Published online by Cambridge University Press: 26 September 2008
Between 1550 and 1650, the intellectual elite of Ashkenazic (German-andYiddish-speaking) Jews, including rabbis such as Yom Tov Lipmann Heller(1578–1654), showed a marked interest in astronomy, and to a lesserdegree in the natural sciences generally. This is one aspect of the assimilationof medieval Jewish rationalism by that group. Passages from Heller‘swritings show his familiarity with medieval and early modern Hebrew astronomicaltexts, and his belief that astronomy should be studied by all Jewish schoolboys.Heller‘s astronomical views were then influenced by the discoveriesand debates of his period. Between 1614 and the 1630‘s, Heller movedfrom an Aristotelian to a Tychonic view of the nature of the celestial bodies.Inspired, furthermore, by the notion of a natural order subject to change, andbasing himself on the exegesis of ancient rabbinic texts, Heller offered what wehave termed” midrashic natural histories”: namely, ahypothesis concerning the development of a certain type of animal, and anotherconcerning the dimming of the moon and its movement into a lower orbit.