Hellenic philosophy died a lingering death even before Islam appeared. The Christianization of the Roman empire, and the increasing self-identification by the Greek-speaking population as Romans in the so-called Byzantine age, rendered Hellenic philosophy the object of scorn. By the end of the 6th century, philosophy was neither practised nor taught, nor were philosophical texts copied. In addition, all Greek texts, and not only the philosophical ones, went through two periods of sifting in their physical transmission—from papyrus rolls to codices (3rd–4th centuries) and from uncial writing to minuscule script (8th–9th centuries)—at the end of which only a small fraction survived.
By late antiquity the Hellenic philosophical and scientific corpus had been organized into a potent curriculum, based on the classification of the sciences originally introduced by Aristotle, which represented the sum total of human knowledge. It was received as such by the Hellenized peoples of the Near East, who had been participating in the philosophical enterprise in Greek. As the practice of philosophy attenuated in the Greek-speaking world, Persians in the Sasanian empire, and Arameans, now Christianized into the churches of the East, began translating selectively parts of the philosophical curriculum into Middle Persian and Syriac, respectively. With the emergence of Islam in the 7th century and the subsequent development of scholarship in Arabic, political, social, and cultural exigencies required that the rulers of the new empire participate, own, and promote the high Hellenic culture cultivated amid the Persian- and Syriac-speaking subjects. As a result there was launched a far-flung translation movement into Arabic, from Sanskrit, Middle Persian, Syriac, and especially from Greek, of all sciences and philosophy. The philosophical texts that passed into Arabic were primarily the Aristotelian corpus, the near-totality of which was translated with some notable omissions, and the long list of commentators from Alexander of Aphrodisias to the last Neoplatonists of Alexandria. The Platonic tradition was not favoured, Platonism having been proscribed in Greek, and to a lesser degree in Syriac, Christianity. Not a single complete dialogue was translated into Arabic; what was available of Plato was various selections from the dialogues, Galen’s summaries of the dialogues, biographies, and sayings. Selections from Plotinus and Proclus were available in paraphrastic and interpolated versions that were attributed to Aristotle. The remaining schools of Hellenic philosophy, already extinct long before the rise of Islam, were known primarily through quotations among the translated authors like Aristotle and Galen.