The Thomist school grew from the consequences of the penetration into the Paris University around the middle of the twelfth century of the vast corpus of Aristotelian science and philosophy through the medium of Arabic and Jewish schools (also writing in Arabic) in Spain and Sicily.SOURCE: In the Wake of the Plague: The Black Death & the World It Made, by Norman F. Cantor (Harper Perennial, 2002), pp. 116-117
The Aristotelian corpus was translated in the eastern Mediterranean by Byzantine monks and Arab Muslim scholars into Arabic between 800 and 1000 and found its way, accompanied by various mathematical and medical texts, into Cordoba, Spain, and Palermo, Sicily, by 1050. Previously only Aristotelian logic was available in the West, which was thoroughly dominated by the Platonic idealistic and mystical rather than the Aristotelian scientific and rational frame of thought. By the middle of the thirteenth century Aristotle's writings were being translated directly from Greek into Latin rather than through Arabic mediation, and these improved translations were available to the corpulent and good-humored Dominican friar at Paris, Thomas Aquinas.
What drove the Thomist mission was a concern that Catholic doctrine was founded on the Bible, church authority, and the more mystical and irrational part of ancient culture, not on reason and Aristotelian science. It was to defend this established faith and high culture--something that the Cairo rabbi Maimonides had already attempted for Judaism, to deep resentment from the Orthodox rabbinate--that Thomas Aquinas, following his Parisian Dominican mentor Albert the Great, set out to show the large-scale compatibility of Catholic faith and Aristotelian reason and science.