Reprinted with permission from Serving the Reich: The Struggle for the Soul of Physics under Hitler, by Philip Ball. The University of Chicago Press. Copyright © 2014, Philip Ball. All rights reserved.

Anti-Semitism did not just deprive German physics of some of its most valuable researchers. It also threatened to prescribe what kind of physics one could and could not do. For Nazi ideology was not merely a question of who should be allowed to live and work freely in the German state—like a virus, it worked its way into the very fabric of intellectual life. Shortly after the boycott of Jewish businesses at the start of April 1933, the Nazified German Students Association declared that literature should be cleansed of the “un-German spirit”, resulting on 10 May in the ritualistic burning of tens of thousands of books marred by Jewish intellectualism. These included works by Sigmund Freud, Bertolt Brecht, Karl Marx, Stefan Zweig and Walter Benjamin: books full of corrupt, unthinkable ideas. Into some of these pyres, baying students threw the books of Albert Einstein.

It was one thing to say that art was decadent—that its elitist abstraction or lurid imagery would lead people astray. And the “depraved” sexuality saturating the pages of Freud’s works was self-evidently contaminating. But how could a scientific theory be objectionable? How could one even develop a pseudo-moralistic position on a notion that was objectively right or wrong? Besides, hadn’t Einstein’s relativity been proven? What did it even mean to say that science could be subverted by the “Jewish spirit”?

It would be absurd, of course, to suppose that most of the book-burners had given these questions a moment’s thought. The simple fact was that Einstein was a prominent Jew, and his thoughts therefore fit for the bonfire. But Einstein’s theory was attacked on racial grounds. This assault came not by asinine ideologues in the party whose knowledge of science extended no further than a belief in fairy tales about “cosmic ice,” nor from individuals on the scientific fringe seeking official approval and support. It was orchestrated by two Nobel laureates in physics, who devised a full-blown thesis (it can’t be dignified by calling it a theory) on how stereotypical racial features are exhibited in scientific thinking. They were Philipp Lenard and Johannes Stark, and they wanted to become the new Führers of German physics.

The story is ugly, sad, at times comic. It illustrates the complicated interactions between science and politics in Nazi Germany, for although one might expect the “Aryan physics” (Deutsche Physik) of Stark and Lenard to have been welcomed by the National Socialists, its reception in official circles was decidedly mixed, and in the end it was ignored. The case of Deutsche Physik reveals how much of what went on in the Nazi state depended on how you played your cards rather than on what sort of hand you held. It shows how the German scientists’ pretensions of being “apolitical” did not prevent politics from infecting scientific ideas themselves, and almost overwhelming them. Perhaps most importantly, the story explodes the comforting myth that science offers insulation against profound irrationality and extremism.

Against relativity

Lenard’s anti-Semitism festered for years before the Nazi era, and as was the case with many other haters of Jews his antipathy was fuelled by a sense of exclusion and injustice. The fact is that Lenard was a rather unremarkable man: an excellent experimental scientist in his heyday, but of limited intellectual depth, and emotionally and imaginatively stunted. When circumstances contrived to carry him further than his talents should have permitted, he was forced to attribute his shortcomings to the deceptions and foolishness of others. This combination of prestige and deluded self-image is invariably poisonous. There is no better example than Lenard to show that a Nobel Prize is no guarantee of wisdom, humanity or greatness of any sort, and that, strange as it may seem, the award can occasionally provoke feelings of inadequacy.

Lenard was given the prize in 1905 for his studies of cathode rays, the “radiation” emitted from hot metals. They were manifested as a glow that emerged from a negatively charged metal plate (cathode) inside a sealed, evacuated “cathode-ray tube” and made its way to a positively charged plate. Directed on to the glass walls of the tube – or as researchers discovered, on to sheets of particular minerals – the cathode rays stimulated bright fluorescence. Like his mentor Heinrich Hertz at the University of Bonn, Lenard at first believed these rays to be fluctuations in the ether—like light, as it was then conceptualized. But while J. J. Thomson, director of the Cavendish Laboratory in Cambridge, noted in 1897 that this was “the almost unanimous opinion of German physicists”, he had results that implied otherwise. Thomson showed that cathode rays have negative electric charge, being deflected by electric and magnetic fields, and he concluded that they were in fact streams of particles. They were given the name proposed some years earlier by the Irish physicist George Johnstone Stoney for the smallest possible unit of electrical charge: electrons. As Lenard put it, electrons are the quanta of electricity.

Lenard discovered how to enable cathode rays to escape from the vacuum chamber in which they were created, so that they could be examined more closely. He also investigated the photoelectric effect the expulsion of electrons from metals irradiated with ultraviolet light – and discovered that the energy of these electrons did not depend on the intensity of the light but only on its wavelength. When Einstein explained this result in 1905 in terms of Planck’s quantum hypothesis, Lenard felt that his discovery had been stolen. That bitterness deepened when Einstein was awarded the 1921 Nobel Prize in Physics for his work on the photoelectric effect. This was not Lenard’s only early source of resentment. He felt that he should have discovered X-rays before Wilhelm Röntgen, and was sure that he would have done so if the jealousies of senior professors had not denied him better opportunities. And hadn’t he offered Röntgen advice about constructing the cathode-ray tube used for this discovery, which Röntgen didn’t even have the good grace to acknowledge?

But if the German professors selfishly and unjustly hid their intellectual debts, the English were worse. Thomson should have given him more credit for his work on the photoelectric effect, for instance. This, however, was no more than one could expect from a nation of vulgar materialists—Lenard would surely have sympathy with Napoleon’s remark about shopkeepers—who knew nothing of the heroic, selfless Germanic Kultur. James Franck later claimed that, when he was fighting at the front in the First World War, Lenard wrote to him expressing his hope that the defeat of the English would make amends for their never having cited him decently.

