The essence of the theory of minima naturalia is the contention that a physical body is not infinitely divisible qua that specific body. A drop of water cannot be divided again and again and still maintain its “wateriness”. There are several statements in Aristotle's Physics which suggest such an interpretation, and the theory of minima naturalia is commonly considered to have originated in the thirteenth century as an interpretation of these statements. The present paper is a preliminary presentation of the role of Ibn Rushd in the evolution of the theory, hitherto neglected. His theory developed not only as an elaboration on the “suitable” statements of Aristotle, but mainly as an attempt to solve the difficulties raised by Aristotle's thesis (developed in Physics VI and VII) that body and motion are continuous, infinitely divisible entities and are associated qua such. According to Ibn Rushd's interpretation, body and motion are associated not qua being continuous but qua having indivisible minimal parts. It seems that Epicurus' and Ibn Rushd's theories of minima developed as responses to Physics VI and offer modifications of classical atomism and of classical Aristotelianism (respectively), which to a certain extent reduce the gap between these two systems.

That the medieval Latin version of Ibn al-Haytham's Kitāb al-Manā[zdotu]ir was translated into Italian in the fourteenth century has been known for well over a century. Recent studies have shown that this translation, which is contained in Vat. Lat. 4595, was instrumental in the composition of Lorenzo Ghiberti's Commentario terzo on art. Some eight years ago, the author of the present article tentatively identified the actual manuscript-source of that translation as MS Royal 12.G.7, which is currently held in the British Library. This study establishes beyond reasonable doubt that his tentative identification was correct: MS Royal 12.G.7 is indeed the Latin source for the Italian translation in Vat. Lat. 4595.

The only traces which remain of Abū Sahl al-Qūhī's work on centers of gravity are the correspondence he maintained with Abū Is[hdotu]āq al-[Sdotu]ābi', and the first chapter of the Kitāb Mīzān al-[hdotu]ikma, which 'Abd al-Ra[hdotu]mān al-Khāzinī attributes to al-Qūhī and to Ibn al-Haytham, without distinguishing between their respective contributions. The author of the present article attempts to confront the texts and to analyse all the testimonies which have come down to us on this subject, which are susceptible of shedding light upon al-Qūhī's contribution and the importance of his work on centers of gravity.

The aim of this paper is to present the modes of action of venom as construed by Abū 'Uthmān 'Amr ibn Ba[hdotu]r al-Jā[hdotu]i[zdotu] (780-868) in his Kitāb al-[Hdotu]ayawān (The Book of Animals). The toxicological information presented by Jā[hdotu]i[zdotu] is a synthesis of data available in his time, but Jā[hdotu]i[zdotu] complemented these early conceptions by his personal theoretical views. Jā[hdotu]i[zdotu]'s fundamental idea is that venoms act through their specific natures; this idea in a way is reminiscent of present-day theory of enzymes.

Abraham ibn Ezra's (ca 1089-ca 1167) scientific corpus represented an exceptional case: instead of the common Latin model embodied by the scholar coming from the Christian North to the Iberian Peninsula to initiate a translation enterprise, we have in Ibn Ezra the contrary case of an intellectual imbued with the Arabic culture, who abandons al-Andalus, roams around the Christian countries and delivers in his wandering through Italy, France and England, the scientific and cultural cargo that he amassed during his youth in al-Andalus. The main purpose of this article is to provide a picture of Ibn Ezra's scientific corpus as comprehensive and detailed as possible given the present state of research. The paper will fall into two main parts: (a) Ibn Ezra's scientific work will be broken up into three main genres: (1) Mathematics, Astronomy, Scientific Instruments and Tools; (2) The astrological encyclopaedia; (3) Translations from Arabic into Hebrew. (b) In the second part, Ibn Ezra's scientific corpus will be reassembled as a whole in order to provide a global characterization, trying to point out its general organization and shape, and to indicate its main aims and special traits revealing Ibn Ezra personal contribution.