the Greeks and Syrians and a most learned physician of men’s bodies. He was indeed orthodox in his opinions, as the ‘Prologue’ bears witness, but in morals corrupt, depraved, and stained with lust and avarice” (Bar Hebraeus. ed. Abbeloos et Lamy. i. 205-7). In the same century lived _Ahudemmeh_ who became bishop of Tagrit in A.D. 559, and introduced the commentary of John Philoponus as the regular manual of instruction amongst the Syriac speaking Monophysites. He is said to have composed treatises on the definitions of logic, on the freedom of the will, on the soul, on man considered as a microcosm, and on the composition of man as of soul and body, this last in part preserved in MS. Brit. Mus. Addit. 14620. Amongst the Nestorian scholars of the sixth century was _Paul the Persian_ who produced a treatise on logic which he dedicated to King Khusraw and has been published in M. Land’s _Analecta Syriaca_ (iv). This has brought us to the period of the Muslim invasion. In 638 Syria was conquered, and the conquest of Mesopotamia followed in the course of the same year, that of Persia four years later. In 661 the Umayyad dynasty of Arab rulers was established in Damascus; but all this did not greatly affect the internal life of the Christian communities who lived on in perfect liberty, subject only to the payment of the poll tax. About 650 the Nestorian Henanieshu´ wrote a treatise on logic (cf. Budge: _Thomas of Marga_. i. 79) and commented on John Philoponus. The Monophysites had no great schools like the Nestorians, but their convent at Qensherin, on the left bank of the Euphrates, was a great centre of Greek studies. Its most famous product was _Severus Sebokt_ who flourished on the eve of the Muslim conquest. He was the author of a commentary on Aristotle’s _Hermeneutica_ of which only fragments survive, of a treatise on the syllogisms of the _Analytica Priora_, and of epistles dealing with terms used in the _Hermeneutica_ and on the difficult points in Aristotle’s _Rhetoric_ (cf. Brit. Mus. Add. 14660, 17156). In astronomy he wrote on “the Figures of the Zodiac” and on “the Astrolabe,” the former of these is preserved in Br. Mus. Add. 14538 and has been published by Sachau (op. cit.), the latter in Berlin MS. Sachau 186 and published by Nau in the _Journal Asiatique_ of 1899. Athanasius of Balad who became Monophysite patriarch in 684 was a pupil of Severus Sebokt, and is chiefly known as the translator of a new Syriac version of Porphyry’s _Isagoge_ (Vatican Ms. Syr. 158. cf. Bar Hebraeus _Chron. Eccles._ ed. Abbeloos et Lamy. i. 287).