Nicomachus of Gerasa in Spain, Circa 1100: Abraham Bar Ḥiyya's Testimony

In the 1120s, the Jewish philosopher and scientist Abraham Bar Ḥiyya (d. ca. 1136) wrote a Hebrew encyclopedia, Yesodei ha-tevunah u-migdal ha-ʾemunah a detailed chapter on mathematics is extant from this work. One source of its account of the nature of number has long been known to be Nicomachus of Gerasa's Introduction to Arithmetic. Three Arabic versions of Nicomachus are known to have existed: Ḥabib Ibn Bahrīz's translation from the Syriac, now lost; al-Kindī's revision of the latter, lost in Arabic but extant in a Hebrew translation by Qalonymos ben Qalonymos; and Thābit Ibn Qurra's translation from the Greek. A close comparison of Bar Ḥiyya's text with the others and with the Greek original leads to the conclusion that Bar Ḥiyya used Ḥabib Ibn Bahrīz's Arabic translation in its unrevised form and had no contact with Thābit Ibn Qurra's translation.