As Israel Ta-Shema noted in 1993, the “medieval Hebrew book […] often seems perplexingly left in mediis rebus and intrinsically incomplete”. By this he points out the phenomenon of fluidity and flexibility in medieval Hebrew manuscripts, being in a state of an ‘open book’– emphasizing the dynamic state of the text and its transformational character. Do these insights apply to medieval Hebrew mathematical texts? Do they form a special sub-class of texts? In order to examine this question, I will look into the history of copying, transmission and reception of one of the first mathematical manuscripts in Hebrew written in the 12^th century by Abraham bar Hiyya: “A treatise on measurement of areas and volumes”  (“Ḥibbur ha-Meshiḥa ve-ha- Tishboret”), a text which was later translated into Latin in 1145 as “Liber embadorum”. With this manuscript I aim to examine, whether there were special characteristics of the transfer of knowledge, seen with the various copying and the translation practices, considering medieval Hebrew (and Latin) mathematical texts. 

Michael Friedman is a historian of mathematics and a post-doc at the excellence cluster “Matters of Activity” of the Humboldt University, Berlin. The focus of his research is on how material, visual and symbolical knowledge and practices in mathematics interact with each other. More specifically, his research examines the material practices of mathematics (folding, weaving, braiding, knotting, as well as three-dimensional models) and how symbolical-mathematical knowledge was prompted by them. Selected publications: “Haüy, Weiß, Fröbel: the influence of nineteenth-century crystallography on the mathematics of Friedrich Fröbel’s kindergarten” (Paedagogica Historica, 2021); and: A History of Folding in Mathematics. Mathematizing the Margins (Birkhäuser, 2018).