The translation of scientific texts from Greek and Arabic in the twelfth and thirteenth centuries is both a symptom and a cause of one of the greatest shifts in Western science. In the twelfth century, Toledo became the center for the translation of scientific works, and the separate streams of mathematical, medical, and philosophical translations were united there. Jews played an important role both in circulating and in translating scientific works in Christendom. The motivation for the translations was the perceived lacunae in Latin scientific education, as Burgundio of Pisa and the biographers of Gerard of Cremona both state. If the goal of the translators was to restore the ancient learning of Euclid, Ptolemy, Aristotle, and Galen, they had two sources: the centers of Greek and Arabic learning. For translations to be made, either the Latin scholar must go in search of the texts or the texts must be sent or brought to the Latin center of learning.