William of Ockham (1285–1347) was an English philosopher who is known for: (1) his promotion of nominalism; (2) the creation of Ockham’s Razor; (3) his belief in voluntarism; and (4) his clashes with the established church and pope.
First, William of Ockham was a nominalist because he rejected the concept of universals in which there are independent metaphysical realities that objects in this world partake of. (For example, some believe that redness is a universal in which particular objects such as red apples and fire engines partake). Ockham, though, argued that universals were unnecessary and needed to be eliminated. Since most medieval philosophers of his era, including Thomas Aquinas, believed in universals, Ockham’s stance against universalism and for nominalism was significant.
Second, William was concerned that the disciplines of philosophy and theology were loaded with far too many unnecessary hypotheses. In an effort to deal with the needless speculations of his day, Ockham’s created a figurative “razor” in which all needless hypotheses were cut out. The doctrine of universals was one such concept that Ockham believed needed to be cut away from the study of philosophy.
Third, William promoted a form of voluntarism in which God is viewed as having absolute freedom to do whatever he wishes. According to Ockham, God’s acts are purely voluntary in that he did not have to act as he did. For example, God did not have to create the world or send his Son Jesus to earth to die. Also, God could have chosen another way to save mankind if he so desired. William also asserted that since God is perfect and infinite, he cannot be said to be bound by human reason which is imperfect and finite. According to William, faith and reason could not be reconciled. This approach led to the expansion of mysticism.
Fourth, William was known for his own life of poverty and the challenging of the luxurious lifestyle of medieval church including that of Pope John XXII. William upset Pope John so much that the pontiff declared belief in apostolic poverty to be heretical. William also riled the church with his declaration that the Bible was the only infallible authority in matters of faith. This idea would be picked up later by Martin Luther and others associated with the Protestant Reformation. In spite of his troubles with the established church of his day, William was reconciled with the Roman Catholic Church before his death.