He was a Franciscan friar who developed an anti‐papal theory of the state, denying the pope secular authority and was excommunicated in 1328, living thereafter in Munich under Emperor Louis IV’s protection. His form of nominalist philosophy saw God as beyond human powers of reasoning, and things as provable only by experience or by (unprovable) scriptural authority. Hence his famous maxim, ‘Ockham’s razor’, that the fewest possible assumptions should be made in explaining a thing.