An operation for an illness of the lymph nodes around 1907 left Lenard less able to work, and contributed to his difficulties in keeping up with the latest developments in physics. Because he was not mathematically adept, he could not get to grips with relativity or quantum theory. As a result, he decided they were nonsense. The fact that this nonsense—whose premier architect was Einstein—was being accepted and acclaimed by physicists all over the world must therefore be the result of a conspiracy. And conspiracies and cabals were the specialty of Jews.

Einstein was the embodiment of all that Lenard detested. Where Lenard was a militaristic nationalist, Einstein was a pacifistic internationalist. Einstein was feted everywhere, while Lenard’s great merits seemed to have been forgotten. Worse, Einstein was celebrated most of all in England! And he hawked a brand of theoretical physics that frankly baffled Lenard. How convenient, then, that Einstein was a Jew, so that all of these deplorable traits could be labeled Semitic. (Of course, many of Einstein’s supporters were not Jewish, but as we shall see, Lenard and his ilk later contrived to make them “honorary Jews”.) Lenard decided that relativity was a “Jewish fraud” and that anything important in the theory had been discovered already by “Aryans.”1

Lenard criticized the theory of relativity as early as 1910, but it was not until the 1920s that his attacks began to incorporate explicitly racial elements. He started to develop the notion that there was a Jewish way of doing science, which involved spinning webs of abstract theory that lacked any roots in the firm and fertile soil of experimental work. The Jews, he said, turn debates about objective questions into personal disputes. Ironically, this supposed preference of “Aryans” for hale and hearty experiment went hand in hand with the kind of Romantic mysticism that infuses Nazi philosophy, such as it is. Lenard approved of the animistic Naturphilosophie of Goethe and Schelling, the belief in a spirit that animated all of nature. This pervasive soul of nature was the wellspring of science itself—and only Aryans, said Lenard, understood this: “It was precisely the yearning of Nordic man to investigate a hypothetical interconnectedness in nature which was the origin of natural science.”

Lenard persisted in believing in the light-bearing ether that Einstein had rejected, saying cryptically that this elusive medium “seems already to indicate the limits of the comprehensible”. He lamented the encroachment of technology in modern life: an expression, he said, of the kind of materialism that infected both Communism and the Jewish spirit, the twin enemies of German greatness. Materialistic natural science had eclipsed the “spiritual sciences,” giving rise to the “arrogant delusion“ that humankind can achieve the “mastery of nature.” “That influence has been strengthened by the all-corrupting foreign spirit permeating physics and mathematics, “ he wrote—“foreign“ here meaning, of course, Jewish.

The enthusiasm of the Nazi regime for this brand of mysticism and pseudoscience has been well documented, although perhaps not enough has yet been made of the resonances between fascism, Naturphilosophie, the cultish mysticism of Rudolf Steiner2 and anthroposophy, and the cozy certainties of some New Age beliefs. Reified worship of nature (as opposed to respect for it) has always teetered on the brink of a fundamentally fascist ideology. Several Nazi leaders, including Hitler and Himmler, endorsed the ridiculous “cosmic ice“ theory of Austrian engineer Hans Hörbinger, which asserted that ice is the basic ingredient of the universe. Lenard’s musings on racial science and the “spirit of nature” do not really rise above this level—they show that, even by the time of his Nobel award, he had nothing more significant to contribute to science, but had indeed become its opponent.

When, in the 1920s, Einstein began to experience racially motivated criticism and abuse in the German popular and academic press, Lenard joined in gleefully. At a meeting of the Society of German Scientists and Physicians in Bad Nauheim in September 1920, Einstein and Lenard were pitched head to head in a debate about relativity.

This confrontation followed an attack on Einstein at a public meeting held in Berlin the previous month, allegedly organized by the Working Group of German Scientists for the Preservation of Pure Science. There was in fact no such body, it having been concocted for the purpose by one Paul Weyland, a far-right fantasist without any real scientific training, who deplored Einstein’s theory on the sort of “common sense” grounds that cranks still choose to employ today. Weyland presaged this event with a letter in the Berlin newspaper Tägliche Rundschau recycling old accusations that Einstein had plagiarized the insights of other scientists. The meeting itself took place in the capacious Berlin Philharmonic, where Weyland’s rant was accompanied by the distribution of anti-Semitic pamphlets and swastika lapel pins.

Weyland had announced that his lecture was the first in a series of twenty that would lay bare the deceptions of relativity. In the event, only one other followed, by the equally anti-Semitic applied physicist Ludwig Glaser. The whole shabby affair aroused wide indignation: the letters of support for Einstein that appeared subse­quently in the pages of the Berlin press were by no means all from his colleagues. Planck wrote to Einstein characterizing Weyland’s assault as “scarcely believable filth.” He and others feared that such things would drive Einstein to emigrate from Germany.

Einstein did remain in Berlin, but he was evidently unsettled. He went himself to Weyland’s meeting and, somewhat against his instincts and with rare misjudgment, he decided to respond publicly to the attack. His letter in the Berliner Tageblatt did at least contain a dash of humor to undercut the risk of pomposity, being titled “My Answer to the Anti-Relativity Theoretical Co. Ltd.” He admitted that the feeble criticisms of his theory did not really warrant a reply, but also pointed out that the real complaint of Weyland and his acolytes was that Einstein was “a Jew of liberal international bent.” Einstein also mentioned Lenard (who supported Weyland), saying “I admire Lenard as a master of experimental physics [but] his objections to the general theory of relativity are so superficial that I had not deemed it necessary until now to reply to them in detail.”

