Imagine the following scenario: A young scholar from Vilna, having wandered through several cities in Eastern Europe and Germany arrived in the city of the Hague at the close of the 1780s, enjoyed the material support of the richest family of Jewish merchants in the city, the Boaz family, and sought and gained the religious approval of the rabbi of the city, Judah Leib Mezerich. His name was Pinhas Elijah ben Meir Hurwitz (1765-1821) and he was about to complete the first draft of a manuscript of his soon-to-be published book, an encyclopedia of the sciences entitled Sefer ha-Brit (The Book of the Covenant).1 The young Hurwitz soon learned of the presence of an aging sage who lived in the city, a rigorous philosopher and émigré from Mainz, Naphtali Herz Ulman (1731-87). Ulman had completed a multi-volume philosophic opus of which only the first volume, Hokhmat ha-shorashim [The Science of Roots or First Principles], had been published in 1781.2 Hurwitz was hardly a philosopher in his own right; in fact he had been drawn to the study of the kabbalah. But he did share something in common with Ulman — an appreciation of the life of the mind and particularly a fascination for the natural world and the new sciences, and they were both Ashkenazic Jews with knowledge of the German language.3 It seemed natural that Hurwitz would seek out Ulman and converse with the major intellectual figure of Hague Jewry.