l x x x i i I N T R O D U C T I O N T O V O L U M E 1 6 people still wanted to hear about Einstein’s theory of relativity. In this volume we see that he had developed rhetorical schemes for introducing the complex ideas that underpinned the theory, as for instance in Doc. 44. This short essay on relativity appeared in a book published by the popular bookseller Reclam in late 1927, whose editions reached a vast audience in the German-speaking world. His approach in this paper was to focus on the big picture, portraying his work in unification terms, the special theory having unified mechanics with electrodynamics and the general theory as unifying geometry with gravitational physics. In this way unification was presented to the public as an underlying program in physics, placing Einstein’s lat- est work as a natural final step in a historical process. The great public interest in Einstein’s efforts to develop a unified field theory of gravity and electromagnetism demanded that he also grapple with the new theory of quantum mechanics in his popular expositions. Einstein was obliged to write a popular account of his new unified field theory (Doc. 387) which appeared in sev- eral venues, including the New York Times and the English magazine The Observa- tory, aimed at both professional and amateur astronomers. This is also apparent in his talk at the first Davos conference (Doc. 156) and the text, translated from that talk, which was reprinted in an American newspaper (Doc. 329). It may be that Einstein had reservations about how successful he was in getting the big concepts of theoretical physics across, especially to the readers of a major newspaper, but he had no aversion to trying, even if he was not overly optimistic about the outcome. But it is obvious that the appeal here was the chance to address the students of the Davos courses. The famous sanatorium of this Swiss resort attracted many well- educated patients for whom the management put on university-level courses and lectures given by the finest minds in Europe. What finer mind to open the first con- ference in 1928 than Einstein’s? In addition, the school sought not only to benefit tubercular patients but to provide a venue in neutral Switzerland at which scientists from France and Germany could mingle for the first time since the Great War (Grandjean 2011). Einstein, with his pacifist credentials, fitted the bill perfectly and spoke at the opening ceremony in addition to giving the inaugural lecture (Docs. 156, 157). The Davos University Lectures could be regarded as an educational rather than a popularization enterprise, and Einstein was committed to such goals throughout his life (see Gutfreund and Renn 2015 for other examples). But even so, Einstein’s lecture there was hardly technical in nature, since many well-educated people, like the students at Davos, lacked a technical background. It is revealing that his lecture