(1541–1613), chronicler, astronomer, mathematician, and teacher. David Gans was born into a well-to-do merchant family in Westphalia. As a youth he studied with Mosheh Isserles, the renowned head of the Kraków yeshiva. Gans moved to Prague in 1564, where he continued his studies with Sinai ben Betsal’el, the brother of Maharal of Prague, and was associated with the latter as well.
In Prague, where he remained until his death, Gans befriended distinguished contemporaries. Efrayim of Luntshits, a renowned preacher and rabbi, wrote an approbation for Gans’s work Magen David (1612), as did the prominent Prague rabbis Yitsḥak Katz and Yom Tov Lipmann Heller. In 1600, Gans met astronomers Tycho Brahe, Johannes Kepler, and Johannes Müller, as well as their colleagues and students, who worked in Prague and at the imperial observatory in the Benátky summer palace of Rudolf II. He accepted their invitation to witness their work and spent five days at the summer palace on three separate occasions, later describing his observations as “wondrous.”
Gans was unique among the Jews of his day in his single-minded commitment to the liberal arts, particularly natural philosophy. By his own report, his interest in these subjects was sparked while he was still a student in Kraków (where Isserles was known to hold astronomy in high esteem) and was strengthened by his chance discovery of a Hebrew translation of Euclid’s Elements in his father-in-law’s house in Northeim. Ultimately, the knowledge that Gans amassed was eclectic and, as was true for many autodidacts, highly uneven.
Only one of Gans’s full books was published in his lifetime: Tsemaḥ David, which appeared in Prague in 1592. Tsemaḥ David was a two-volume chronicle, one devoted to Jews and the other to “the Monarchies” or “Nations of the World.” It was inspired by August Spangenberg’s Sächsische Chronica, which was the book’s principle source. Tsemaḥ David was meant to be a reference book, and at the same time to provide light entertainment for the well-to-do but poorly schooled merchant class. In 1612, Gans published a short version of his views on astronomy (Magen David), apparently hoping to secure funds to publish the full manuscript. The final version was not published until 1743, more than a century after his death, and was renamed Neḥmad ve-na‘im.
Gans’s unpublished works included two mathematics and geometry texts called Migdal David and Prozdor; a book on calculating the Jewish calendar titled Sefer ha-‘ibur; and another about the moon and its phases called Ma’or ha-katon. He also composed a guide for using a quadrant, a book on world geography called Gevulot ha-arets, and a Hebrew mappa mundi, or world map. He outlined a treatise on geometrics, which was to be called Sefer ha-medidah. Gans also planned to write about the location of the 10 lost tribes and perhaps about the kingdom of Prester John, though there is no evidence that he actually worked on these projects.
Gans wrote for householders and yeshiva students. One of his motivations was apologetic: he hoped that by educating Jews in the liberal arts and sciences he might improve their image among Christian contemporaries. Explaining why he wrote Tsemaḥ David, for instance, Gans explained that “we seem [to gentiles] like beasts who do not know their left from their right. . . . But with this book, the respondent can answer and say a small bit about every epoch, and through this we will appeal to and impress them” (Breuer, ed., 1983, pp. 166–167). Gans also believed that Jewish and Christian intellectuals could converse about certain subjects in the liberal arts and sciences in an atmosphere of mutual respect.
Gans had little or no impact on his contemporaries. His chronicle and, in particular, his earlier version, Magen David, received scant attention. He failed to carve out a place for natural philosophy and other liberal arts within the school curriculum even in Prague; if anything, interest in these subjects waned toward the end of his career. His hope of promoting better relations between Jewish and Christian intellectuals went unrealized. This was due in part to the onset of the Thirty Years’ War and its resulting political, social, and cultural changes. Gans’s ideals also failed to resonate among his contemporaries, who, from the start of the seventeenth century until the Haskalah, or Jewish Enlightenment, were less and less interested in humanistic culture and the natural world.
George Alter, Two Renaissance Astronomers: David Gans, Joseph Delmedigo (Prague, 1958); Mordechai Breuer, “Modernism and Traditionalism of David Gans,” in Jewish Thought in the Sixteenth Century, ed. Bernard D. Cooperman, pp. 49–88 (Cambridge, Mass., 1983); Mordechai Breuer, ed., Tsemaḥ David le-Rabi David Ganz (Jerusalem, 1983); Noah Efron, “Irenism and Natural Philosophy in Rudolfine Prague: The Case of David Gans,” Science in Context 10.4 (1997): 627–649; André Neher, Jewish Thought and the Scientific Revolution of the Sixteenth Century: David Gans (1541–1613) and His Times (Oxford, 1986).