The ArgumentIt is well known that theTractatusof Peter of Spain (later Pope John XXI) was one of the most popular logic textbooks in the Middle Ages and early Renaissance. Less known is theTractatus'sconsiderable reputation and diffusion among the Jews, as evidenced by five translations, two commentaries, and what appears to be anabbreviatio— if not of theTractatusitself, then of a similar work. The present article attempts to understand the phenomenon of theTractatus'spopularity and offers an analysis of the three translations whose authors (...) are known — those by Shemaryah ha-Ikriti (Greece, early to mid-fourteenth century), Abraham Abigdor (late fourteenth century), and Judah b. Samuel Shalom (either Italy or Spain, mid-fifteenth century) — and their subsequent fate. The more popular versions of Abraham Abidgor and Judah Shalom provided Jewish students, many of whom would likely become physicians, with a grounding in logic comparable to that of their Christian counterparts. (shrink)