Occam or Oakham, William of, an English Scholastic philosopher, born at Oakham, Surrey, surnamed Doctor Invincibilis; was a monk of the order of St. Francis; studied under Duns Scotus (q.v.), and became his rival, and a reviver of Nominalism (q.v.) in opposition to him, by his insistence on which he undermined the whole structure of Scholastic dogmatism, that is, its objective validity, and plunged it in hopeless ruin, but cleared the way for modern speculation, and its grounding of the Objective (q.v.) on a surer basis (1280‒1347).
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Obsidian * Occasionalism