Their school at Resaina is known from the name of Sergius, one of the first of these translators, in the days of Justinian; and from their monasteries at Kinnesrin (Chalcis) issued numerous versions of the introductory treatises of the Aristotelian logic. To the Isagoge of Porphyry, the Categories and the Hernieneutica of Aristotle, the labours of these Syrian schoolmen were confined.
All that is wanting in his writings, especially in his Isagoge in artem analyticam (1591), in order to make them look like a modern school algebra, is merely the sign of equality - a want which is the more striking because Robert Recorde had made use of our present symbol for this purpose since 1 557, and Xylander had employed vertical parallel lines since 1575.
Allgemeines historisches Lexikon (Leipzig, 1709 ff.); Historia Ecclesiastica Veteris Testamenti (4 vols., Halle, 1709); Elementa Philosophiae Practicae, Instrumentalis, et Theoreticae (3 vols., 1697); Selecta Juris Naturae et Gentium (Halle, 1704); Miscellanea Sacra (3 vols., Jena, 1727); and Isagoge Historico-Theologica ad Theologiam Universam, singulasque ejus pales (2 vols., 1727).
It takes form as a body of doctrine drawing its premises from authority, sometimes in secular matters from that of Aristotle, but normally from that of the documents and traditions of systematic theology, while its method it draws from Aristotle, as known in the Latin versions,' mainly by Boethius, of some few treatises of the Organon together with the Isagoge of Porphyry.
Under him Avicenna read the Isagoge of Porphyry and the first propositions of Euclid.
Joachim Jung, in his Isagoge phytoscopica (1678), recognized that the plant-body consists of certain definite members, root, stem and leaf, and defined them by their different form and by their mutual relations.
Of the commentaries we have - (1) one on the Isagoge of Porphyry (Venice, 1500 fol.); (2) one on the Categories (Venice, 1503 fol.), the authenticity of which is doubted by Brandis; (3) one on the De Interpretatione (Venice, 1503 fol.).