At RealClearWorld Peter Adamson explains the service to the world performed by Arab scholars of the 9th century CE:
In the eastern part of the Roman Empire, the Greek-speaking Byzantines could continue to read Plato and Aristotle in the original. And philosophers in the Islamic world enjoyed an extraordinary degree of access to the Hellenic intellectual heritage. In 10th-century Baghdad, readers of Arabic had about the same degree of access to Aristotle that readers of English do today.
This was thanks to a well-funded translation movement that unfolded during the Abbasid caliphate, beginning in the second half of the eighth century. Sponsored at the highest levels, even by the caliph and his family, this movement sought to import Greek philosophy and science into Islamic culture. Their empire had the resources to do so, not just financially but also culturally. From late antiquity to the rise of Islam, Greek had survived as a language of intellectual activity among Christians, especially in Syria. So when Muslim aristocrats decided to have Greek science and philosophy translated into Arabic, it was to Christians that they turned. Sometimes, a Greek work might even be translated first into Syriac, and only then into Arabic. It was an immense challenge. Greek is not a semitic language, so they were moving from one language group to another: more like translating Finnish into English than Latin into English. And there was, at first, no established terminology for expressing philosophical ideas in Arabic.
Unfortunately, the story did not end there and Mr. Adamson does not go on to explain the sequelae. A tragedy occurred.