The exchange at Bad Nauheim was no more illuminating, and certainly no more conciliatory. After the Berlin affair, this Einstein Debatte was widely anticipated, and the hall in which it took place was packed to the galleries, not just with scientists but with journalists and curious onlookers—and Weyland—who must have been thor­oughly bored and mystified by the four hours of technical talks that preceded it.

Accounts of the debate differ. Some newspapers reported that it was conducted calmly and objectively, but others stated that Planck, who as the society’s president was obliged to be the moderator, was forced on several occasions to intervene to prevent hecklers from interrupting Einstein. In any event, neither Einstein nor Lenard was pleased with the outcome. Einstein was highly agitated afterwards—he later admitted his regrets at “losing myself in such deep humor­lessness”—and his wife Elsa seems to have suffered something of a nervous breakdown. For his part, Lenard felt compelled to resign from the DPG in protest at the event, and he fixed a sign outside his office at Heidelberg announcing that the society’s members were not welcome within.

Physics for Hitler

Lenard was not the only influential scientist in the anti-Einstein camp. In 1919 the Nobel Prize in Physics was awarded to Johannes Stark for his discovery of the effect of electric fields on the energies of photons emitted from atoms as electrons jump between their quantum orbits.3 In an electric field, the energy of an electron in a particular orbit splits into a whole series of different energies: rungs of a new quantized energy ladder. Stark’s discovery of this effect was of some importance, since it revealed a further level of quantum granularity in the structure of the atom. Nevertheless, the 1919 award was perhaps one of the Nobel Committee’s least auspicious decisions, for it inflated Stark’s already ponderous sense of self-importance and entitlement.

Stark’s situation was so close to Lenard’s that it is no wonder the two men forged a firm alliance. Like Lenard, Stark was an experimentalist befuddled by the mathematical complexity that had recently entered physics. He was another extreme nationalist whose right-wing views had been hardened by the First World War. He too felt that Einstein had stolen his ideas, this time over the quantum-mechanical description of light-driven chemical reactions. (Stark never in fact fully accepted quantum theory, even though an understanding of the “Stark effect” depended on it.) And being a mediocrity who struck lucky, he found himself being passed over for academic appointments to which he was convinced he had the best claim. He attributed this to the self-interest of a “Jewish and pro-Semitic circle” centered on the (decidedly Aryan) Planck and Sommerfeld, the latter being the alleged cabal’s “enterprising business manager.”4 This circle included most of Sommerfeld’s students, not least Peter Debye, who was given the professorship at Göttingen in 1914 for which Stark had applied. Lenard’s and Stark’s enemies suggested that their definition of “Jewish science” was more or less anything that the two physicists could not understand, and that they placed in the “Jewish cabal” anyone who threatened to outclass them scientifically. But Einstein was undoubtedly perceived as the ringleader of the whole affair.

By 1922 the situation had deteriorated to such a degree that Einstein declined to speak at a session of the Society of German Scientists and Physicians in Leipzig, fearing that his life might be in danger. This wasn’t paranoia. In June the Jewish foreign minister of the Weimar government Walther Rathenau, who Einstein knew well, was assassinated in Berlin by two ultra-nationalist army officers. Lenard had refused to lower the flag of his institute at Heidelberg as a mark of respect for the murdered minister, and as a result he had been dragged from his laboratory by an angry mob of students. Lenard narrowly escaped being thrown into the River Neckar, but the distressing ex­perience only deepened his anti-Semitism. When he was reprimanded by the university, he announced his resignation in disgust. He soon withdrew it when he discovered that the shortlist for his replacement consisted of two “non-Aryans”—James Franck and Gustav Hertz,5 who had won the Nobel Prize together in 1925—and an experimen­talist sympathetic to England, Hans Geiger, who had worked with Rutherford in Manchester. In the end Lenard clung on at Heidelberg until 1929, when he was replaced by Walther Bothe. Lenard’s colleagues made Bothe’s life so miserable, however, that he moved to the Kaiser Wilhelm Institute for Medical Research in Heidelberg. Lenard so dominated the physics institute at Heidelberg that it was named after him in 1935.

Laue spoke on relativity in Einstein’s place at the 1922 conference, earning the abiding enmity of the “Aryan physicists.” His audience was supplied with pamphlets distributed by Stark decrying this “Jewish theory.”

When, in the following year, the National Socialists took up arms in Munich to openly challenge the complacent decadence of the Weimar government and free Germany from the Jewish stranglehold, Lenard and Stark recognized a kindred spirit and a hope for the future. In May 1924 they wrote an article called “The Hitler spirit and science.” Hitler and his comrades, they said, “appear to us as God’s gifts from times of old when races were purer, people were greater, and minds were less deluded…He is here. He has revealed himself as the Führer of the sincere. We shall follow him. The Nazi leader noted this pledge of support, and he and Rudolf Hess visited Lenard at home in 1926.”

Stark was in fact the author of his own exclusion from the academic community. Slighted by the opposition from his colleagues at Würzburg to his acceptance of a Habilitation thesis from his student Ludwig Glaser—Glaser’s study of the optical properties of porcelain was regarded as mere engineering, not true science—Stark petulantly resigned from his professorship in 1922. He set up a private laboratory in a nearby disused porcelain factory, using the money from his Nobel Prize to fund this industrial venture (which was against the Nobel Foundation’s rules). At the same time he channeled his resentment against academia generally and theoretical physics in particular into a book called The Present Crisis in German Physics. Glaser, as we saw, had already embraced his mentor’s philosophy and became a vocal propagandist of Aryan physics. He was appointed assistant to the undistinguished engineer Wilhelm Müller, Sommerfeld’s politically favored successor at Munich (see page 103). But Glaser was so virulently racist that he became a liability and was subsequently moved out of harm’s way to the fringes of the Reich—Poland and then Prague—where he thankfully fades from history.

