Europe Got Its Homework Back With Corrections
Gerard of Cremona went to Toledo for one book and stayed thirty years. What came back was not a restoration: the texts had been read, argued with and extended in Arabic for five hundred years.
In the middle of the twelfth century an Italian scholar went to Spain looking for one book.
Gerard of Cremona wanted Ptolemy's Almagest, the great work of Greek astronomy, which he knew existed and could not find anywhere in Latin Christendom. He heard there was a copy in Toledo. He went.
Toledo had been taken by Castile in 1085, but its population was still overwhelmingly Mozarab, Jewish and Muslim, and its libraries were intact: centuries of accumulated Arabic scholarship, including the Greek corpus in translation, sitting on shelves.
Gerard found his book. He also found out what else was there, and it changed the rest of his life.
He learned Arabic and stayed thirty years.
By his death in 1187 he had translated eighty-seven works into Latin, an output so large that historians have argued about whether Gerard of Cremona was a man or a workshop trading under one name.