Nominalism

The view that there are no universals, or no abstract objects; only particular things exist.

Also: nominalist, anti-realism about universals

What it means

Nominalism comes in two main forms. One denies universals: when two apples are both red, there is no single shared redness, only two red things. The other denies abstract objects such as numbers and sets. In the medieval debate, Roscelin held a strict version, Peter Abelard argued that only words are universal in the strict sense, and William of Ockham combined nominalism with empiricism. Modern versions explain similarity in different ways: through particular property instances called tropes, through resemblance, or through the predicates we apply. Nelson Goodman and W. V. O. Quine rejected classes as abstract entities. Critics, notably D. M. Armstrong, who mocked the barest version as 'ostrich' nominalism, defend universals instead.

The questions it belongs to

• 1.1.2 Universals and ParticularsA tomato and a fire engine are both red. Is there something they share?
• 1.1.4 Abstract ObjectsDoes the number seven exist?

Thinkers

• Peter Abelard
• William of Ockham
• Nelson Goodman
• W. V. O. Quine

Traditions

• Medieval Christian
• Modern European
• Analytic

To read

• Ethics, or Know Yourself (Scito te ipsum) — Peter Abelard
• Fact, Fiction, and Forecast — Nelson Goodman
• From a Logical Point of View — W. V. O. Quine

Sources and further reading

• Nominalism in Metaphysics (Stanford Encyclopedia of Philosophy)
• Nominalism (Britannica)
• The Medieval Problem of Universals (Stanford Encyclopedia of Philosophy)

Written by the Coordinates of Thought editors and checked against the sources above on 29 October 2026. Not peer-reviewed. How we write and check.

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