By the late 1920s Stark’s porcelain venture had failed, and he tried to regain an academic post but was repeatedly passed over in favor of more able candidates. When Sommerfeld opposed his application for a professorship at Munich, this confirmed in Stark’s mind that Sommerfeld was a spider in the Jewish web.

How Aryans created science

For Stark and Lenard, the canker at the core of German physics was not merely the nepotism of the Jews and their lackeys, nor the obscure theories and unpatriotic internationalism of Einstein. The fundamental problem lay with a foreign and degenerate approach to science itself. The popular notion that science has a universal nature and spirit, they said, is quite wrong. In an article titled “National Socialism and Science”, Stark wrote in 1934 that science, like any other creative activity, “is conditioned by the spiritual and characterological endowments of its practitioners”. Jews did science differently from true Germans. Echoing Lenard’s fantasy, Stark claimed that while Aryans preferred to pursue an experimental physics rooted in tangible reality, the Jews wove webs of abstruse theory disconnected from experience. “Respect for facts and aptitude for exact observation”, he wrote, reside in the Nordic race. The spirit of the German enables him to observe things outside himself exactly as they are, without the inter­polation of his own ideas and wishes, and his body does not shrink from the effort which the investigation of nature demands of him. The German’s love of nature and his aptitude for natural science are based on this endowment. Thus it is understandable that natural science is overwhelmingly a creation of the Nordic–Germanic blood compo­nent of the Aryan peoples.

Just look, Stark implores his readers, at all the great scientists whose portraits are presented in Lenard’s Grosse Naturforscher (Great Investigators of Nature; 1929): nearly all have “Nordic–Germanic” features (even, apparently, Italians like Galileo).

In contrast, the Jewish spirit in science “is focused upon its own ego, its own conception, and its self-interest”. The Jew is innately driven to “mix facts and imputations topsy-turvy in the endeavor to secure the court decision he desires”. Of course, the Jew can imitate the Nordic style to produce occasional noteworthy results, but not “authentic creative work”. The Jew suppresses facts that don’t suit him, and turns theory into dogma. He is a masterly self-publicist, courting and seducing the press and the public – just look at Einstein.

What Germany needs, then, is a truly German, “Aryan physics” (Deutsche Physik) that rejects the overly mathematical fabulations of relativistic physics in favor of a rigorously experimental approach. And in a formula calculated to ingratiate him to the new leaders, Stark adds that “The scientist does not exist only for himself or even for his science. Rather, in his work he must serve the nation first and foremost. For these reasons, the leading scientific positions in the National Socialist state are to be occupied not by elements alien to the Volk but only by nationally conscious German men.”

While the Aryan physicists were incapable of mounting a credible assault on Einstein’s relativity in scientific terms, Deutsche Physik offered a new line of attack: relativity threatened to undermine the very essence of the Germanic world view. Incorrectly claiming that rela­tivity “sets aside the concept of energy”, the Nazi mathematician Bruno Thüring asserted that in this aspect one can see “something concerning the soul, world-feeling, attitudes and racial dispositions”. Einstein, he said, is not the successor of Copernicus, Galileo, Kepler (the canonical Nordic–Germanic scientist) and Newton, but their “determined opponent”:

“His theory is not the keystone of a development, but a declaration of total war, waged with the purpose of destroying what lies at the basis of this development, namely, the world view of German man . . . This theory could have blossomed and flourished nowhere else but in the soil of Marxism, whose scientific expression it is, in a manner analogous to that of cubism in the plastic arts and the unmelodies and unharmonic atonality in the music of the last several years [“degenerate science”!]. Thus, in its consequences the theory of relativity appears to be less a scientific than a political problem.”

These ideas were noted and initially welcomed by Hitler. “That which is called the crisis of science”, he wrote, “is nothing more than that the gentlemen are beginning to see on their own how they have gotten on to the wrong track with their objectivity and autonomy. The simple question that precedes every scientific enterprise is: who is it who wants to know something, who is it who wants to orient himself in the world around him? It follows necessarily that there can only be the science of a particular type of humanity and of a particular age. There is very likely a Nordic science, and a National Socialist science, which are bound to be opposed to the Liberal–Jewish science, which, indeed, is no longer fulfilling its function anywhere, but is in the process of nullifying itself.”

Such declarations can scarcely leave one with an impression that the Nazis had much sympathy for – or understanding of – true science. But neither should they be read as some kind of official doctrine that guided the Nazi government’s policy on scientific research. Frequently, Hitler’s grandiose statements – on this or other matters – had as little real influence on the way affairs were conducted at the daily, prosaic level as do the proclamations of the Pope on the dealings of a local Catholic church. Indeed, Hitler purposely maintained a distance between his own views and edicts and their practical implementation. The actual response of the National Socialist authorities to Deutsche Physik was not uncritical acceptance but something rather more complex.

Deutsche Physik under the Nazis

The anti-Einstein activism of Stark, Lenard and their fellow travellers continued through the early 1930s. In 1931 a hundred scientists and philosophers contributed to a volume denouncing Einstein and his theories. A few supporters, such as Laue and Walther Nernst, defended him publicly against such onslaughts. But typically his champions would stick up for his theories while avoiding the delicate “political” matter of his Jewishness.

