George Saliba

The Astronomical Tradition Of Maragha: A Historical Survey And Prospects for Future Research

This paper surveys the results established so far by the on-going research on the planetary theories in Arabic astronomy. The most important results of the Maragha astronomers are gathered here for the first time, and new areas for future research are delineated. The conclusions reached demonstrate that the Arabic astronomical works mentioned here not only elaborate the connection between Arabic astronomy and Copernicus, but also that such activities, namely the continuous reformulation of Greek astronomy, were not limited to a specific group of astronomers or to a specific geographical area. It is shown that such activities were spread over a period of more than seven hundred years, from the early eleventh till the sixteenth century, and over an area stretching from the Andalusian peninsula in the west to the farthest reaches of Central Asia in the east.

Theory and Observation in Islamic Astronomy: The Work of IBN AL-SHĀTIR of Damascus

I am aware of only one study that is especially devoted to the relationship between theory and astronomical observations in medieval times, namely an article of Bernard Goldstein, which discusses mainly the works of Levi Ben Gerson (1288-1344).1 Of the other medieval astronomers, especially those writing in Arabic, only a few have been studied; and that was done specifically in terms of their reaction to Ptolemaic astronomy. Furthermore, the study of the works of these astronomers has centred around the models for planetary motions that these astronomers proposed as alternatives to the Ptolemaic models, and has not, as far as I know, been concerned with the relationship between the models and the observations on which those models may have been based. The following paper attempts to fill this gap by concentrating on the works of the Damascene astronomer Ibn al-Shatir (d. 1375).

The Spherical Case of the Tūsī Couple

In this article we study the development of the mathematical theorem, now known as the Tūsī Couple, and discuss the difference between its plane and spherical applications.

Arabic versus Greek Astronomy: A Debate over the Foundations of Science

This short note is occasioned by the publication of a review essay by A. I. Sabra in this journal, under the title “Conaguring the Universe: Aporetic, Problem Solving, and Kinematic Modeling as Themes of Arabic Astronomy.” Sabra’s review itself was in turn occasioned by the recent publication of four books (all in the 1990s), two of which were written as dissertations by Sabra’s own students and under his own supervision, and the last two were written by the present author. As a review essay, Sabra’s assessment of the books under consideration is rather fair, and as far as his assessment of the present writer’s books is decidedly oattering, and, for all practical purposes, engaging enough to invite the reader to examine those books. Had Sabra’s essay review been only a review, however, it would not have been necessary to bring it once more to the attention of the readers of Perspectives on Science, except maybe to make a corrective statement or two whenever the essay strayed into error. But it proclaims to do more than that. In 52 densely printed pages, it attempts to determine the purpose and character of a whole tradition of astronomical writings that occupied a major place in Islamic civilization for slightly more than a millennium, from the ninth to the twentieth century, a Herculean task in itself. The tradition in question was the one commonly known as the hay’a tradition, whose very name is still problematic since no one has ever been able to demonstrate that the term hay’a had any Greek antecedents. Its beginnings though can be incontestably dated back to the middle of the ninth century if not before, as is evident from the work Kitab al-hay’a (Book on Astronomy) by Qusta. b. Luqa (o. 860), who was not mentioned in Sabra’s essay. Its purpose, as I shall argue below, seems to have been an attempt to set new foundations for the science of astronomy, thus giving

Artisans and Mathematicians in Medieval Islam

This review article explores the relationship between the artisans and mathematicians of medieval Islam by examining the earliest historical sources in which such a relationship is depicted, and by focusing especially on the technical language that was used to describe the actual functions of one type of artisan, namely, the architect or master builder. It also argues for the need to draw necessary distinctions between the various types of artisans in order to delineate the exact dimensions of their relationship with theoretical mathematicians. As an example, it demonstrates how a group of early texts could be used to prove the close relationship that had developed between artisans, who were instrument makers, and theoretical mathematicians.

Al-Qushjī's Reform of the Ptolemaic Model for Mercury

In this article the author analyzes a fifteenth-century Arabic reform of the Ptolemaic model for Mercury. The author of the reform was the Central Asian – Ottoman astronomer ‘Alā” al-Dīn al-Qushjī (d. 1474 A.D.) who, in his youth, had been instructed in the mathematical sciences by none other than the famous Central Asian monarch Ulugh Beg (1394–1449). Although the astronomers of Ulugh Begs circle are known to have produced extensive astronomical Persian tables, no one other than Qushjī has been yet identified to have produced a theoretical text devoted to the criticism, let alone the reform, of the Ptolemaic mathematical planetary models. The present article on Qushjis reform of the Ptolemaic model for Mercury includes a critical first edition of Qushjis Arabic text, an English translation, and a historical and technical commentary.

The Arabic Book

This long-awaited translation of Johannes Pedersens Danish work Den Arabiske Bog (1946) describes in vivid detail the production of books in medieval Islam, and outlines the role of literature and scholarship in Islamic society.Originally published in 1984.The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

Cultural Implications of Natural Disasters: Historical Reports of the Volcano Eruption of July, 1256 CE

This paper surveys historical reports related to a volcanic eruption that took place in the year 654 AH/1256 CE, in the vicinity of the city of Medina in Arabia. The paper deconstructs those reports in order to reveal the social, political, and religious reactions that were generated by that disastrous eruption. Fully driven by textual considerations of reports written after the fact—although some lived contemporaneously—this article tries to sort myth from fact, the rhetorical from the literal, the religious from the political, and finally the theoretical juridical from the devotional and practical, when the first was deemed counterfactual. It concludes by highlighting the manner in which religious rituals—like communal prayers, congregating at a holy place, and reminding political authorities of their religious duties—could be manipulated during times of disasters to produce political change and improve the social conditions of the community afflicted by such disasters. This article also examines the extent to which such disasters were used as vivid images of the Day of Judgment, thereby urging individuals to higher compliance with religious observance.

A New Alchemical Poem Attributed to Khālid b. Yazīd (d. ca. 705)

This paper deals primarily with the identification of an inaccurately catalogued alchemical poem attributed to the famous Umayyad prince Khālid b. Yazīd (d. 705), edited, translated, and commented upon here for the first time. The paper also addresses the authenticity of Khālid’s interest in alchemy and connects that interest to the need of the early Islamic empire to develop its own gold coinage as a sign of political independence from Byzantine coinage that was up till then the currency of the lands occupied by early Muslims in the regions of modern-day Egypt and Syria. On the matter of the legendry character of Khālid which was apparently started by Ibn Khaldun and passed on after him to most nineteenth-century and early twentieth-century orientalists, the paper exposes here the inner contradictions in Ibn Khaldun’s theorising on the matter, and his failure to understand why someone like the historical Prince Khālid would be interested in alchemy.

Islamic reception of Greek astronomy

Research in Islamic science over the last half century or so has clearly established that such old myths as Islamic science being a preservation of Greek science, or that science was always in conflict with religion in Islamic civilization as it was in Europe, or that the European scientific Renaissance was independent of outside influences –a European phenomenon par excellence– are now all subjects of great dispute if not altogether dead. In what follows I will illustrate the evidence that has put such myths into question with only few examples, since time and space do not allow me to elaborate more.