During the Later Middle Ages, theologians such as John Duns Scotus (d. 1308)[AH] and William of Ockham (d. c. 1348), led a reaction against scholasticism, objecting to the application of reason to faith. Their efforts undermined the prevailing Platonic idea of "universals". Ockham's insistence that reason operates independently of faith allowed science to be separated from theology and philosophy. Legal studies were marked by the steady advance of Roman law into areas of jurisprudence previously governed by customary law. The lone exception to this trend was in England, where the common law remained pre-eminent. Other countries codified their laws; legal codes were promulgated in Castile, Poland, and Lithuania.

What school of thought was Duns Scotus opposed to?