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. (shrink)

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

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 Al al-D who, in his youth, had been instructed in the mathematical sciences by none other than the famous Central Asian monarch Ulugh Beg (1394 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 Qushji's reform of (...) the Ptolemaic model for Mercury includes a critical first edition of Qushji's Arabic text, an English translation, and a historical and technical commentary. (shrink)

Commentaire d'un fragment de texte astronomique grec de Paul d'Alexandrie et de ses autres versions, plus tardives, en syriaque et en arabe, qui permettent d'étudier la transmission des textes et d'une langue à une autre.

This paper argues that the views of Charles Taylor on justice in income and wealth distribution are fallacious, especially in regard to issues such as private property rights, justice, human rights, and theft. As to this last point, Taylor maintains it is possible, under certain circumstances, to “legitimately steal.” We regard this as a philosophical howler of the first order. We also demur from his contention that equity and equality can be used as synonyms.

Name der Zeitschrift: Der Islam Jahrgang: 94 Heft: 2 Seiten: 423-433.

Este artículo presenta el descubrimiento de un texto hasta ahora desconocido, llamado al-lstidrāk, obra de un astrónomo anónimo andalusí del siglo XI que conoció personalmente a Azarquiel y que planteó sus dudas acerca de la tradición astronómica griega. Sobre la base de este nuevo texto, el artículo pone en cuestión la idea que se ha venido manteniendo de que la tradición astronómica islámica fue sobre todo filosófica en al-Andalus y más matemática en Oriente. Se aducen además datos de ambos lados (...) del Mediterráneo que demuestran que hubo una continuidad y unos contactos entre los dos extremos. El artículo mantiene que la falacia en esta caracterización de la astronomía islámica proviene de una falsa comparación entre las obras de filósofos occidentales con la de astrónomos orientales; cuando se comparan las obras astronómicas del Este y del Oeste queda claro que fueron los mismos problemas los que se plantearon en obras astronómicas en todo el orbe islámico. También se hace evidente que astrónomos orientales como Ibn al-Shāṭir de Damasco estaban sensibilizados a las mismas cuestiones filosóficas que preocupaban a los filósofos andalusíes y respondieron a estas cuestiones con sus propias respuestas filosóficas. (shrink)

BĪRŪNĪ, ABŪ RAYḤĀN MOḤAMMAD b. Aḥmad (362/973- after 442/1050), scholar and polymath of the period of the late Samanids and early Ghaznavids and one of the two greatest intellectual figures of his time in the eastern lands of the Muslim world, the other being Ebn Sīnā.