germany. And they had liquid hydrogen and liquid helium and could carry out experiments - I did some myself - at those temperatures. Then there was Grueneisen there, who was quite distinguished. And another man, who is remembered, of that set is Geiger, author of the Geiger counter. And he, curiously enough, never got much recognition for his now almost proverbially-known thing. Everybody knows what a Geiger counter is and nobody knows anything about Geiger. This is partly due to the fact that he wasn't a man of any great distinction otherwise, and that he was a very bad Nazi, and so people rather forgot him than remembered him, for, that reason too. The most important work was done there by Bothe. . .

Kuhn: Well is there any relation between the Reichsanstalt and the Technische Hochschule?

Polanyi: No, no. The Reichsanstalt was an institution of the Prussian - no, not of the Prussian - of the Reichs-government. The Technische Hochschule was a Prussian institution. There was no connection between the two. The way people met, you probably know, was the seminar every Wednesday. (?)strasse at the university. . . They came from everywhere, from all over Berlin area - we all went there.

Kuhn: How many people were likely to be at a seminar?

Polanyi: About 200, 150 to 200. It was entirely devoted to reporting on papers which were distributed in advance - Laue was the chairman - and he would give a list of papers which had recently been published. That was where I heard for the first time a report by Einstein on Compton's discovery, which he opened by saying: "That first of all shows that light is composed of particles." Then he proceeded to give Debye's explanation for it, which was circulating in private. Compton hadn't published his explanation yet at that time. . .

Kuhn: How was this received?

Polanyi: It was received with, I think, a great appreciation of the event. There was nothing except this remark which referred of course to his own suspicion of the linear momentum of the photon, so that it was completely accepted. There was no question. . . [Schrodinger] spoke in the Physikalische Gesellschaft in 1925 and presented his theory. . . But this struck me. It was very crowded. Lots of people there, from all parts of Berlin, all the institutions. There was a very strong feeling of approval - people thought this was something very good, and in spite of the fact that there was hardly any evidence. All that Schrodinger brought, so far as I remember, was a very rough relationship which he could describe in his terms between the intensities of the Stark effect in some case - so far as I know there wasn't anything else in experiment at that time.

Kuhn: He had the hydrogen eigen values at this point?

Polanyi: This he knew. [His work was not intended as] just a jeu d'esprit, a transcription into new terms. It would have been very nice to say, "well, I mean there are these eigen values and we can understand them in these terms," but it may have been just a metaphor. But that was all. At any rate, I think it would be very important to know, because it is very surprising in view of those who believe that the main criterion of a new theory is that it accounts for experiments which could not be accounted for. . .

Kuhn: Your feeling generally is that there was no great skepticism.

Polanyi: It was very well received, and it is very surprising again that it was so well received, because it had aspects which were horrifying at that time. The electron was supposed to be smeared out in some way. The statistical interpretation was of course at that time not yet discovered, or proposed. . . Not only was it very implausible in this aspect, but it was extremely difficult. I do remember that all during the years immediately following the establishment of quantum mechanics, the professors I knew of in physics were in despair that they would never understand this. It was so strange that they felt completely at sea. They found that their whole professional life was somehow in jeopardy, because they would not understand this. . . But it is not surprising that somebody - whose name I have and will find for you - thought that Heisenberg's paper was a pure formalism and didn't advance the subject.

Kuhn: Most of the people at the meeting of the Physikalische Gesellschaft knew already of the Heisenberg, Born theory.

Polanyi: I think they did, yes. It had come of course a little earlier. It was the talk of the town of the physicists already for some time. But it wasn't immediately manifested - to me, at any rate - I didn't know much about it. Just before the discovery of Heisenberg - about a year or two before that - I talked to Max Born about these problems which seemed to be besetting people. That is the ambiguity of the situation between molecules or particles and waves, particularly of course the puzzling aspect of diffraction of light in these terms. By the way, I was going to say something else but it does occur to me that this was one of the constant preoccupations. Einstein was devising experiments, which then were sometimes tried out in the Reichsanstalt, for producing some tests of what would happen if the particle nature was accentuated, if a single quantum impinges on a scattering center. That, at that time, was very much pursued. Of course, these ideas were abandoned afterwards. They had no importance.

