The most intensive and well-recorded intellectual encounter between Greek and Arabic is the 9th and 10th century translation movement from Greek into Arabic, which was extensively discussed by Dimitri Gutas in his Greek Thought, Arabic Culture (1997). As a result of the translation movement, elements of Greek philosophy and science were permanently incorporated into the philosophical and scientific apparatus of the Islamic world. Muslim thinkers in subsequent centuries had therefore reason to return to the Arabic translations of Greek material or even the original Greek texts themselves in order to clarify their thought. Gutas considers the translation of two ancient Greek texts into Arabic at the court of Mehmet the Conqueror as manifestations of this wider phenomenon.

The translated texts were Ptolemyʼs Geography (a manual on world cartography); and the Chaldean Oracles (a pagan revelation in dactylic hexameter that assisted the purposes of theurgy - a term used already in antiquity to describe various types of religious veneration that combined philosophy with divination and magical practice).

A printed map from the 15th century depicting Ptolemy's description of the Ecumene.  
Islamic cartographers inherited Ptolemy's Almagest and Geographia in the 9th century which is said to have stimulated an interest in geography and map-making. Muslim scientists then made many of their own contributions to geography and the earth sciences. 

If one follows modern criteria in order to decide to which intellectual categories these two texts belong, the Geography belongs to hard science, whereas the Chaldean Oracles to superstition or philosophical eccentricity at best. They can therefore be considered as disconnected events.

However, the lecture argues that they were part of the same coherent intellectual agenda pursued by a number of Muslim intellectuals on Mehmet the Conquerorʼs payroll. These intellectuals were not interested in ancient philosophy and science as such, but in the Byzantine reception and reiteration of ancient Greek philosophy and science in its fifteenth century form. The advantage of preferring the Byzantine reiteration is its incorporation, since the 9th century, of references to its Islamic counterpart.

Evidence for the Ottoman interest in Byzantine (as opposed to ancient Greek) philosophy and science is the fact that the Arabic translation of the Chaldean Oracles is part of an anthology of texts written by Georgios Gemistos Plethon the most extensive excerpts of which are from Plethoʼs Book of Laws. Further, several manuscripts in the Greek and Arabic manuscript collection of the Topkapi palace contain texts that discuss the same topics as the Geography and the Plethonic anthology.

The Greek-into-Arabic translation of the Geography is not necessarily limited to assisting cartographic projects.

Ptolemy meant the Geography as a companion volume to the Almagest (his astronomical manual), the Tetrabiblos (his astrological one), and the Handy Tables (used for both astronomical and astrological purposes).

It is therefore an instrument in the service of the mathematical sciences which, in the medieval and early modern world, whether East or West, included both astronomy and astrology.

Georgius Gemistus Plethon
or Pletho was a scholar of Neoplatonic philosophy.

For example, Ptolemyʼs Geography can help
convert how an astronomical phenomenon sighted and recorded in a given part of the world would have been visible in another. Such a conversion can help predict and describe planetary motion which, in modern terms, is an astronomical project; but since the position of the planets is taken into consideration when casting a horoscope, the Geography can also help with astrological pursuits. The sighting of celestial phenomena can also help the calculation of dates in world chronology and therefore also the compilation of apocalyptic literature that draws from world history.

This evidence accords well with what we know from non-Greek sources. Around the time of Constantinopleʼs conquest by the Ottomans, the air is rife with apocalypse. From a Muslim point of view, the conquest fulfills a promise articulated in the Quran that Constantinople, in spite of its successful resistance in the seventh century, is destined to ultimately succumb to Islam.

A number of texts of Muslim provenance demonstrate this climate in the course of the fifteenth century. As Cornell Fleischer recently discussed, “The most comprehensive of these -and, in terms of production, verifiably datable-  was the Miftah al-jafr al-jamiʼ [The Key to the Comprehensive Prognosticon] of ʽAbd al-Rahman al-Bistami (d. 1454-5). A compendium of apocalypses current in Mamluk lands in the fourteenth and fifteenth centuries with some materials drawing on Crusade-era traditions, the Key also contains several prophetic works attributed to Ibn ʽArabi and given definitive literary form by Bistami; it [later] became [...] the Urtext from which the image of Sultan Süleyman as Mahdi, or saintly cosmocrator, would be hewn.”

The Arabic translation of Plethoʼs work also fits within this general climate. Not only the Chaldean Oracles but the entire collection of his excerpts included in the Arabic anthology are very much those that would have assisted the purposes of theurgy. This was a prime purpose for which the Chaldean Oracles had been employed to since antiquity, and miracles performed with their help (or with the help of prophecy and magic of Chaldean inspiration) are recorded in ancient literature in connection with major and minor Neoplatonic figures. Many involve relief from rain, a concern particularly urgent in the course of ancient and medieval military campaigns and apparently a top priority for Mehmet the Conquerorʼs administration, since the repair of Constantinopleʼs water supply system became one of its most urgent tasks soon after 1453.

