William Ockham

c. 1285-c. 1349

William Ockham, known as William of Ockham (or Occam), had a significant effect on the decline of medieval Scholasticism, the separation of church and state, and the eventual rise of scientific thinking. Although his writing and teaching led to his excommunication, the importance of his thought was later recognized and he is regarded as a major philosopher of the Church. He is best known for his use of the Law of Economy, known as Ockham's Razor.

Ockham was trained in logic and, at an early age, became a member of the Franciscan Order. He studied at Merton College of Oxford University and taught there from 1309-1319. His ideas were controversial, and he left without his master's degree. He taught in Paris from 1320-23 and published a number of writings opposing the Church's involvement in secular political activities, thereby angering the Papal Court, which was in residence in Avignon, France, at that time. He was also denounced by the former Chancellor of Oxford for heretical teachings. In 1324, he was summoned to Avignon by Pope John XXII for investigation of heresy and remained under house arrest there until he escaped to Germany and the court of Holy Roman Emperor Louis IV in 1328. He continued to support Louis's opposition to the Pope's involvement in the secular affairs of the empire, even accusing the Pope of heresy, and was excommunicated. He died in Germany, apparently of the plague that was sweeping Europe.

Ockham advocated a major reform in medieval philosophy. He opposed much of the Aristotelian system of the Scholastics on the basis that it was excessively deterministic and did not allow enough freedom to either God or humans. Although he had great personal faith in God and supported the Church's rule in all matters of the spirit, he also had faith in the human use of logic. In opposition to the prevailing philosophical and religious thought of the day—principally the Scholastic schools of Thomas Aquinas and John Scotus—Ockham showed by the use of logic that many basic religious beliefs, even the existence of God, could not be proved by philosophical reasoning. He contended that these religious beliefs could be based only on divine revelation (in which he firmly believed). He also held that the human mind could never be certain of many, if not most, philosophical propositions, but must rely on logical arguments of the probability of their truth. He is thus called a skeptic and a probabilist. He is also called a nominalist or terminist because he denied that the way we know something (i.e. the forms of knowledge) coincide exactly with the actual things (i.e the forms of being).

Ockham not only sought to reform Scholasticism through his philosophical ideas, he also believed that Scholasticism had become much too complex with its convoluted subtle arguments and needed to be simplified. He used as a basic principle the law of economy or parsimony: Pluralitas non est ponenda sine necessitate, or, it is better, in explaining something, to use as few assumptions as possible. This law had been stated earlier by Durand de Saint-Pourcain, but because of Ockham's extensive use of it as a basic principle underlying all phenomena, it is now known as Ockham's Razor. Since Ockham's day, this rule has become one of the fundamental principles of science. Whenever there are several competing explanations or theories, the simplest one, the one that requires the fewest assumptions, is selected as the correct choice.

In addition to his Razor, Ockham's skepticism, his separation of religious and secular authority, and his probabilistic and nominalistic philosophy have significantly influenced the eventual development of modern science.

J. WILLIAM MONCRIEF