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Thinkers

William of Ockham

Scholastic · Europe · 1287 to 1347

English friar who held that only individual things exist. He said an explanation should not add more things than it needs.

What it is

William of Ockham was an English Franciscan philosopher of the fourteenth century, known for nominalism, for the principle of economy called Ockham's Razor, and for his part in the dispute over Franciscan poverty. He is counted among the most prominent figures of late medieval philosophy, together with Thomas Aquinas and John Duns Scotus.

He joined the Franciscan order and studied theology at Oxford, but never completed the degree. His views drew charges of heresy, and he was called to Avignon to answer them. He also became involved in a dispute with Pope John XXII over the idea of apostolic poverty, and he found refuge at the court of Louis of Bavaria, a would-be emperor, in Munich. His dates are uncertain: about 1287 to 1347 by one reckoning, and about 1280 to 1349 by another.

The main ideas

  • Nominalism. In metaphysics he held that only individual things exist and that universals, such as redness or humanity, are not things in their own right. They are concepts formed in our minds.
  • The Razor. The principle named Ockham's Razor is used to eliminate unnecessary entities from explanations.
  • Knowing by direct acquaintance. He described intuitive cognition, which can be thought of as perception, as the way we know individual things, without the help of innate ideas.
  • A language of thought. He held that there is a mental language underlying spoken language.
  • Logic. His major work in logic is the Summa Logicae.
  • The Sentences. Like other theologians of his time, he wrote a commentary on the Sentences of Peter Lombard, the standard theological textbook.

What it looks like in practice

Picture two explanations for why the house is cold. One says the heating is off. The other says the heating is off, and a second invisible cause is also at work. The Razor does not say the second must be false. It says that without a reason to add the extra cause, the simpler explanation is the one to prefer. This is an illustration of the principle, not an example from his books.

Books and moments

  • Summa Logicae is his major work in logic.
  • Commentary on the Sentences was a standard requirement for theologians.
  • The summons to Avignon began his long conflict with the papacy.
  • The court of Louis of Bavaria in Munich gave him a safe home.

Questions and criticism

  • Do universals exist? His nominalism sets him against thinkers who held that general kinds are real. It is fair to ask what makes things alike, if not a shared kind.
  • The great opponent of Aquinas? He has been cast as the outstanding opponent of Aquinas, though Aquinas had many other critics. It is fair to ask how far the story of a clash of two systems is true.
  • Is simpler better? The Razor is a rule of method, not a proof. It is fair to ask when the simpler explanation is also the true one.

Close neighbours

The page on Aquinas covers the thinker he is most often set against.

Written by epchē in our own words, and checked against independent sources on 9 October 2026. The sources are listed below.

Philosophies they belong to or are close to

Who they connect to

Influenced

  • Thomas Hobbes · Hobbes' view that general terms are only names echoes the nominalism of Ockham. (scholars disagree about this link)

Influenced by

  • John Duns Scotus · Ockham took up Scotus' questions and often argued against his answers.

Reacted against

  • John Duns Scotus · Ockham rejected Scotus' common natures and held that only individual things exist.

Other Scholastic thinkers

Sources we used

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