William of Ockham (1288 AD to 1348 AD) was a late Medieval Franciscan philosopher and friar originally from England. He studied at London and Oxford. He is best known for the development of Occam’s razor, but he had many other important theories, causing him to be regarded as, along with St. Thomas Aquinas and John Duns Scotus, as one of the most significant medieval philosophers.
Some conservatives such as Richard M. Weaver, Rod Dreher, and Peter Kreeft have criticized William of Ockham, noting that his idea of nominalism helped set the stage for rationalism, scientism, and secularism as well as even the downfall of the West through denying the existence of universal natures.
He is perhaps best known for Occam's Razor , a philosophical concept which states that the most simple explanation is always more likely to be the true explanation unless evidence demands a more complicated one. This is vital in the philosophy of science. Ockham is also known for arguing that natural theology (that is, arguing for God's existence using logic) is completely futile as a subject. Nevertheless, Ockham's entire philosophical system is essentially based on God as a necessary, all-powerful and all-knowing being by whom all possibilities have their grounding. Ockham is also well known for his espousal of a view called nominalism, the view that abstract platonic objects and/or essences (i.e. numbers, sets, laws of logic, colors, etc.) do not exist but are just made-up conceptions in the human mind.
He most likely died a victim of the first wave of Black Death in Europe.