Practices of Textual Changes in Medieval Mathematical Manuscripts

The Case Study of the Division of Geometric Figures in Ḥibbur ha‑ Meshiḥah ve‑ha‑Tishboret and Liber embadorum

Abstract

One of the well-known medieval mathematical treatises written in Hebrew is Rabbi Abraham
bar Ḥiyya’s Ḥibbur ha-Meshiḥah ve-ha-Tishboret, composed between 1116 and 1145. The Ḥibbur
survives in (at least) eight manuscript copies, produced between the fourteenth and the sixteenth
centuries, as well as in a Latin translation titled Liber embadorum, made in 1145 by Plato of Tivoli.
Of the latter, five extant copies from the fifteenth and the sixteenth centuries are known. While the
Latin translation adheres to the general structure of the Ḥibbur, it also exhibits specific changes
that are indicative of the historical development of both the Hebrew and the Latin texts. By focusing
exclusively on the extant manuscripts – rather than on any endeavor to (re)construct a history of
the Urtext, whether in Hebrew or Latin – one can observe not only various omissions, comments,
and notes added to the various copies, but also that such changes modify the character of the text,
rendering it less or more practice- or theory-oriented.
What do these additions and omissions reveal about how mathematical texts were regarded in the
fourteenth to sixteenth centuries? Can we draw conclusions about how these texts were read, copied
and used? To answer these questions, this paper examines three sections of the Ḥibbur and Liber
embadorum, all of which concern the study of the division of geometric figures. I argue that a refined
typology of the additions, omissions, added notes, comments and diagrams can help us to see these
manuscripts not as ‘copies’ of an ‘original text’, but as complex mathematical written artefacts in
their own right, each with unique characteristics.