It was July of 1967 and the clean-shaven Yeshayahu Leibowitz of the Hebrew University wore a kippah. Yes, a kippah adorning the head of a biochemist, talmudist, philosopher, and medical doctor, a Riga-born Jew keeping the Sabbath, the dietary laws, etcetera, a Zionist by way of Berlin, Heidelberg, and German-speaking Switzerland. His lantern jaw was familiar in the small town Jerusalem was then, especially in the Rehavia neighborhood where the yekkes at the university—the German-speaking Jewish refugees—made their homes. Leibowitz was not a yekke himself but an Ostjude, from the East. Still, you couldn’t ignore the Berlin and Basel degrees, or his wife Greta, herself a PhD in mathematics, a yekkit from North Rhine-Westphalia. Not an unimpressive couple.