Dangling in the southern winter sky and very visible from my balcony in Naples is the great equatorial constellation of Orion. The second brightest star in that constellation is the red supergiant, Betelgeuse. (This is the first of a few familiar names coming up that no one knows how to pronounce. Another one is "Averroës.") Betelgeuse is 390 light years from my balcony and, thus, remote from the various fields of human conflict that are responsible for my knowing neither the pronunciation nor the original name of the star—thus, our high school astronomy club's cutesy mnemonic of "Beetle Juice." I don't recall ever learning that the name came from the Arabic bayt al jauza, meaning "in the house of the twins," referring to the Heavenly Twins, Castor and Pollux, hanging out right above Orion.
Speaking of high school, I did not do well in mathematics, but I am willing to give Al-Khwarizmi (known to us as Algorizm!) (770 - 840) his credit if he takes a bit of my blame. I will take all the blame for not knowing who Chaucer was talking about in theCanterbury Tales, when, in praising the knowledge of the doctor on the trip, he reminded us that ye olde pilgrim sawbones was familiar not only with Hippocrates and Galen, but "Rhazes, Hali, Averroës and Avicenna."
It is convenient—but not a good idea—to pigeonhole our own cultural history into tidy episodes: The Renaissance, The Age of Reason, The Enlightenment, The This & That, as if they had happened all of a sudden with no connection to anything else—as if Leonardo woke up one fine morning in 1500, looked at his homemade (obviously) hour-glass and said "Gee, it's the Renaissance; I'd better build a helicopter." The point of this entry, then, is simply to draw your attention to how interconnected European and Arabic culture used to be, and how there is a link between the glorious age of Arab science and culture (800-1100) and the beginnings of the Italian Renaissance. (I am not making the post hoc, ergo propter hoc mistake of saying that that which comes first necessarily causes that which comes second. I am simply saying it's a good idea to know what came before you—Bonum est quod ante te evenit scire (I think).
After Islam's rapid spread from Spain to India, Muslims founded the city of Baghdad in 800, and it is here that the Muslim quest for knowledge begins, the manifestation of an insatiable curiosity (to use Einstein's choice phrase from many centuries later) "to figure out how the Old Man runs the universe." It is in Baghdad that the Muslims founded their great school of translation, the incredible ambition of which was to translate as much as they could find of science, astronomy, mathematics, music, geography and philosophy—whatever remained of Classical Greek knowledge. It meant going even further afield—to India—to study the mathematics and philosophy of those who had written in classical Sanskrit centuries earlier.
In 800 this was by no means an easy task. Much classical Greek writing had not survived the centuries of neglect by Christians inimical to "pagan" thought. As early as the year 500, the great library at Alexandria was a ruin and, a few years later, Justinian closed Plato's Academy in Athens because it was a hotbed of pagan (non-Christian) philosophy. Arab scholars, then, translated into Arabic the few Greek texts that remained, or translated from languages into which the Greek originals had previously been translated by scholars who had left Greece for parts east. These were mainly exiled Nestorian Christians from Greece, and Classical Greek scholars from Plato's academy who had fled to Persia, where they founded a great center of learning at Jundishapur (before the coming of Islam) and translated much of their material into Aramaic, the lingua franca of the Middle East at the time. After Baghdad, the Arabs later started equally fine centers of scholarship in Spain at Cordoba and Toledo.
Transmission of this glorious knowledge from the Muslim world into Italy happened primarily through Spain and Sicily; that is, the great courts of learning in Cordoba and the pre-Crusades court of Norman Sicily in the 12th century. It is in Sicily, particularly, that Norman tolerance provided for the coexistence of Byzantine Greek, Italian Christian, and Arab scholars. It was, perhaps, the last great period of human tolerance in European history