Astronomy and the Jewish Community in Early Islam

Abstract

Islam in the early Abbasid period was generally tolerant of religious diversity, but something much more surprising happened as well. An intellectual domain was created in which Muslims and non-Muslims were able to participate equally without compromising their separate identities. The extent of this domain may be difficult to determine, but astronomy and astrology were certainly elements in it. The effective founder of the Abbasid dynasty, the second Abbasid caliph, al-Manṣur (reigned: 754-775), built the new city of Baghdad near the ruins of the ancient sites of Babylon and the Sasanian capital, Ctesiphon. The date for the founding of the city was decided in consulation with a group of astrologers working for the caliph, and among them was a Jew, known as Mââshââʾallââh (d. ca. 815). Another Jewish intellectual involved in the formative period of Islamic science was Sahl ibn Bishr al-Yahudi, one of the leading astrological scholars of the early ninth century whose works were studied throughout the Middle Ages. Within the Jewish community astronomy played a significant role in the calendrical disputes between Rabbanites and Karaites. Saadia Gaon was the leading Rabbanite thinker of the tenth century, and anti-Karaite polemic is generally conspicuous in his writings. For him philosophy and science in the Greco-Muslim tradition serve as support for the principles of Judaism, despite their almost total absence from earlier Rabbinic sources. In his commentary on The Book of Creation , Saadia introduced both astronomy and astrology in a context that could only be understood as favorable to their study. Later, in the eleventh and twelfth centuries, astronomy was cultivated extensively by Jews in Muslim Spain. There was also a dispute concerning the validity of astrology, and we will consider, in particular, the attitudes of Judah Halevi and Maimonides.