SPÄTH, JOHANN PETER (Moses Germanus; 1642/45–1701), German Christian Hebraist who converted to Judaism. Späth was born either in Augsburg or in Vienna between 1642 and 1645 to a Roman Catholic family. He became a teacher in a Protestant family and this contact made him question his own faith. Influenced by the Protestant theologian Philipp Jacob Spener (1635–1705), Späth converted to the Lutheran church and he became a follower of Spener. His religious doubts, however, did not weaken. On the contrary, he became disappointed because of the controversy among the Lutherans, and this made him decide in 1681 to return to the Roman Catholic Church. However, he continued to have doubts. Several years later Späth appeared to be living in Amsterdam, where he met people from various religious movements such as the Mennonites, the Collegiants, and the Socians. During that period, he converted once again to become a Quaker. Thus he came into contact with the Christian Hebraist and Kabbalah scholar Francis Mercury of Helmont (1614–1699). At that time, Späth moved to Sulzbach to help with a Latin translation and the publication of a large corpus of Kabbalistic texts.
The chronological records of the subsequent years are not very clear, but in 1696 we find Späth in Amsterdam once again, where he officially converted to Judaism. From then on he was known as Moses Germanus. A year later he was circumcised and was accepted into the Portuguese-Jewish community in Amsterdam. He had previously married a Jewish woman, and was appointed as a teacher. Späth died in Amsterdam on April 27, 1701.
His conversion to Judaism caused the customary scandal in those days. Many of his contemporary Christian scholars expressed their disapproval of the facts. The most complete record of his life and his conversion written at that time is to be found in the work of Johann Jacob Schudt (1664–1722) entitled Jüdische Merckwürdigkeiten (= Jewish curiosities) in which he also talks about the dismay of the Christian scholars. Späth defended his conversion in a number of letters addressed to scholars in his area.
A great deal of that correspondence has been preserved, such as several letters to Johannes Leusden (1624–1699) dating from the period in which Späth converted, addressed by Leusden to Moses Germanus Judäus.
J.J. Schudt, Jüdische Merckwürdigkeiten, vorstellende was sich Curieuses und Denckwürdiges in den neuern Zeiten bey einigen Jahrhunderten mit Denen in alle IV Theilen der Welt, sonderlich durch Teutschland zerstreuten Jüden zugetragen, sammt einer vollständigen Franckfurter Juden-Chronik, darinnen der zu Franckfurt am Mayn wohnenden Jüden von einigen Jahrhunderten, biss auff unseren Zeiten, 4 vols. (1714–1718); H.J. Schoeps, Philosemitismus im Barock. Religions- und Geistesgeschichtliche Untersuchungen (1952), 81–87; idem, Barocke Juden – Christen – Judenchristen (1965), 83–92; A.P. Coudert and J.S. Shoulson, Hebraica Veritas? Christian Hebraists and the Study of Judaism in Early Modern Europe (2004); A.P. Coudert, in: M. Mulshow and R.H. Popkin (eds.), Secret Conversions to Judaism in Early Modern Europe (2004).