Kuhn: Einstein was at the University at this point, wasn't he?

Polanyi: Einstein, no. This I forgot. There was one single position in the Academy which was a Professorship of the Academy, and was under its auspices. . .Einstein was appointed to this, so far as I remember, from Prague. This was done under Nernst's influence - he took part in the negotiations. . .

Kuhn: One doesn't always find a situation where a man in one institution can have experiments performed at another.

Polanyi: That was purely personal influence and friendship. We were glad to be associated with him and to follow his ideas. He himself didn't make experiments. He did suggest some with a view to this paradox. This was really the paradox which was troubling people so much.

Kuhn: Do you remember how Born felt about the problems of the old quantum theory at this time?

Polanyi: At the time we were talking about the possibilities of resolving difficulties, and he said it must be a younger man who does that, not men like himself - it needed a fresh mind.

Kuhn: Did he feel that the recasting called for was going to go to the heart of things to the extent that it did?

Polanyi: Yes, that's what he meant by "It must be a younger man." And so it did happen. [Polanyi then mentioned the correspondence principle as one approach to a reformulation of quantum theory. It was his impression that it had been suggested by Rubinowicz, not Bohr.] In this connection you have probably heard Kossel's anecdote. He was examining physicists, students for some physics degree, and the student gave a totally absurd reply. He was about to throw him out, and he said at the next moment he realized, "the man may be right!" (laughter) Yes, that was the feeling. It is perhaps for me the most characteristic fact of this period of twenty years that the discovery of light quanta in 1905 was accepted, and very widely, almost universally accepted, although it was very obviously contradicted by such a massive fact as the diffraction of light. . .

Kuhn: But just how many people took the Einstein photon theory seriously in the early days?

Polanyi: . . .Well you see, photo-chemical chemistry was based on the quantum theory of light, and, it had no other possibility then to be based on it. I'm sure I told you the story - you were present when I told the story of Warburg and Einstein.

Kuhn: No, I don't think so.

Polanyi: Well, it's really a story which deserves to be pondered on in various ways. When I went to Berlin in 1920 for two or three years (in the Kaiser Wilhelm Institute for) (physical) Chemistry, I called on people there who were already in established positions - that was, the polite way of doing it. I particularly called on Otto Warburg, who had [once] engaged me as an assistant. I was to have started to work for him on 1 August, 1914. Then the war came and nothing happened, nothing came of it. So six years later I went to see him, and he said how nice it was that I would be there. Also, he said, how good a place it was because there one can always consult people if one doesn't understand something - the people who are the originators of these ideas - and they can tell you exactly what they meant.

So he said that he felt that he had evidence, which incidentally was probably wrong, that four quanta were needed and were actually conjoined in the assimilation of carbon dioxide in the plant. And so he was uneasy about it because the fundamental photochemical law which Einstein had established said there was one quantum. He went to see Einstein, and asked him, "Why do you assume that it is one quantum which participates in the photochemical reaction?" And Einstein said, "Well, that's a lot." So, said Warburg, "now I know why (???)." [laughter.] [Polanyi goes on to discuss the work of Nernst and notes that in 1913 when he first visited Nernst's laboratory, all work was concentrated on measuring specific heats at low temperatures in order to integrate Nernst's equations.] I had a controversy with Nernst. . . Well, since we are on the subject of that milieu, it was in Nernst's seminar [colloquium?] - which happened to be held when I was visiting there for a couple of days from Karlsruhe where I was studying - that I first heard a report on Bohr's theory. F. A. Lindemann, who was a pupil of Nernst's, had been asked by Nernst to report on this new paper. Lindemann put forward the idea that this paper had no significance since from dimensional considerations there was no other way to express Rydberg's constant in terms of the velocity of light, the electric charge and Planck's constant. But Nernst wouldn't have it. He loved Lindemann very much - liked him very much - but he said, "no, no, never, there is something in this theory." And so that was the event of the day when I was there. Now all this shows you, and other stories I could tell you, that quantum theory itself was still in the balance. . . Lindemann then was invited to dinner to meet me, and I will leave away things that are characteristic of him, except a story, a joke, which he made at dinner, which shows you what the situation still was intellectually.

