“Although up to now the [visual] image has been [understood as] a construct of reason,” Kepler observes in the fifth chapter of his Ad Vitellionem Paralipomena (1604), “henceforth the [visible] representations of objects should be considered as paintings [picturae] that are actual[ly projected] on paper or some other screen.” While not intended as a historical generalization (“up to now” having surely been meant within the narrow context of the treatise itself), this claim nonetheless reflects historical reality. Virtually all visual theorists before Kepler did, in fact, conceive of optical images as subjective, not objective constructs – or, to put it in modern terms, as virtual rather than real entities. By current lights, of course, the distinction between virtual and real images is both obvious and common-place: whereas the latter can be physically projected upon a screen, the former cannot.

This study, limited to Kitāb Taḥṣīl al-sa'āda, examines two points: the first point concerns the place of political science in the hierarchy of the sciences and its dependence on Metaphysics. This dependence gives it a theoretical status and a proper subject, namely voluntary intelligibles which appear as objective entities and stable essences. The second point to be examined concerns these intelligibles, considered in their relationship to deliberation. From this viewpoint, they appear as formal invariants open to different formulations which correspond to different modes of existence. These formulations are also formal rules to the realisation of intelligibles, and though they are more or less general, they are not universal. They are objects for deliberative discovery and the model of deliberative operations seems similar to the model of ingeniosity present in Algebra and the arts of ingenious devices.

N. Oresme passe pour l'un des rares (sinon le seul) grand universitaire médiéval mathématicien. C'est ainsi que son grand traité De Configurationibus qualitatum et motuum est vu traditionnellement comme un traité de mathématiques et analysé comme tel. En fait, l'examen de ses Questiones super Physicam montre qu'Oresme est un philosophe de la nature original. Ses thèses sont souvent en opposition avec celles de Buridan et saméthode est différente: ses arguments empruntent fort peu à la logique et presque exclusivement à la philosophie naturelle.

The author investigates the different readings of Ibn ṬufayPs epistle, Ḥayy b. Yaqẓan. Following a suggestion by L. Gauthier, who simply asked that the epistle should be read as a whole, the author adds Ṣalāḥ ‘Abd al- ḥabūr's reworking of the tale as a children's story to L. Gauthier's list of partial readings. The author juxtaposes Ṣalāḥ ‘Abd al- ḥabūr's reading, which does justice only to what Asāl taught Ḥayy, to G. Hourani's reading, which succeeds in reflecting only what Ḥayy taught Asāl. This impasse in the readings of Ḥayy b. Yaqẓān reveals what is missing, namely an understanding of the tale which fundamentally conforms to several of Alfarabi's teachings, though not to L. Gauthier's interpretation.

Dans sa description de l'œuvre en langue vulgaire de Lorenzo Ghiberti, Giorgio Vasari, quoiqu'il en dénigre certains aspects, saisit bien, nous semble-t-il, les traits marquants des Commentaires de Lorenzo, en particulier ceux du troisième livre concernant l'optique: Scrisse Lorenzo un'opera in volgare nella quale trattò di molte cose, ma sì fattamente che poco costrutto se ne cava… [que l'on en tire très peu de connaissances utiles…] Né tacerò che egli mostra il libro essere stato fatto da altri [Je ne tairai pas qu'il montre que le livre a été fait par d'autres personnes]

The aim of this paper is to identify the position the ru'yat Allāh holds within the curriculum of sciences described by the Iḫwān al-Ṣafa'. Their concept of knowledge is first clarified. The Ihwan use the terminology of rational knowledge to describe items of faith too. But faith is only an introduction to a greater knowledge. Now: is the supreme knowledge to be considered as speculative and theoretical, or are the ḫawciṣṣ, the only ones entitled to the vision of God, eventually obliged to rely on a kind of divine “revelation” or “inspiration”? If the “vision of God” appears beyond any possible connotation of knowledge in “rational” terms, it is unclear, however, whether the Ihwan use the concepts of “revelation” and “inspiration” as a way of explaining in a theological terminology the utmost degree of human knowledge (perhaps according to the same analogical function waḥy and ilhām appear to have in Ibn Sīnā). Moreover, the qualities and moral dispositions attributed to the “Friends of God” remind us of Sufi doctrines. Consequently, the question of the relation between Sufism and imāmite theories could be re-opened: the Iḫwānian definition of the “science of the transcendent” shows that the gnoseological itinerary is not concluded even with the “vision of God.”

The Aristotelian theme of the identity of the intellect and of the intelligibleis of the utmost importance in Averroes' noetics. This latter, studied in the Latin translations that the Latin philosophers of the thirteenth century scrutinized, rigourously develop this theme so as to preserve the supraempirical and transcendant character of necessary truth that human thinking identifies, thereto sacrificing the individual uniqueness of the intellective operation in its final instance. A Latin Master of the thirteenth century, Thomas Aquinas, adopts Averroes' insight into the transcendence of the noetic, and confirms it, even as he defends the strictly personal character of human intellection.

In diesem Aufsatz möchte ich einen Überblick über unser heutiges Wissen bezüglich der Übersetzung der Elemente Euklids ins Lateinische geben. Cicero hat als Quästor in Sizilien (im Jahre 75 v. Chr.) das Grab des Archimedes aufgesucht und instandsetzen lassen, er nennt gelegentlich Euklid und Archimedes (De oratore III, 33, 132) und er zitiert in Academica I, Buch II, § 116, die Definitionen von Punkt und Linie. Vor dem 6.

Les correspondances littérales relevées dans I.R.M. et F.D.G. conduisent naturellement à se demander si elles sont le signe d'une parenté entre ces deux textes et, si c'est le cas, à s'interroger sur le degré d'originalité de la doctrine rhétorique du premier de ces traités.

Ibn al-Bannā' of Marrakesh (1256–1321) is the author of one of the four extant “editions” of the unfinished zīj of Ibn Isḥāq (fl. Tunis and Marrakesh ca. 1193–1222): it contains a selection of his tables accompanied by a collection of canons, easy to understand, which makes the zīj accessible for the computation of planetary longitudes. The present paper studies some modifications of the structure of the tables the purpose of which is to make calculations easier. The tables of the planetary and lunar equations of the centre are “displaced." The tables of the equation of the anomaly of Mars, Venus and Mercury, are standard, while, in the cases of Jupiter and Saturn, the equation of the anomaly is calculated in the same way as that for the Moon. Ibn al-Bannā' appears as a clever adapter, who displays a clear ingenuity allowing him to introduce formal modifications which give his work an appearance of novelty which does not correspond to reality.