An Analysis of Ninth-Century Reception of Claudius Ptolemy's Astronomy in the Arabic Tradition
[Thesis]
Americo, Maria
Jones, Alexander
New York University
2019
377 p.
Ph.D.
New York University
2019
My dissertation focuses on reception of and engagement with the work of the ancient Greek astronomer Claudius Ptolemy by astronomical authors writing in Arabic during the ninth century CE. Though smaller-scale, more specific considerations and analyses of the relationship between the work of Ptolemy and that of particular authors of Arabic astronomical texts have been undertaken, most of these have been in conjunction with a focused edition or study of one of these authors, or sometimes as part of a study of a particular school of thought or astronomical theory. Never has a full-scale study of the general picture of reception of Ptolemy's astronomical texts and ideas in the ninth-century Arabic tradition been offered, giving a coherent, holistic sense of the intellectual atmosphere of astronomy across a number of texts and authors. I will give this picture of ninth-century Ptolemaic astronomy in Arabic through an analysis of nine ninth-century texts. The nine texts I will be working with are: al-Kindī's Book of the Great Art; al-Hāshimī's Book of the Reasons Behind Astronomical Tables; Ḥabash al-Ḥāsib's text on the sizes and distances of the celestial bodies; al-Farghānī's Introduction to Astronomy; the Banū Mūsā's text on whether a ninth sphere is needed in the universe; Thābit ibn Qurra's oeuvre; and a previously unpublished text, found in the Bodleian Library's MS Arch. Seld. A. 11, often attributed to the physician and translator Qusṭā ibn Lūqā (c. 820-912 CE), which is another example of an early Arabic astronomical text with strong ties to the Ptolemaic tradition. The inclusion of some excerpts of this well-known but never before published text will greatly enrich the study of the intellectual history of the Islamic ninth century. This text is unique in a number of ways, not the least being its knowledge of and reference to Ptolemaic texts and numerical parameters not often found in Arabic literature. When discussing this text, I will provide my own edition and translation of selected excerpts of it. After providing some historical background on some topics such as the larger project during the period of the 'Abbasid caliphate of translating texts out of ancient languages into Arabic as well as the social and intellectual implications of this, the context of astronomical research in the Islamic world in the ninth century, the tradition of ancient and Late Antique astronomical and cosmographical texts, and the lives and works of the authors I will discuss, I proceed to compare and analyze the texts. I undertake this analysis in two different ways: (1) by comparison of the authors' different methods of handling certain research questions in astronomy and their values given for certain mathematical parameters (for example, the periods of the planet Saturn or the length of the year); and (2) their engagement with the astronomical texts of Ptolemy, who was a major source for all six authors. I ask how each text treats the material found in its source: do the authors critique Ptolemy's astronomical theories, observations, and research findings? Do they offer new or better ones? Do they simply take them as fact? Do they regard Ptolemy and the ancient Greek astronomical tradition with respect, criticism, or a combination of the two? Through consideration of these questions, I will attempt to draw some conclusions about ninth-century Arabic astronomy and its relationship to ancient Greek astronomy, and some larger conclusions about the nature of scientific tradition and development throughout history.