When Hitler became Reich chancellor, the Deutsche Physiker must have felt that their moment had come. And so it seemed – at first. Stark was made president of the prestigious Physical and Technical Institute of the German Reich (PTR) in Berlin in 1933, giving him new pretensions of power. He announced that the PTR would thence­forth take charge of all German scientific periodicals, and at the meeting of the DPG in Würzburg in September 1933 it seemed to Laue that Stark was trying to anoint himself Führer of all German physics. In his opening address as chairman, Laue publicly challenged the Aryan physicists by making an implicit comparison between the theory of relativity and the condemnation of Galileo’s Copernican theory by the Catholic Church. Invoking the (apocryphal) story that Galileo had muttered “eppur si muove” (“still [the earth] moves”) as he rose after kneeling to hear his sentence, Laue made it clear that Einstein’s theory would remain true whatever his detractors might assert.

Here once more, Laue’s courage in defying Nazi demagoguery and interference was very rare among the physicists. “To all of us minor figures”, Paul Ewald wrote later, “the very existence of a man of Laue’s stature and bearing was an enormous comfort.” His resistance was not without a certain panache: he was said never to go out of doors without carrying a parcel under each arm, since that gave him an excuse not to give the obligatory Hitler salute in greeting. Laue was one of the very few scientists in prominent positions to move beyond private grumbles and little acts of defiance into open admission of his contempt for the Nazis. And unlike Planck, he came to recognize that scientists could not remain “apolitical”. In 1933 he was among those who chided Einstein for his activism, warning him that “political battles call for different methods and purposes from scientific research” and that as a result scientists rarely fared well in that arena. But by and by he saw that one could not simply stand aloof from National Socialism. Indeed, he implied to Einstein that he stayed in Germany only because his loathing of the Nazis made him desperate to see their downfall. “I hate them so much I must be close to them”, he told Einstein during a visit to the United States in 1937. “I have to go back.” After the war, James Franck said that Laue “was not a daredevil, blinded against peril by vitality and good nerves; he was rather a sensitive and even a nervous man who never under­estimated the risk he ran in opposing Nazidom. He was forced into this line of conduct because he could bear the danger thus incurred better than he could have borne passive acceptance of a government whose immorality and cruelty he despised.”

When we hear it said in defense of German physicists that not all men can be heroes, we should bear this remark in mind: it is not a matter of how strong your backbone is, but of how much your personal sense of morality can tolerate.

Thanks in considerable measure to Laue – but perhaps still more to infighting among the National Socialists – Stark’s attempt to rule German physics came to nothing. He could, however, at least impose his views on the PTR, where he instigated the Führer principle and sacked all Jews from the advisory committee. The following year he was appointed president of the German Research Foundation, which controlled much of the funding for science, and he promptly withdrew funds for work in theoretical physics. (Because of a shift of political power, Stark fell from grace and was forced to retire from this post two years later, whereupon funds for theoretical physics were restored.)

Prompted by Goebbels’ Ministry of Propaganda, in the summer of 1934 Stark wrote to all eleven of his fellow Nobel laureates in Germany asking them to sign a letter declaring that:

“In Adolf Hitler we German natural researchers perceive and admire the savior and leader of the German people. Under his protection and encouragement, our scientific work will serve the German people and increase German esteem in the world.”

This quasi-religious statement found no takers, although the refusals were carefully crafted. Heisenberg, for example, told Stark that he agreed with the sentiments but felt it inappropriate for scientists to make public pronouncements on political matters. That was not just a convenient excuse but a genuine statement of belief, which cut both ways: Heisenberg seemed to apply it equally to Stark’s infantile gesture and to questions of moral responsibility.

Stark and Lenard fretted about the KWG, which seemed to them to be decidedly lax about expelling its Jewish members – no doubt, they were convinced, because it was dominated by an Einsteinian cabal. “From the beginning,” Lenard wrote in 1936, “it was a Jewish monstrosity with the purpose, entirely unknown to the emperor and his advisers, of enabling Jews to buy themselves respectability and of bringing Jews and their friends and similar spirits into comfortable and influential positions as ‘researchers.’” Starting now to ramble inanely, Lenard proclaimed that the society’s president Planck was “so ignorant about race that he took Einstein to be a real German,” doubtless because of the many theologians and pastors in Planck’s family and their misguided respect for the Old Testament.

Stark and Lenard had hoped to set the society straight when Planck’s first term of office came to an end in 1933: “to make something sensible of this completely Jewish business”, wrote Stark, “which, as a start, must simply be pulled to pieces”. But Planck did not retire; he stayed for a second term of office. When that was due to expire in March 1936, Stark felt sure he would be called upon as the new president. Inexplicably, he wasn’t. (Bernhard Rust, who was now able to dictate the society’s affairs at the Reich Education Ministry, distrusted Stark, who had aligned himself with Rust’s political opponents in Nazi circles.) Well then, said Stark, it must be Lenard. Rust approved of that idea, but now Lenard himself declined, saying he was too old. No other successor was put forward, and meanwhile Planck stayed on.

It was a delicate moment, since the Aryan physicists weren’t alone in regarding the KWG as ideologically suspect. After the society’s twenty-fifth anniversary celebrations in January 1936, the Nazi news­paper Völkischer Beobachter called it a “playground for Catholics, Social­ists and Jews”, while the SS journal Das Schwarze Korps had portrayed it as a “restricted circle” basking in elitist “aristocratic splendour”. Planck knew that Rust would not endorse a replacement who was too closely associated with Einstein, and would prefer someone known to be faithful to the party. The minister would also insist that the organiza­tion now adopt the Führer principle. But the KWG senate cannily identified a candidate who, as an industrialist, could retain some inde­pendence from political influence, while as a staunch patriot should be unobjectionable to the leaders: the chemistry Nobel laureate Carl Bosch. He was duly elected in 1937. But in place of the secretary Friedrich Glum, Rust appointed the Nazi official Ernst Telschow, who had some chemical training and had worked briefly under Otto Hahn. As Bosch was frequently plagued by illness, Telschow took over much of the society’s practical business. Arguably this was no bad thing for the KWG, for Telschow was a canny administrator, able to form links with the Nazi regime that would benefit the society. One of those individuals who knew how to adapt to the prevailing political climate, Telschow was active in the (renamed) society after the war and was finally elected a senator in 1967.

