Ludovicus, as I pointed out in my previous post, the arabs had access to classical culture by conquering the eastern roman territories in middle east and egypt: it means that without the eastern roman empire surviving the germanic invasions and fall of the west in the Vth and VIth centuries, the arabs would have found very few of classical civilization because a lot would have been lost.
While it's true that important scientific advances were made by medieval muslims this has less to do with the saving classic civilization and more to do with their own scientific effort and it doesn't mean that most of classic culture was saved by them.
In the following article it explain that the byzantine contribute to the revival of classic studies in Europe wasn't secondary at all (although exagerated by past scholars) and shows how few of the classic heritage was still unknown in Europe in the XVth century.
Thus the Greek emigres who reached Italy during the fifteenth century were by no means all scholars: they ranged from exiled royalty to carpenters and mercenaries. Yet there can be no doubt that some of them played an important part in spreading a knowledge of the classical Greek language and ancient Greek literature in Italy. There was a good reason for this: reading classical Greek and even composing in the same style were an integral part of Byzantine higher education. Whereas in the West secular education had tended to die out in the early Middle Ages, in Byzantium it was sustained. In each generation, those who took their education beyond the age of fourteen would be instructed in the works of the ancient Greek poets, historians, dramatists and philosophers. Thus any educated Byzantine in the imperial service would have had a knowledge of these works which would have been the envy of many educated Italians, who were now starting to take an interest in ancient Greek literature (Constantinides, 1-2). Manuel Chrysoloras arrived in Italy at the end of the fourteenth century. He came not as a teacher or a scholar, but as an envoy of the Byzantine emperor, charged with negotiating western assistance for the beleaguered empire. In 1391, however, while staying in Venice, he gave some lessons in Greek to a certain Roberto Rossi, who then passed an enthusiastic account of his teacher to Coluccio Salutati (1331-1406), the Chancellor of Florence. So impressed was Salutati that he decided to secure Chrysoloras's services, and in 1396 invited him to teach grammar and Greek literature at University of Florence. Chrysoloras only occupied this post between 1397 and 1400, but in that period had a tremendous effect. Among his pupils were numbered some of the foremost figures of the revival of Greek studies in renaissance Italy, including Guarino da Verona (1374-1460) and Pallas Strozzi (1372-1462). Chrysoloras was not the only one to receive such a welcome. When George Gemistos Plethon attended the Council of Florence in 1439, his lectures on the differences between the work of Plato and Aristotle were eagerly received and prompted the later comment of Marsilio Ficino (1433-99) that Plethon had brought the spirit of Plato from the Byzantine empire to Italy (Thompson, 78; Setton, 57-8; Brown, 389-90; Woodhouse, 171-88). The success of Chrysoloras and Plethon cannot have gone unnoticed by other members of the Byzantine ruling classes, eager to escape to the West, and others were soon following in his footsteps. John Argyropoulos, an official in the service of one of the rulers of the Byzantine Morea, was sent to Italy in 1456 on a diplomatic mission. He too was offered the chance to teach in Florence and he accepted with alacrity, remaining in Italy until his death in 1487. Other cities also attracted Byzantines to teach Greek: Theodore Gaza of Thessalonica taught at Ferrara, Naples and Rome, Demetrius Chalkondyles of Athens at Padua, Florence and Milan (Geanakoplos, Constantinople and the West, 72-87, 91-113; Geanakoplos, 'The discourse', 118-44; Harris, Greek Emigres, pp. 122-3). Of no less importance than the teaching activity of these individuals, however, were their translations from Greek into Latin. Early in the fifteenth century, Manuel Chrysoloras co-operated with Uberto Decembrio (d.1427) to produce a Latin version of Plato's Republic, and in Rome the process of translation was specifically encouraged by Popes Nicholas V (1447-55) and Sixtus IV (1471-84). Under papal patronage, George of Trebizond produced Latin versions of Plato's Laws and, together with Theodore Gaza, of a large part of the Aristotelian corpus. The availability of these texts in Latin opened them up to a much wider readership (Monfasani, Collectio, 698-754; Geanakoplos, Constantinople and the West, 79-82; Wilson, 76-8; Setton, 78-80).
THE DEBATE OVER PLATO
In addition to teaching and translating, the Byzantine scholars were also at the centre of the debate over the merits and meaning of works of the ancient Greek philosophers, particularly those of Plato. Unavailable in western Europe for most of the Middle Ages, Plato's works were now much more accessible thanks to the Latin translations of Manuel Chrysoloras, George of Trebizond and others. Renaissance Italy was particularly receptive to the ideas of Plato because political attitudes had been changing during the fifteenth century, as interest in the values which had been used to underpin the traditional concept of citizenship declined. In the past, the highest duty of the citizen had been considered to be that of involving himself in civic affairs, a notion that is prominent is the works of Cicero and Aristotle. Now a life of contemplative withdrawal and disengagement from political life was coming to be seen as praiseworthy. Politics were to be left rather to those who had been educated to pursue them, among whom the ruler or the prince was paramount. It is no coincidence that the later fifteenth century saw the writing of numerous `mirrors of princes', such as Niccol