Occam’s razor

Table of Contents

Introduction & Top Questions References & Edit History Quick Facts & Related Topics

Images

Occam’s razor

Q: What is Occam’s razor?

Occam’s razor is a principle of theory construction or evaluation according to which, other things equal, explanations that posit fewer entities, or fewer kinds of entities, are to be preferred to explanations that posit more. It is sometimes misleadingly characterized as a general recommendation of simpler explanations over more complex ones.

Q: Who created Occam’s razor?

Occam’s razor is credited to William of Ockham , a Franciscan theologian and philosopher who lived during the late 13th to mid-14th century, though he was not the first to propose it. ( Durandus of Saint-Pourçain and John Duns Scotus were among those who articulated the idea earlier.) Ockham’s original statement of the principle, in its most common form, is Pluralitas non est ponenda sine necessitate , which translates from Latin to “Plurality should not be posited without necessity.”

Q: What is an example of Occam’s razor?

In evolutionary biology, the method of maximum parsimony relies on the logic of Occam’s razor, seeking to construct an evolutionary tree that requires the fewest phylogenetic changes along all branches. However, reliance on this method is controversial, because it may oversimplify evolution, which does not always take a minimum path.

Q: Is Occam’s razor valid?

The validity of Occam’s razor has long been debated. Critics of the principle argue that it prioritizes simplicity over accuracy and that, since one cannot absolutely define “simplicity,” it cannot serve as a sure basis of comparison. They cite as an example the competing theories of creationism and evolution , in which relative “simplicity” depends on temporal and cultural context. Learn more.

philosophy

Also known as: Ockham’s razor, law of economy, law of parsimony

Written by Brian Duignan

Fact-checked by The Editors of Encyclopaedia Britannica

Last Updated: Oct 21, 2024 • Article History

Also spelled:: Ockham’s razor

Also called:: law of economy or law of parsimony

Key People:: William of Ockham

Related Topics:: ontology

See all related content

What is Occam’s razor?

Who created Occam’s razor?

What is an example of Occam’s razor?

Is Occam’s razor valid?

Occam’s razor, principle stated by the Scholastic philosopher William of Ockham (1285–1347/49) that pluralitas non est ponenda sine necessitate, “plurality should not be posited without necessity.” The principle gives precedence to simplicity: of two competing theories, the simpler explanation of an entity is to be preferred. The principle is also expressed as “Entities are not to be multiplied beyond necessity.”

The principle was, in fact, invoked before Ockham by Durandus of Saint-Pourçain, a French Dominican theologian and philosopher of dubious orthodoxy, who used it to explain that abstraction is the apprehension of some real entity, such as an Aristotelian cognitive species, an active intellect, or a disposition, all of which he spurned as unnecessary. Likewise, in science, Nicole d’Oresme, a 14th-century French physicist, invoked the law of economy, as did Galileo later, in defending the simplest hypothesis of the heavens. Other later scientists stated similar simplifying laws and principles.

Ockham, however, mentioned the principle so frequently and employed it so sharply that it was called “Occam’s razor” (also spelled Ockham’s razor). He used it, for instance, to dispense with relations, which he held to be nothing distinct from their foundation in things; with efficient causality, which he tended to view merely as regular succession; with motion, which is merely the reappearance of a thing in a different place; with psychological powers distinct for each mode of sense; and with the presence of ideas in the mind of the Creator, which are merely the creatures themselves.

William of Ockham, circa 1280 - 10.4.1349, English theologist and philosopher, portrait, later portrayal,