William of Ockham

William of Ockham was an English Franciscan friar and philosopher who became the foremost proponent of nominalism — the view that universal concepts are mere names, not real entities existing independently of the particular things that instantiate them. His principle of parsimony, known as Ockham's Razor, holds that entities should not be multiplied beyond necessity, and has become one of the most widely applied heuristics in philosophy and science.