The Arabic translation of Pletho is informed by its philosophical context both in the Greek and the Arabic speaking world. By translating prayers and hymns to the ancient gods (that cannot be dissociated from their connection with the planets already made in the context of Babylonian astrology and exported to the Graeco-Roman world since antiquity) the Arabic translator of Pletho is enriching a pre-existing Arabic literature on the same topic.

The most famous such example (and the only published one) is, perhaps, the eleventh century Andalusian book on magic known as the Ghayat al-hakim (translated into Latin already in the Middle Ages under the title Picatrix), which contains a long chapter describing the Sabian ritual practices for “procuring the powers of the planets”.

Aristotle teaching; detail from of an Arabic document in the British Library.  

Proof that the Arabic translator of Plethoʼs texts is aware of the Hermetic literature in Arabic and views Pletho in its context are the translators introductory remarks: there, he designates Pletho as “pagan” (wathani, literally “worshipper of graven images” or “idols”) and further clarifies with the epithet Sabean (sabi).

These characterizations of course reflect the accusations of paganism leveled against Pletho by Georgios Gennadios-Scholarios, the first patriarch of Constantinople under Ottoman rule appointed by Mehmet the Conqueror, which led to the public burning of the Book of Laws by 1462. More importantly, they convey the Arabic and Islamic context within which Plethoʼs texts can be rendered meaningful and useful.

In a medieval Arabic and Islamic context, the Sabeans are pagan star worshippers the licit existence of whom within an Islamic polity (and therefore their right to adhere to their religion without converting to Islam) is guaranteed by the Quran. In the 9th and l0th centuries a few among them are known as prominent scientists and translators of Greek material into Arabic, including Hermetic material, such as Thabit Ibn Qurra and his son Sinan, though by the 12th century they seem to have disappeared as a living community. The question of who exactly they were, what they believed, and what their connection with the Graeco-Roman heritage and its transfer into Arabic was, is a complicated and inconclusive one in modern scholarship, but need not occupy us right now. To a 15th century educated Muslim “Sabean” would have meant a pagan with a licit existence among Muslims, whose knowledge and rituals can assist in magic and divination.

Mehmet the Conqueror interested in ancient greek philosophy and science through arabic translations.
It is clear that a good part of the collection of Greek manuscripts in the Topkapi palace fits the same research agenda. In 1983 Julian Raby showed that the Greek manuscipts at the Topkapi are in fact a collection copied or otherwise acquired for the court of Mehmet the Conqueror and his successors at least down to 1520, the date of the latest known Ottoman firman issued in Greek to a European state.

Of the sixteen MSS examined by Raby that were demonstrably produced in Mehmet the Conquerorʼs Greek scriptorium, at least five (about one third of the total) contain texts that could be associated with prophecy, apocalypticism, and research in the occult: prophecies of Hippocrates discovered in his grave; on precious stones and the properties of animals; the Testament of Solomon, a classic of magic that explains how to manipulate demons; antiquities of Constantinople (I hasten to remind that antique statuary played an important role in both medieval Greek and Arabic magic); Arrianʼs account on Alexander the Great.
Mehmet the Conquerorʼs desire to model himself after Alexander (a figure, after all, that appears in the Quran and is vaunted in voluminous Arabic and Persian lore) is well recorded. Further, Alexander played an important role in medieval apocalyptic tradition, both East and West, since his reign is viewed as a terminus in the revolution of the worldʼs ruling dynasties. Two more Greek manuscripts, not copied at Mehmetʼs scriptorium but belonging to the Topkapi collection, cover divination through physiognomy.

Overall, the larger questions that we know the Muslim scholars at the court of Mehmet the Conqueror were interested in correspond well with topics covered in the Greek holdings of his library, as well as the Greek-into-Arabic translations prepared during his reign. These questions include the following: heliocentrism and a moving earth (both of would soon become key elements to Copemicusʼ astronomical “revolution”); the journey of the soul outside the body; miracles; the unity of God (not only in order to address the complicated theology of the Trinity in the course of Christian-Muslim apologetics, but also to independently help clarify Muslim doctrine); the necessity of Godʼs existence; what constitutes polytheism; the theory and practice of the philosophical notion of “sympathy” (i.e. the idea that something which happens in one part of the universe affects other things everywhere else).

Investigating in which ways ancient Greek and Byzantine philosophical and scientific ideas were picked up in an Ottoman context is important in order to understand what transformations of the Greek and Byzantine material led to its survival.

Maria Mavroudi (born 1967) is a history professor at University of California, Berkeley.
Fluent in classical Greek and Arabic, she also understands Coptic, Latin, and Syriac, and speaks modern Greek and English fluently.
She formerly taught at Princeton University.