Before meeting in person, scholars often meet in print. And so it was that, more than three decades ago, I met Detlev Vagts, Harvard's Bemis Professor of International Law, in the pages of Transnational Legal Problems, a book we later came to co-author. I had seen him from a distance long before, when I was a Harvard law student. Although I never took his class, I often saw him sitting in his office deep in the stacks of the Langdell Library, usually with his door open, absorbed in a book he had pulled from the shelves. Someone told me that he was the son of a German scholar who had fled Nazi Germany. I heard from another that he was a man of great moral fiber, who would occasionally preach at Harvard's Memorial Church or speak with passion at contentious faculty meetings.

But I did not come to know Vagts' mind until I had graduated from law school, and started teaching International Business Transactions at night as an instructor at George Washington University Law School. As a young international lawyer in Washington in the 1980s, one day I found myself spending my whole day with Vagts the scholar: conducting research during the day as a Justice Department lawyer leafing through the American Journal of International Law (AJIL), for which he wrote and later served as Co-Editor-in-Chief; ducking out of work at lunchtime to attend a public session of the American Law Institute regarding the Restatement (Third) of the Foreign Relations Law of the United States, of which Vagts was Associate Reporter; then teaching at night from the 2nd edition of Transnational Legal Problems by Steiner and Vagts.