independent investigation. Of the former class Berthelot gives three specimens, the Books of Crates, of al-Habid, and of Ostanes, all representing the Greek tradition which flourished at Alexandria on the eve of the Muslim invasion.
Whilst the Alexandrians kept alive an interest in medical and the allied sciences the separated branches of the vernacular speaking churches of Asia were more interested in logic and speculative philosophy. It was perhaps natural that the Monophysites with their strong Egyptian connection should adopt the commentaries of John Philoponus, himself a Monophysit of a type, but both they and the Nestorians invariably used Porphyry's Isagoge as an introductory manual. In the general treatment of metaphysics and psychology as applied to theology, and in the treatment of theology itself, the Monophysites inclined more towards neo-Platonism and mysticism than the Nestorians, and their life centered more in the monasteries, whilst the Nestorians adhered rather to the older system of local schools, although they too had monasteries, and in course of time the schools adopted the discipline and methods of the convent.
The oldest and greatest of the Nestorian schools was that of Nisibis, but in A.D. 550 Mar Ahba, a convert from Zoroastrianism, who had become catholicos or patriarch of the Nestorians, established a school at Seleucia on the model of Nisibis. A little later the Persian king, Kusraw Anushirwan (Nushirwan, flor. 531-578 A.D.) who had been greatly impressed by the
