ASHER BEN YEḤIʾEL (c. 1250–1327), known as Rabbenu ("our teacher") Asher or as RʾoSH, the acronym of that epithet; Talmudist and rabbinic legal authority. Born and educated in Germany, Asher was the leading disciple of the outstanding German rabbinic scholar of his age, Meʾir ben Barukh of Rothenburg. The turbulence disrupting German Jewish life impelled him to emigrate in 1303. He eventually settled in Toledo; that a man of such alien background was accepted as head of the Toledo rabbinical court reflects the power of his learning and his personality.

In Spain, Asher was immediately embroiled in a Kulturkampf over the study of philosophy. The product of an exclusively Talmud-centered curriculum, he did not fully understand all the issues involved (he declined to answer a legal query concerning the astrolabe...