What is law? There are many answers to this innocent question. In teaching introductory courses to first year students, teachers have to come up with a definition of sorts. But these definitions are never the last word on the issue. Notwithstanding thousands of years of jurisprudential debates, there is still not one generally accepted definition of law. And it is not likely there ever will be, as long as these debates continue. If ever there was one person uniquely qualified to settle the issue once and for all, it was Hermann Kantorowicz (1877-1940). This German scholar of jurisprudence had spent his whole life studying the systems of law developed from ancient times and he was the founder of the Freirechtschule, a movement advocating judicial freedom in interpretation and adaptation of the law. In 1938 he embarked on an ambitious project. Kantorowicz would be the editor of the Oxford History of Legal Science, a work to be divided into three volumes. The first was to cover ancient and oriental legal science (the Greeks, the Romans, the Byzantines). The second volume would treat medieval legal science (going deeply into Roman, Canon, Jewish, Germanic, French and English law). The third volume on modern legal science would treat the development of general jurisprudence in the United States and Europe. As an introduction, Kantorowicz wrote an essay in 1939 on The Definition of Law but his death prevented the further publication of the encyclopedia. The essay appeared as a separate book in 1958 (Kantorowicz 1958).