My research on Tanaka Kōtarō has taken far more time and received far more assistance from other scholars than this slim volume would suggest. I first became aware of Tanaka’s Theory of World Law at a 1993 academic conference in Milwaukee where Jim Bartholomew introduced it to me. So, of the many people to whom I’ve become indebted in the subsequent years of my research on Tanaka, it is first and foremost Jim whom I must thank for sparking my interest in the topic. Soon after that, I received a two-volume set of Tanaka’s Zoku sekaihō no riron from Walter Skya with whom I have had many profitable discussions on Tanaka and modern Japanese jurisprudence since. I was privileged to spend much of summer 2014 in residence at Waseda University as a Global Leadership Program scholar where, under the sponsorship of Uemura Tatsuo and Wakabayashi Yasunobu of the Law Faculty, I was able to study Tanaka’s early writings on commercial law. After a series of articles, chapters and presentations on Tanaka for over two decades, it was a sabbatical from Georgetown University and appointment at the International Research Center for Japanese Studies (Nichibunken) in Kyoto during calendar year 2015 that gave me the opportunity to devote myself full-time to my long-held dream of writing a book on Tanaka.