Gesius’ Commentaries on Galen: Recovering lost works through a mixed-method approach

Palimpsests have yielded spectacular new discoveries in the area of ancient texts: hitherto lost works are recovered and can be read again. We recently identified a set of five palimpsests which will radically change the way in which we view the history of medicine in late antique Alexandria and the transmission of medical knowledge from Greek via Syriac into Arabic. These palimpsests contain Commentaries by Gesius (ca. 450–530s) in Syriac translation on two works by the famous Greek physician Galen (ca. 129–216), namely Mixtures and Natural Faculties. Gesius emerged as the most prominent of the iatrosophists or professors of medicine in late antique Alexandria, a period that had a tremendous impact on the subsequent tradition, both east and west. Mixtures and Natural Faculties belong to the so-called Sixteen Books of Galen, which formed part of the core curriculum in the amphitheatres of the iatrosophists. Moreover, the palimpsests also contain the Syriac version of Galen’s texts.By using a mixed method approach, we propose to make the erased texts readable again, and then edit, translate and study them. Combining multispectral image capture and analysis with machine learning techniques, we will be able to transcribe these lost texts in full and, in the process, reconstruct the original manuscript. We shall study Gesius’ works in the context of medicine in late antique Alexandria and place it in a tradition where commentaries, abrigments, branch diagrams and encyclopaedias were all employed to impart medical knowledge. Finally, these Syriac translations offer us an opportunity to study how the Sixteen Books of Galen were transmitted into Syriac, and what role they played in Graeco-Arabic translations. We will thus study Gesius’ role as the chief medical authority in Alexandria and his subsequent influence, in order to judge his place in history on the basis of his own writings for the very first time.