One of Nernst's pupils was engaged to a rich girl, and Lindemann said in his superior way, "Bisser was an (equipartitionist) but now he believes in quanta." Jokes about this controversy were still widespread. There is the story of Einstein, who in Prague had his view on the courtyard of an asylum. And he used to say, "Here are the madmen who do not trouble about quantum theory." So the answer is that one could not say really at the time which part of quantum theory is accepted, for the chemists used it quite early, and low-temperature physics used it, and there was on the whole a great mix-up. Of course, then came Bohr's theory and accentuated all these difficulties very much. . . In 1925 I was lecturing briefly in Copenhagen. Bohr and I talked about discoveries and the like. He said that there is a mystic element in a discovery, and of course he was talking about his own work. Not that it is a mysterious thing, how discoveries are made; but that there is a mystic element in the content of any new discovery. There certainly was in this case. But you see, [with reference to the question of a prevailing attitude in Berlin], many people make this mistake, of rashly thinking that a crisis, a difficulty, can be established unambiguously. There isn't such a thing. You see, the whole question for example, whether or not the statistical interpretation is a problem or not. . .

Kuhn: A quite large number of Hungarians in this period figure very largely in these developments, disproportionally so far as I can tell, to any previous scientific contributions; furthermore, at an absolutely first-rate intellectual level. I wonder what speculatively or not so speculatively could be said to account for this. Also interesting is the fact that so many of them go to the Technische Hochschule in Berlin. What is it about Berlin and about the Technische in particular that makes this the place that the Hungarians are so likely to go? And again, is this a phenomenon about Hungary in general, or is it about the Jewish community in Budapest.

Polanyi: Well, the Jews played a big part in it. The emigration of the Jews - people like myself, Wigner and Neumann and soon - from Hungary, was certainly justified by the better prospects, not only because there was a more active intellectual life in Germany, but because we would have been handicapped in making the grade getting academic appointment in Hungary. But that wasn't by any means decisive. . . I think that the Hungarian participation has been overestimated. The most remarkable intellectual activity - concentrated activity - was in Austria. Austria has the largest number of Nobel Prize winners for population in the world. . .

Kuhn: Some Hungarians who ultimately show up as first-rate theoretical physicists start out as engineers.

Polanyi: This was due to something which can easily be explained. It is rather similar to why I have started as a doctor.

Kuhn: I don't think I knew that.

Polanyi: Yes, I am qualified in medicine. The reason in those cases are a bit different from my own - so I'd best tell you about them. As for them, they were going against their parents' wishes in going to a university and pursuing their intellectual interests. Their parents were rich, business men - von Neumann's was a banker, and Wigner's was a factory manager - and wealthy people who did not think that was sound prospects for their youngsters. . . [to enter an academic career]. And, as to Wigner, I first heard of him through a friend of mine who was technical manager in the factory which was under Wigner's father, who was general manager there. And he told me about the difficulties of this boy - he was just about to leave school and was very gifted. And so I intervened with his parents and I got them to agree that he should come to Berlin.

But he could not have, in these circumstances, started off as a mathematician, a theoretical physicist. And the same applied to Neumann - it was a compromise. You see, he should learn something practical. And so that's why they studied chemistry. . . As to myself, it was an idea that although I had no change of becoming a scientist, at least I would have some form of scientific occupation - being a doctor - and then I could read and perhaps do some work on the side. But it turned out that I became a scientist. Szilard came out and immediately went to the university. One of the Szilard stories which has not been told. . . One day James Franck came to me and said that something very odd has happened. You know how sweet a man he is. "A young man has come and obviously very gifted, but they just can't make him out. He told Planck that he only came here to know the facts. He will make the theories himself." Needless to say, that was Szilard.

