to her cousin’s, and it would become strikingly more so as they aged.39
Einstein was looking for new companionship, and he first flirted with Elsa’s sister. But by the end of his Easter visit, he had settled on Elsa as offering the comfort and nurturing that he now craved. The love he was seeking, it seems, was not wild romance but uncomplicated support and affection.
And Elsa, who revered her cousin, was eager to give it. When he returned to Prague, she wrote him right away—sending the letter to his office, not his home, and proposing a way they could correspond in secret. “How dear of you not to be too proud to communicate with me in such a way!” he responded. “I can’t even begin to tell you how fond I have become of you during these few days.” She asked him to destroy her letters, which he did. She, on the other hand, kept his responses for the rest of her life in a folder that she tied and later labeled “Especially beautiful letters from better days.”40
Einstein apologized for his flirtation with her sister Paula.“It is hard for me to understand how I could have taken a fancy to her,” he declared. “But it is in fact simple. She was young, a girl, and complaisant.”
A decade earlier, when he was writing his love letters to Mari that celebrated their own rarefied and bohemian approach to life, Einstein would likely have lumped relatives such as Elsa into the category of “bourgeois philistines.” But now, in letters that were almost as effusive as the ones he had written to Mari
, he professed his new passion for Elsa. “I have to have someone to love, otherwise life is miserable,” he wrote. “And this someone is you.”
She knew how to make him defensive: she teased him for being under Mari’s thumb and asserted that he was “henpecked.” As she may have hoped, Einstein responded by protesting that he would show her otherwise. “Do not think about me in such a way!” he said. “I categorically assure you that I consider myself a full-fledged male. Perhaps I will sometime have the opportunity to prove it to you.”
Spurred by this new affection and by the prospect of working in the world’s capital of theoretical physics, Einstein developed a desire to move to Berlin. “The chances of getting a call to Berlin are, unfortunately, slight,” he admitted to Elsa. But on his visit, he did what he could to increase his chances of someday getting a position there. In his notebook he listed appointments he had been able to get with important academic leaders, including the scientists Fritz Haber, Walther Nernst, and Emil Warburg.41
Einstein’s son Hans Albert later recalled that it was just after his eighth birthday, in the spring of 1912, when he noticed that his parents’ marriage was falling apart. But after returning to Prague from Berlin, Einstein seemed to develop qualms about his affair with his cousin. He tried, in two letters, to put an end to it. “There would only be confusion and misfortune if we were to give into our mutual attraction,” he wrote Elsa.
Later that month, he tried to be even more definitive. “It will not be good for the two of us, as well as for the others, if we form a closer attachment. So, I am writing to you today for the last time and am submitting again to the inevitable, and you must do the same. You know that it is not hardness of heart or lack of feeling that makes me talk like this, because you know that, like you, I bear my cross without hope.”42
Einstein and Mari shared one thing: a feeling that living among the middle-class German community in Prague had become wearisome. “These are not people with natural sentiments,” he told Besso. They displayed “a peculiar mixture of snobbery and servility, without any kind of goodwill toward their fellow men.” The water was un-drinkable, the air was full of soot, and an ostentatious luxury was juxtaposed with misery on the streets. But what offended Einstein most were the artificial class structures. “When I come to the institute,” he complained, “a servile man who smells of alcohol bows and says, ‘your most humble servant.’ ”43
Mari worried that the bad water, milk, and air were hurting the health of their younger son, Eduard. He had lost his appetite and was not sleeping well. It was also now clear that her husband cared more about his science than his family. “He is tirelessly working on his problems; one can say that he lives only for them,” she told her friend Helene Savi
. “I must confess with a bit of shame that we are unimportant to him and take second place.”44
So Einstein and his wife decided to return to the one place they thought could restore their relationship.
The Zurich Polytechnic, where Einstein and Mari had blissfully shared their books and their souls, had been upgraded in June 1911 to a full university, now named the Eidgenossische Technische Hochschule (ETH), or the Swiss Federal Institute of Technology, with the right to grant graduate degrees. At 32 and by now quite famous in the world of theoretical physics, Einstein should have been an easy and obvious choice for one of the new professorships available there.
That possibility had been discussed a year earlier. Before he left for Prague, Einstein had made a deal with officials in Zurich. “I promised in private that I would advise them before accepting another offer from somewhere else, so that the administration of the Polytechnic could also make me an offer if they find it fit to do so,” he told a Dutch professor who was trying to recruit him to Utrecht.45
By November 1911, Einstein had received such an offer from Zurich, or at least so he thought, and as a result he declined the offer to go to Utrecht. But the matter was not completely settled, because some of Zurich’s education officials objected. They argued that a professor in theoretical physics was a “luxury,” that there was not enough lab space to accommodate one, and that Einstein personally was not a good teacher.
Heinrich Zangger, a longtime friend who was a medical researcher in Zurich, intervened on Einstein’s behalf. “A proper theoretical physicist is a necessity these days,” he wrote in a letter to one of the top Swiss councilors. He also pointed out that in such a role Einstein “needs no laboratory.” As for Einstein’s teaching talents, Zangger provided a wonderfully nuanced and revealing description:
He is not a good teacher for mentally lazy gentlemen who merely want to fill a notebook and then learn it by heart for an exam; he is not a
smooth talker, but anyone wishing to learn honestly how to develop his ideas in physics in an honest way, from deep within, and how to examine all premises carefully and see the pitfalls and the problems in his reflections, will find Einstein a first-class teacher, because all of this is expressed in his lectures, which force the audience to think along.
46
Zangger wrote Einstein to express his outrage at the dithering in Zurich, and Einstein replied, “The dear Zurich folks can kiss my . . . [und die lieben Zuricher konnen mich auch . . . (ellipses are in original letter)].” He told Zangger not to push the matter further. “Leave the Polytechnic* to God’s inscrutable ways.”47
Einstein, however, decided not to drop the matter but instead to push the Polytechnic through a light ruse. Officials at the university in Utrecht were just about to offer their open post to someone else, Peter Debye, when Einstein asked them to hold off. “I am turning to you with a strange request,” he wrote. The Zurich Polytechnic had initially seemed very eager to recruit him, he said, and it had been proceeding with haste out of fear that he would go to Utrecht. “But if they were to learn in the near future that Debye is going to Utrecht, they would lose their