While the KWG was not exactly Nazified in 1937, then, neither did it thenceforth mount any effective resistance to the wishes of the government. It expelled the remaining Jewish members, including Lise Meitner, even though she continued to work at Hahn’s institute in Berlin.

White Jews

This outcome did not afford the Deutsche Physiker much satisfaction, and in 1937 Stark decided it was time to find another line of assault on his enemies in theoretical physics. Planck’s influence was evidently waning, and now Stark found a new target: a young professor who was enjoying the fame that Stark so coveted and who had made quantum theory an even more impenetrable thicket of mathematical formalism, who supported Einstein’s ideas, had been awarded a Nobel Prize at the absurdly premature age of thirty-one, and now looked about to be appointed as Sommerfeld’s successor in Munich. Stark began a crusade against Werner Heisenberg.

Heisenberg had been in Stark’s sights ever since he had refused to attend the rally of the National Socialist Teachers League in Leipzig in November 1933. On that occasion Stark hoped to agitate Heisenberg’s students into protest, but Heisenberg defused the situation by inviting the leader of the local Nazi Students League to his house and persuading him that he was a trustworthy, albeit “apolitical”, professor. Emboldened by this victory, at the gathering of the Society of German Scientists and Physicians in Hanover in September 1934 Heisenberg defended relativity and quantum theory against Stark’s accusations that they were speculative. There he even mentioned Einstein by name, earning him a reprimand from the Nazi chief ideologue Alfred Rosenberg.

But by 1935 Heisenberg was deeply disheartened by the political climate. His sense of patriotism and honor was disturbed after the Nuremberg Laws had removed the exemption from dismissal for Jewish veterans of the First World War. He had even risked damaging his reputation and prospects by registering that displeasure at a faculty meeting. His words of protest, however, show how the Nazis had already set the parameters of the debate: Heisenberg said he doubted “that the measures now being taken are consistent with the intention of the law, according to which front veterans also belong to the Volk community”. In other words, it was not the principle of an exclusive national community that he challenged, but who was selected for membership.

On that occasion Heisenberg had considered resigning (or so he claimed), but was dissuaded by Planck, who cautioned once again that this would be a futile dereliction of duty. “It is to the future that all of us must now look”, the older man advised: they must hang on regardless, for Germany’s sake. Like most of his peers, Heisenberg withdrew into physics. “The world out there is really ugly”, he wrote to his mother, “but the work is beautiful.”

The immediate trigger for Stark’s attack on Heisenberg in 1937 was a long-running dispute about the successor of Arnold Sommerfeld, who two years earlier had been due to retire from his professorship in Munich. It was no secret that Sommerfeld wanted Heisenberg to have the post, and it was said that the “list” of candidates submitted by the university to the Bavarian administration contained his name and no other.

Stark and Lenard hoped that Sommerfeld’s departure could be used to free the Munich faculty from his baleful support of “Jewish physics”. In an address at the new Philipp Lenard Institute for Physics in Heidelberg in December 1935, Stark called Heisenberg a ‘spirit of Einstein’s spirit’. This speech was printed in the January issue of the party periodical Nationalsozialistische Monatshefte. In February Heisenberg placed a response in the Völkischer Beobachter, although it was printed with a further comment from Stark. Concerned about the damage to his career and reputation, Heisenberg sought an audience with Rudolf Mentzel, Rust’s deputy at the REM, at which he argued that theo­retical physics was important and needed to be defended against the diatribes of the Deutsche Physiker. Probably because of internal party politics rather than scientific judgement, Mentzel looked favourably on the appeal, but advised Heisenberg to send a letter to all German university physics professors asking if they took the same view. Together with Max Wien, a physicist at Jena, and Hans Geiger – both carefully selected as experimentalists sympathetic to his cause – Heisen­berg drafted the letter, which demanded that the attacks of Stark and Lenard should cease for the sake of Germany’s international reputa­tion. Nearly all of the seventy-five professors who received the letter signed their approval.

Thus Stark had succeeded only in showing the REM that there was scarcely anyone else on his side. To make matters worse, he was forced to resign as head of the German Research Association in November 1936 after squandering its funds on a hare-brained idea to extract gold from the moors of southern Germany. But this apparent victory did little to improve Heisenberg’s mood. Despite marrying in early 1937, he found himself mired in despair and gloom in Leipzig, apparently close to a breakdown and admitting that, when he was not with his new bride, “I now easily fall into a very strange state.” In March he was finally offered Sommerfeld’s professorship, which he accepted but deferred until August. That turned out to be a mistake, because it gave Stark the chance to intervene again.

In July Stark published in Das Schwarze Korps a new, trenchant vili­fication of Heisenberg, along with others who colluded in the “Jewish conspiracy” in physics without being Jews themselves. These people, he said, were “White Jews”—a designation calculated to make them the legitimate targets of all the abuse previously heaped on the Jews themselves. Planck, Sommerfeld and their circle were denounced as “bacterial carriers” of the Jewish spirit who “must all be eliminated just as the Jews themselves”. And none more so than Heisenberg, “this puppet of the Einsteinian ‘spirit’ in new [Weimar] Germany”. Even today, Stark claimed, the core of Heisenberg’s students “still consists of Jews and foreigners”. The young pretender himself was the “Ossietzky of physics”, implying that he was no less dangerous to German culture than the dissident Carl von Ossietzky who the previous year had been awarded the Nobel Peace Prize– and that Heisenberg, like Ossietzky, should therefore be in a concentration camp. A disgusted Peter Debye showed the article to the senate of the KWG, reporting that “it was condemned by everyone with whom I spoke”.