Kuhn: Tell me more now - come back from where you were on occasions in the center of the physical group, and talk more about the chemists. . . the extent to which they tried to take this up, the extent to which they were interested in it.

Polanyi: Perhaps that is of some interest. I did realize of course, as one obviously would, that with quantum mechanics, an instrument has been created which in principle would cover reaction velocities which the old quantum theory could not, because it had no theory of probabilities of transition. . . Now then, knowing this and having no real understanding of quantum mechanics as it has only just emerged, I went to Max Born, and I told him what I have just told you, that here is the new knowledge which must give us a theory of chemical reactions, and could he not try to apply it - at least in some simple cases. He asked me what cases, what laws, I would like to derive and explain. My answer was that there is a very remarkable fact that single atoms react much faster with a molecule than molecules react with each other. For example a sodium atom would react instantaneously with a chlorine molecule. And he said "That's impossible. This is far too complicated a problem - sodium and chlorine - I mean, how should I do that?" That is he couldn't, because he didn't envisage the three-electron problem as sufficient. . . But a little afterwards - not very long, in 1928 or '29 came London's theory, which used really Wigner's formula for the three electron problem. Wigner had overlooked that, and London gave that theory a form which is now used for explaining chemical reactions. . . What I thought was interesting was that it was possible to specify certain things which must be easily understandable by the new theory because they are by nature fundamental. . . So that what Born said was obviously wrong somehow - I knew that. Of course, I couldn't do it properly myself then. But there is the difference between the physicist and the chemist.

Kuhn: Well, were the chemists generally fairly close to the physicists? This story of your own I take it is probably not typical of the chemists as a group. To what extent did they hear of this? How early were the attempts to handle the valence problems?

Polanyi: The valence problem was attacked here [in Berkeley], and the people here will tell you exactly what the relation was, of their work, with the Heitler-London theory of 1928. This was the first time that a (whole polar bond) theory was given in Germany, one which was immediately convincing, and widely accepted. Until then, as I told you the other day, the inclination was to assume that the forces are electric, and this inclination was elaborated by Kossel in his, at the time, extremely popular theory. It was a very widely responded to by physicists in particular and supported by them. . . There was, in 1919, an accumulation of evidence that all the forces between molecules, atoms and so on are electric. It all started with the discovery of dipole, and then was followed up by the quadrupole discovery of Keesom (?), the Debye theory of quadrupoles acting on polarizable atoms, and the heteropolar theory of ions by Born, and finally fifth, Kossel's mistaken theory of valence.

Of this dominant conception about the nature of things - the nature of forces, molecular forces - one of the casualties was my theory of adsorption. I had assumed the character of the forces of adsorption, similar to those of gravitation, uninfluenced by the presence of other particles in the field and completely additive no compensation, no saturation such as electric forces naturally involve. . . I made up the original theory of adsorption in 1916, and it's still in the balance. Now people are inclined to accept it, but it's still in the balance and it is very interesting. I think I mentioned it to you, but it's an interesting story because the theory I think is perfectly right. It's not very accurate for certain reasons which are intrinsic, but it's the right approach, whereas the Langmuir theory, which is current, is quite false and can be shown to be false. Now the really interesting point, returning to this general opinion about the nature of forces, is that I could have proposed these forces in my ignorance of all these things, I daresay I could not have heard of them in 1916 in the hospital where I wrote my thesis during the war.

