This dissertation examines how scholars in eleventh-century Constantinople and Antioch (under Byzantine rule, 969-1084) understood matter and its transformation. It argues that matter, a concept inherited from ancient philosophy, continued to be a fertile and malleable idea-complex endowed with cultural and religious meaning in medieval thought-worlds of the Eastern Mediterranean.

The first three chapters form a case study on the unpublished Arabic translations of late antique Christian texts by the 11th-century Byzantine Orthodox deacon ʿAbdallāh ibn al-Faḍl of Antioch (fl. ca. 1052). They proceed by increasing specificity: chapter 1 surveys Ibn al-Faḍl's Greek-to-Arabic translations; chapter 2 turns to one of these translations, of a famous and highly influential commentary on the first chapter of the Book of Genesis by Basil of Caesarea (ca. 330--?379), his Homilies on the Hexaemeron; and chapter 3 reads Ibn al-Faḍl's marginalia to his translation of Basil's Hexaemeron. Together, they provide insight into a culturally Byzantine milieu in which the primary language of communication was Arabic, exploring how intellectuals in that context understood matter, where this understanding came from, and why it resonated in this city at the edge of the empire.

A second case study, on Byzantine alchemy, is the subject of chapter 4, which focuses on the earliest extant Greek alchemical manuscript (10th/11th century). It argues that this manuscript can be a rich source not only for ancient alchemy but also for its Byzantine reception and appreciation. Just as translation reshapes and repackages an ancient work for new contexts, so too this manuscript's transmission and compilation sheds light on how alchemical texts ranging in date from late antiquity (and perhaps earlier) to the ninth century (and perhaps later) were read, understood, and repurposed in the middle Byzantine period in the empire's capital.