William of Sherwood

William of Sherwood or William Sherwood (Latin: Guillielmus de Shireswode; c. 1200 – c. 1272), with numerous variant spellings, was a medieval English scholastic philosopher, logician, and teacher. Little is known of his life, but he is thought to have studied in Paris, was a master at Oxford in 1252, treasurer of Lincoln from 1254/1258 onwards, and a rector of Aylesbury.

He was the author of two books which were an important influence on the development of scholastic logic: Introductiones in Logicam (Introduction to Logic), and Syncategoremata. These are the first known works to deal in a systematic way with what is now called supposition theory, known in William's time as the logica moderna.