THIS ESSAY was written for a conference on why science made so few inroads into medieval Ashkenazic culture. The scientific corpus was readily available in the Middle Ages, and some of it seems to have circulated in Ashkenaz, yet it remained without cultural resonance. I was surprised to be invited to this conference since, as I told its organizers, I knew nothing about science in Ashkenaz. However, I added that the phenomenon of cultural isolation held true for Ashkenaz even in halakhah, and they asked me whether I would give a presentation on that. The following paper was the result. As noted below, I drew freely here on previous studies, and whatever merit the essay has lies in the recasting of old material (together with some new data) to portray to what degree Ashkenaz chose to be indifferent to the accomplishments of other halakhic cultures.

I HAVE NO GOOD TIDINGS |41| to bring to the conference. Indeed, I have, perhaps, no tidings at all. I know nothing about science in Ashkenaz, nor in any other Jewish culture for that matter. I can speak only of matters halakhic, and can only point out the isolation of Ashkenaz in that area, too.

Let me begin at the end. The lights were going out for the Jews in Ashkenaz in the closing years of the thirteenth century. They were expelled from England in 1290, and from the royal kingdom of France in 1306. In Germany, the collapse of the strong imperial government exposed the Jews to two murderous waves of pogroms, that of the Good Werner in 1287 and the Rintfleisch in 1298, which devastated some 140 Jewish communities. R. Me’ir of Rothenburg was imprisoned in 1286 and lingered in confinement for a decade until his death in 1293. His pupil, R. Mordekhai, fell victim to the Rintfleisch massacres, and his other famed pupil, R. Asher, fled south with his young son, the future author of the Arba’ah Turim, and in 1306 he became the rabbi of the Jewish community of Toledo in Spain.

In Toledo, Rabbenu Asher penned his famous Sefer Pesakim. A generation later, his son, R. Ya’akov, authored the classic Arba’ah Turim (more commonly called simply Tur) which formed the basis of the famous sixteenth-century code, the Shulḥan ‘Arukh.