I assumed these forces, not thinking about it any further, and it was accepted by non-physicists who were ignorant as I was. I was invited to speak on that in 1921 in the Haber seminar, colloquium it was called. Actually these seminars are not seminars but colloquium - I mix up the terminology. Einstein was invited to view this problematic figure, namely myself, and also a number of people from bio-chemistry and bio-physics who were interested in adsorption. The upshot of it was that the biochemists and the ignorant people were deeply impressed by the theory; whereas Einstein - he didn't say it to me, but to someone else, thought it was an amateurish thing to use these forces which don't exist and can't exist. Well, in fact the forces do exist, and they were discovered then in 1929 by London in the now current theory of cohesion, and then at my request London examined it and found that there are gravitation (ions) exactly as I had suggested there were. But this remained an obstacle.

You see the people concerned with adsorption are not first-rate people and their minds don't work very fast, and since they had heard that this was wrong, fifty years ago or thirty years ago, they continued to believe it, and they have not taken much notice of the changes. However, this is interesting I think because here was something which quantum mechanics alone made possible. . . Something which seemed to be utterly absurd was in fact revealed as being completely right. That's happened between 1919 and 1929. Supposing I am right, and particularly in my view about the theory of Langmuir. It is a case in which people are so attracted by three reasons, all of which one could say are extremely plausible. Let's see, elegance of the form, the interest it takes in the (isotome), the fact that it can be applied to plane surfaces instead of these porous substances. These are three reasons which make this a highly attractive theory. Both these reasons are wrong. But, as I say, it is an interesting case in the question between plausibility and truth.

Kuhn: Let me ask you another silly question. This is obviously in a sense totally off the question of the quantum mechanics picture, but it is an issue of some interest to me. You went to talk about it or you may want me to turn off the recorder which I'd be glad to do. What got you out of the sciences?

Polanyi: Well, that's really a very simple matter. What happened was that I started getting interested in other things, and finally spent a good deal of time pursuing these other matters. I must have started that in '28. We had a seminar in Berlin with Marschak, whom I met yesterday here. He was our economics mentor. He was professor at Yale and now at UCLA. . . And the members were Szilard and Neumann and myself, and two or three other people. At that time we were trying to train ourselves in economics and to understand the Russian phenomenon. . . I always intended to give up science at one stage or another and to do something else. . . I read H. G. Wells as a youngster and things like that. He said there would be a great war. I thought that I would make my discoveries in science before the great war and afterwards I would go on and do something in philosophy of science. And actually when I wrote my theory of adsorption I thought I had made a great discovery. I had made a discovery, but not a very great one. And so that didn't help me to establish myself definitely as a scientist. But there was a point at which I was about to leave science altogether.

This was towards the end of the first world war. I intended to take up a position in the government. I had achieved a certain reputation in the first revolutionary government and was at a fairly high level in the hierarchy. Then of course the communists came and overthrew the government. I left all that and went to the university. Then I was thrown out from the university, and so one thing followed another. But I had already then this idea, and I wrote reams and reams of that manuscript which I have thrown away. As a matter of fact, what happened was that I was invited in 1937 [1947] to give the Gifford lectures and that's supposed to be something exceptional. And so I went to the university authorities and asked them, should I accept this or refuse it. I didn't really know, because surely I can't do this job properly if I am going to conduct my laboratory. . . So I had many friends in the university who heard about this and they thought that it would be an occasion for giving me a chair, a sort of professor-at-large chair, which they did. . . I found myself at the age of 57 starting on a new career which required a tremendous amount of reading and a very great deal of effort in thought, so that I did not have any occasion to continue my interest in physical chemistry.

Kuhn: You talk about the seminar in '28 and the real transition in '47.

Polanyi: I think I first wrote about matters of this kind in '35, in fact I wrote a paper on the soviet economics which I think is probably the first paper - so I am told by experts - in which an attempt was made at assessing the product of soviet industry in prices of the western market. And I came to conclusions which are rather surprising. It is still remembered. But that was the first time that something took away quite an appreciable amount of time and caused my delay in publishing some things which otherwise would bear my name instead of other people's. So by the time I was already leaning in that way.

