xxxvi INTRODUCTION TO VOLUME 5 a continuation of their relationship will lead to no good, neither for them nor for others, Einstein breaks off his correspondence with Elsa soon after it has started.[13] Only after a year has elapsed does he take it up again. Mileva must have suffered from the spiritual exhaustion of their marriage as well, and it would not be surprising if she clung to the marriage more stubbornly after all the sacrifices she had made. Suffice it to say that Einstein's primary affection all his life was for physics, and that his attitude toward women was far less "progressive" than his science. Coupled with Einstein's ambitions as a scientist and his cavalier attitude toward women was a strong and active concern for his academic career. His interest in improving his position and furthering his career sometimes left others less than pleased. We see, for example, Einstein casually accepting a call to the German University of Prague in January 1911, only six months after having been voted a significant increase in salary at the University of Zurich, his first real academic post, and after assuring the authorities that he would remain in Switzerland.[14] When he received an offer from the Dutch to the University of Utrecht in the fall of 1911 he very cleverly used it to pres- sure the Swiss into making a competing bid of a position at the ETH, his alma mater. Although he accepted the Swiss offer, it seems that he seriously con- sidered the Utrecht offer at least for a while. Apparently no one's feelings were hurt in this case, but Einstein's wavering did leave some people disap- pointed or puzzled, in particular Lorentz-a result that genuinely embar- rassed Einstein.[15] A perhaps more familiar Einstein is revealed in the glowing language of the doyen of German physicists, Max Planck, which is incorporated into the commission report that nominates Einstein for his position in Prague in April 1910: "In its breadth and profundity the revolution in the physical world-view occasioned by [the principle of relativity] can only be compared with that brought about by the introduction of the Copernican world-system."[16] This view of Einstein is reinforced in the characterization by Walther Nernst, who after a visit to Einstein in 1910 refers to him as a "Boltzmann redivivus."[17] A proper appreciation of Einstein in the Swiss Years will have to take both the more familiar and the unexpected into account. V Unlike the calls to Zurich in 1909 and 1912, Einstein's most fateful appoint- ment-the one to Berlin in 1914-was a total surprise to him and was due solely to the active urging of others. Though he later claimed that his cousin