By Joshua Holo
The Occult Sciences in Byzantium, eds. Paul Magdalino and Maria Mavroudi (Geneva, 2006)
Introduction: It is a commonplace that our modern, tidy distinction between astronomy and astrology does not apply to the Middle Ages. The celestial sciences shared a great deal, not merely in the basic fact of stargazing but also in terms of methods and applications, and this broad overlap blurred the line between them. Even following the definition of Maimonides (1135–1204), who strongly opposed astrology and distinguished it sharply from astronomy, a certain structural similarity emerges. According to this definition, astronomy measures the movements of celestial bodies, observes their influence on the natural world (such as the tides), and calculates their cycles in relation to the passage of time. Meanwhile, judicial astrology (henceforth, simply “astrology”) relies on its cognate science, but additionally claims to interpret, and frequently to predict, the influence of those bodies on future events and moral determinations. On the one hand, given this complex overlap, an author’s body of work—or even a single work in itself—frequently defies characterization as either astrological or astronomical. On the other hand, as Maimonides’ position instantiates, certain medieval Jewish perspectives distinguished between the two forms of heavenly investigation, and treated them, accordingly, as two separate pursuits with differently defined religious and cosmic applications. To be sure, not all Jewish points of view disconnected the two sciences, but the mere fact that some did is sufficient to prove that a retrospective merging of astrology and astronomy poses the same historical and intellectual problems as does an anachronistic separation between them. In tracing the contours and problems of that distinction between the celestial sciences as it played out in certain Byzantine Jewish texts, a religious outlook takes shape as a possible explanation for the apparently paradoxical fact that the Jews were aware of the potentially occult characteristics of astrology, even as they overwhelmingly embraced its validity.
Two well known, Hebrew-language, Byzantine-Jewish literary sources of tenth- and eleventh-century Southern Italy engage intensely with the celestial sciences, and they provide one possible framework for addressing this apparent paradox, in the context of a well defined period and location. Hebrew culture in Byzantine Southern Italy flourished in this period, the culmination of a shift in linguistic orientation first manifest in the increased use of Hebrew on headstones in eighth-century Apulia. Some of the notable compositions of tenth- and eleventh-century Byzantine Southern Italy include the Sefer Yosippon, a Hebrew abridgement of Josephus’ histories; Shabbetai Donnolo’s (c. 913 to c. 982) Sefer hakhmoni, a commentary on the Sefer yeṣirah, which is a lateantique, mystical cosmogony based on the Hebrew alphabet; and the Chronicle of Ahimaaz, penned by Ahimaaz b. Paltiel in Capua in the year 1054, recounting his mythical and magical family story, which stretches back to ninth-century Oria—the hometown of Shabbetai Donnolo—and which is frequently cited in the context of Byzantine-Jewish history.