William of Sherwood

William of Sherwood (c. 1200 – c. 1272) was a medieval English scholastic philosopher, logician, and teacher. Little is known of his life, but he is believed to have studied in Paris and was a master at Oxford by 1252. He also held positions as treasurer of Lincoln from 1254/1258 onwards and as rector of Aylesbury. Sherwood is primarily known for his two books, 'Introductiones in Logicam' (Introduction to Logic) and 'Syncategoremata', which significantly impacted the development of scholastic logic. These works are notable for their systematic treatment of what is now termed supposition theory, referred to in Sherwood's time as 'logica moderna'. His 'Introductiones in Logicam' is the first known work to systematically discuss supposition theory. In it, he introduced a division of supposition into material, formal, and personal, and explored complex cases like confused supposition, addressing problems of multiple generality. His work influenced subsequent logicians and the development of 'terminist logic'. Roger Bacon mentioned Sherwood as one of the "more famous wise men of Christendom," even suggesting he was wiser than Albertus Magnus.