Rabbi Isaac Canpanton, the Gaon of Castile רבי יצחק קנפנטון

He lived more than a hundred years and died at Penafiel twenty nine years before the expulsion, and in his lifetime he was called the Gaon of Castile, a title no one else in the Spain of those years bore.

The book he left is small and unlike the others. Darkhei haGemara expounds no law at all: it expounds reading. Why this word stands here and not another; what a disputant was bound to say and what he deliberately left unsaid; which objection answers an argument and which one replaces it. He demanded of a pupil not memory but an understanding of the order of thought, and for the same reason told him to understand another man's position first and only then to argue with it.

In Zamora, where he kept his yeshiva, Rabbi Isaac Arama was preaching in those same years. Out of Canpanton's school came the last generation of Castilian teachers, and through them his way of study passed overseas: in the yeshivot of sixteenth century Salonika and Safed the arguing is already Castilian, though for Jews Castile itself is no more.