Heisenberg was now in a bind. He had to extricate himself from the “White Jew” accusation without appearing to distance himself from Einstein’s “Jewish” physics. His response was telling: it was not enough simply to defend his good character, he also sought official sanction from the state leaders. Thus he directed his appeal to the Reichsführer of the SS, Heinrich Himmler, insisting that he must either have complete vindication at the highest level or he would resign and emigrate. He reminded the authorities that he had plenty of offers from abroad, in particular from Columbia University in New York. Having previously refused to “desert” Germany in the face of the Nazi excesses, he thus contemplated it, or at least threatened it, now to save his “honor”. As historian Paul Lawrence Rose argues, Heisenberg’s counter-attack on Stark should not be interpreted as a rejection of Nazism or anti-Semitism; it was driven by pride, anger, and fear for his reputation.

In cases like this, one needed to exploit personal connections for all they were worth. Heisenberg’s mother was acquainted with Himmler’s mother, and she argued her son’s good character in a way that Frau Himmler would appreciate: as mother to mother. Frau Himmler promised that she would get her Heinrich to “set the matter back in order”. “There are some slightly unpleasant people around Heinrich”, she admitted, “but this is of course quite disgusting. He is such a nice boy—always congratulates me on my birthday.”

Himmler, however, at first remained neutral. He simply requested a detailed response from Heisenberg to the accusations made by Stark, while at the same time ordering an investigation into Heisenberg’s character. The Gestapo and SS bugged Heisenberg’s house, placed spies in his classes, and questioned him on several occasions. This exhausting and frightening process finally resulted in a report that exonerated Heisenberg, portraying him as an “apolitical” scientist who was basically a good patriot with a positive attitude towards National Socialism. It explained that Heisenberg had initially been trained in “Jewish physics”, but claimed that his work had become increasingly “Aryan”. True, he did not show the antipathy towards Jews that one might hope for, but perhaps he would develop the proper attitude in due course.

Himmler received the report in the spring of 1938, but to Heisen­berg’s immense frustration he did not act at once. Finally in July he was prevailed upon to write to Heisenberg, saying “I do not approve of the attack of Das Schwarze Korps in its article, and I have proscribed any further attack against you.” He invited Heisenberg to discuss the matter with him “man to man” in Berlin later in the year. The invita­tion was, despite Heisenberg’s eagerness, never fulfilled, but the two men remained in cordial contact through the war. Given the other demands on Himmler’s time, the attention he gave to this matter is in fact rather remarkable. Mark Walker attests that Himmler was very interested in science and considered himself something of a patron of scientists. A personal letter and invitation from Himmler was more than most of them might have expected.

It was nonetheless a ruthless kind of patronage. When Himmler explained his decision on Heisenberg to the head of the Gestapo Reinhard Heydrich, he wrote with icy pragmatism that “I believe that Heisenberg is decent; and we cannot afford to lose this man or have him killed, since he is a relatively young man and can bring up the next generation.” Moreover, Himmler concluded with a bathetic indi­cation of his scientific ignorance, “we may be able to get this man, who is a good scientist, to cooperate with our people on the cosmic-ice theory”. To Heisenberg’s good fortune, it seems he was never asked to give an opinion on the matter.

Himmler also added chilling words of advice in his letter of exon­eration to Heisenberg, saying “I would consider it proper, however, if in the future you make a clear distinction for your listeners between the recognition of the results of scholarly research and the personal and political attitude of the researcher.” In other words, Heisenberg would do well not to mention Einstein. He got the point, and obeyed.6 He had already indicated that intention in a letter sent in March to Ludwig Prandtl, an expert in aerodynamics at Göttingen, who had tipped off Heisenberg that exoneration from Himmler was on its way:

“I never was sympathetic toward Einstein’s public conduct . . . I will gladly follow Himmler’s advice and, when I speak about the theory of relativity, simultaneously emphasize that I do not share Einstein’s pol­itics and world view.”

Having been granted his wish to “set the record straight” with the guarantee of an article in Zeitschrift für die gesamte Naturwissenschaft, the house journal of the Deutsche Physik movement, he pursued this concession doggedly over the next few years, again asking Himmler to intercede when difficulties arose. That his article, “Evaluation of the “modern theoretical physics”, was not actually published until 1943 rather defeated its original object. He consented therein to the usual compromise of acknowledging Einstein’s discoveries while suggesting that they would have happened anyway: “America would have been discovered if Columbus had never lived, and so too the theory of electrical phenomena without Maxwell and of electrical waves without Maxwell, for the things themselves could not have been changed by the discoverers. So too undoubtedly relativity theory would have emerged without Einstein.”

These accommodations and entreaties to the Nazis may seem hard to understand today. Could Heisenberg really have imagined, after an episode like Stark’s attack, that things were going to get any better? That, if he could only “clear his name”, somehow the relationship of physics with the National Socialist state could be set back on track? But it was not naïve optimism that kept him bound to the Fatherland, but rather, “an unbreakable attachment to Germany [that] his entire life and upbringing had instilled in him”, as his biographer David Cassidy puts it. To Heisenberg, Cassidy says, “remaining in Germany was apparently worth almost any price, as long as he could continue to work and teach”. What is more, Heisenberg had developed a convic­tion that his own fate was tied to that of the whole of German physics; if he left, nothing would remain. But as Cassidy points out, “by seeing himself in such a grandiose rationalization for remaining in Germany, he more easily succumbed to further compromises and ingratiation with the regime”.