Kuhn: How did you happen to get involved in that paper?

Polanyi: Well this was just an interest, by visiting Russia. I had been there about four times and the '28 thing, the seminar in '28, was directed towards this particular thing. I still have the opening address for that '28 venture of what the use was of thinking of matters of this kind. . . Then I was asked to write a review. And I wrote an article on the soviet civilization. . . It was a cumulative effect, but there were other reasons as well. I had never looked forward with pleasure to the idea of being a scientist in old we, the examples which I found were disheartening, old people trying to compete with young people. And I would rather be out of that race when I am no longer really of it. I was particularly frightened by Haber's continuous perturbation - just trying to make some big discoveries so that he should justify his existence, and he always felt he hadn't made any big discoveries. On the whole I think that the academic profession, and that of the scientist particularly, is very arduous.

Every person who enters a profession, whatever it is, has to go through a phase when he recognizes his limits so that he should be able to work up to those limits and not try to work beyond them. And that has always been. But somehow in science it doesn't seem ever to cease to be painful. I cite you my little story of my days with X-rays that answers some of your questions about chemists, not in this connection of quantum mechanics. This other story is more to the point. There is one thing which I think is worth remembering in this whole period. Namely that the moral and human level of the natural sciences was very different in different parts. The physicists really did in that respect make very marked progress under the influence of Planck, Bohr, and Einstein. Not so much Rutherford. But James Franck. A kind of nobility was established there. Courteous, firm, and. in many ways quite different from what it had been in the previous generation. I don't know what it was like in physics, but I do know that in chemistry it was very different. We were actually more envious and the conflicts and polemics were bitter and unenlightening.

Kuhn: Were these often polemics over priorities?

Polanyi: Polemics over priorities also existed, oh yes. But these things were - Laue was also a man of noble character, and so is Otto Hahn and Otto Hahn of course and Lise Meitner were of course the admirers of great men who were either their contemporaries or somewhat older. And this is really the basis today of these Pugwash Conferences of physicists.

Kuhn: I would like to let you finish out this line which interests me a good deal.

Polanyi: The confidence, which is such an important factor in these international meetings which the physicists dominate is really still I think derived from the influence of these people who transformed the atmosphere of the association of physicists. And I think that the chemists don't have the same possibilities.

Kuhn: I'm curious and I don't really have many ideas on it, about the extent to which this is a transformation of the tradition in physics as against the extent to which it may be a long-standing difference between physicists and chemists. Because there are a lot of differences, I needn't tell you, between the two professional groups. They've showed up in occasional international episodes as to who might be members. The American Chemical Society refused to accept membership applications from Irene Joliot Curie - it shows up often. I think examinations of the relative political opinions of the two groups get quite different results. And I take it that it has something to do with the fact that chemistry has throughout its existence had such close relations with practical life. . . I wonder to what extent this - the fact that physics has been traditionally a more academic subject than chemistry - may be involved at the root of this difference. Do you suppose that has something to do with it?

Polanyi: I shouldn't have thought so, no. But I cannot explain it. I would explain it if I were to try, in terms of persons who had such an influence. There were other people who were not exercising such influence. Rutherford was very difficult and he wounded and caused much unhappiness in my predecessor, who was a colleague of his - (Laporte) told me often about it. I don't know, I don't know what the reason is. I know that Emil Fischer who was certainly one of the greatest chemists ever, conducted his laboratory in a way which seemed completely immoral and inhuman. One of his assistants, who became a distinguished chemist after Fischer's death, thought that Fischer used to farm out problems to his assistants, and then not allow them to discuss them between themselves. And he would give the same question to different people, so as to check up on them, if they were faking their results. And consequently producing an unbreatheable atmosphere, and totally different from anything one met in Gottingen in the great flowering of thought and ideas among the physicists. I must say I never heard of particularly intellectual atmosphere being present among the chemists, however important their work was. And this has been often observed, that chemists seem never to be in their own groups.