In fact things really did improve eventually for Heisenberg, if not necessarily for German physics: by 1944 he was celebrated in Goeb­bels’ weekly propaganda newspaper Das Reich as a “German national leader”. This only lends weight to Rose’s accusation that “Heisenberg’s notion of “responsibility” as the acquisition of influence in Nazi circles was actually a rationalization of collaboration and of self-interest.”

What of the Munich post that had prompted Stark’s assault? In that regard Stark was indirectly successful, preventing Heisenberg ever from becoming Sommerfeld’s heir. The position fell foul of political wrangling between the REM, the SS, the Munich faculty and the Nazified University Teachers League, out of which Sommerfeld’s replacement emerged on the eve of war in 1939, in the form of an undistinguished mechanical engineer named Wilhelm Müller, who opposed the “new” physics and would teach only the classical variety. When Walther Gerlach, an expert in quantum theory at Munich, complained to the dean of the university that no theoretical physics was now being taught there, he was curtly told that “If you only understand theoretical physics to mean the so-called modern dogmatic theoretical physics of the Einstein–Sommerfeld stamp, then I must inform you that this will indeed no longer be taught at Munich.”

The wrong battle?

The battle fought within German physics in the 1930s was not that of apolitical scientists against the National Socialists, but of Einstein’s supporters against Deutsche Physik. One might have expected the National Socialists to embrace a view of physics that discredited Jews, but they were not quite as foolish as that. Physics under the Nazis was never really hijacked by ideology, for the political leaders were primarily interested in practical outcomes and not academic disputes. An internal REM memo to Bernhard Rust on the controversy over “Jewish physics”, probably sent by the ministry’s undersecretary (who here seems concerned that the blundering Rust might make a fool of himself ), advised that “In the case of a purely scientific dispute, in my opinion, the minister should keep himself out of it.” Until nuclear fission was discovered in 1938, the new theoretical physics was of little interest to the authorities, as it seemed to be largely irrelevant to the war preparations. And once atomic power looked possible, it was clear that the Aryan physicists’ advocacy of practical experiment over abstract theory could not deliver results. Rather, it was evidently the proponents of “Jewish” quantum theory and rela­tivity who truly understood the secrets of the atomic nucleus, and even the Nazis could see that they were the only ones likely to put the discoveries to good use.

Deutsche Physik also floundered through the political ineptitude of Stark and Lenard. Stark in particular was apt more to antagonize than to persuade the party officials. “Had he been less crazy”, science histo­rian John Heilbron comments laconically, “he would have been much more dangerous.” The Aryan physicists made wild blunders, but more incapacitating was their failure to appreciate that to get your way in Nazi Germany you needed to do more than regurgitate approved doctrines, prejudices and formulas. You needed to be able to manipulate the competing power blocs, to exploit the right contacts and forge useful alliances. Stark often backed the wrong horse—he had no more judgment in politics than he did in science.

As a result, the attempt of Deutsche Physik to take over the academic system failed. But its opponents had to tread a fine line, so that their defence of Einstein’s theories did not risk endorsing his unpopular political views. So long as they agreed to avoid too explicit an acknowledgement of the architect of the theory of relativity, they could generally get their way. During the war Heisen­berg regularly omitted Einstein’s name from the public lectures that he was asked to deliver to spread German culture in occupied territories. Indeed, historians Monika Renneberg and Mark Walker suggest that Deutsche Physik collapsed partly because it was rendered otiose by the compromises made by the mainstream physics commu­nity, which demonstrated, to the leaders’ eventual satisfaction, “their willingness and ability to help further the goals of National Socialism”.

The struggle against Deutsche Physik, although frustrating for the German physicists who rejected it, offered a convenient narrative after the war by supplying a criterion for partitioning physicists into those who were Nazified and those who resisted them. In this view, if you had opposed Aryan physics, you had in effect opposed the Nazis—all the guilt of the National Socialist era could be transferred on to Lenard, Stark and their supporters. Better still, one could use this division to apportion scientific competence: the Aryan physicists were universally poor scientists, their opponents always proficient.

But the truth was that, while the dispute rumbled on through the late 1930s, the Nazis tightened their grip on German science regard­less. In some disciplines, such as chemistry, scientists fell into line in short order. In a few, such as anthropology and medicine, the collu­sion of some researchers had horrific consequences. Physics was another matter: just docile enough for its lapses, evasions and occa­sional defiance to be tolerated. The physicists were errant children: grumbling, arguing among themselves, slow to obey and somewhat lazy in their compliance, but in the final analysis obliging and dutiful enough. If they lacked ideological fervour, the Nazis were pragmatic enough to turn a blind eye. Their attitude is conveyed perfectly in a description of Ludwig Prandtl sent by the local Nazi coordinator (Kreisleiter) in Göttingen to his superiors in May 1937. As we saw, Prandtl had supported Heisenberg against Stark’s attacks, and he had appealed to Himmler about the damaging effects on German science of the Deutsche Physiker attacks. The Kreisleiter’s letter makes it clear how indifferent the Nazis were to such arguments, and how mean­ingless or even contemptible the notion of a “duty to science” was to them. All that mattered was whether the scientists were prepared to lend their efforts to mobilization of the Fatherland, which Prandtl did willingly:

“Prof. Prandtl is a typical scientist in an ivory tower. He is only interested in his scientific research which has made him world famous. Politically, he poses no threat whatsoever…Prandtl may be considered one of those honorable, conscientious scholars of a bygone era, conscious of his integrity and respectability, whom we certainly cannot afford to do without, nor should we wish to, in light of his immensely valuable contributions to the development of the air force.”

FOOTNOTES