Voltaire IQ

Voltaire's IQ is estimated at 170 to 190. Cox's 1926 study gave him a corrected 190, the same as Newton; he was never tested.

Voltaire's IQ is 170+. What's yours?

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Portrait of Voltaire

Key facts

Estimated IQ
IQ 170+
Range
IQ 170 to IQ 190
Known for
Candide, the Enlightenment
Lived
Writer & Philosopher, 1694–1778
Basis
Cox 1926 historiometric estimate
Confidence
Low. Voltaire died in 1778. No test exists; the figure below is from a 1926 study of biographies.

Voltaire's 190 is Cox's 1926 corrected estimate. His speed, wit and output are well documented; the number is an old-scale estimate, not a result.

What was Voltaire's IQ?

Voltaire never took an IQ test. Catharine Cox's 1926 study gave him a corrected estimate of 190, equal to Newton and Laplace. Adjusted for the Flynn effect that falls to about 170, so LifeScore uses a range of 170 to 190 for his estimated IQ.

How smart was Voltaire?

Very, on the record. He wrote poetry, plays, history, philosophy and more than 20,000 letters, explained Newton's physics to French readers, and exposed legal injustice in cases such as the Calas affair. He even spotted a flaw in a French state lottery and made a fortune from it.

Voltaire's key achievements

  1. 01

    Candide

    His 1759 satire demolished easy optimism and is still one of the most read books of the Enlightenment.
  2. 02

    Bringing Newton to France

    With Émilie du Châtelet he explained Newtonian physics to French readers in the 1730s.
  3. 03

    Letters on the English

    His 1733 book used English institutions to criticise French absolutism and religious intolerance.
  4. 04

    The Calas campaign

    He campaigned for years to clear Jean Calas, a Protestant executed on false charges, and won.

How Voltaire thought

Voltaire thought fast and wrote faster. His method was to take a comfortable belief, state it clearly and then show its absurd consequences. The result was writing that entertained and argued at the same time.

The evidence behind the estimate

An estimate built from the historical record, not a recovered test score.

What supports it

  • Cox's 1926 study gave Voltaire a corrected estimate of 190, about 170 after a Flynn-effect adjustment.
  • His surviving correspondence runs to more than 20,000 letters.
  • He helped bring Newton's physics to French readers in the 1730s, working with Émilie du Châtelet.

What it cannot prove

  • Voltaire curated his own legend, and biographies repeat his best lines.
  • Literary fame and wit are not direct measures of reasoning.
  • Cox's scale runs higher than modern deviation IQ.

Voltaire compared with Goethe, Franklin, Frederick

FigureEstimateRange
Voltaire170+170–190
Johann Wolfgang von Goethe190+190–210
Benjamin Franklin150+140–160
Frederick the Great140+130–150

Psychological profile

Voltaire's IQ is represented here by a retrospective estimate of 170+, not a verified test result. Voltaire is best known for exceptional wit. The useful question is what the surviving evidence shows, not whether a precise modern score can be recovered.

Quick, combative and prolific. Used wit as a weapon against injustice.

The dominant archetype here is The Rebel. This archetype shapes decision patterns: what feels natural, what creates friction, and what blind spots tend to emerge.

Estimated IQ is 170+. This is a rough estimate based on documented accomplishments and contemporary accounts, not a literal measurement.

Key traits

  1. Wit

    He was imprisoned in the Bastille in his early twenties for satirical verses.

  2. Productivity

    He corresponded with Frederick the Great for decades and edited his Anti-Machiavel.

  3. Skepticism

    He reportedly drank dozens of cups of coffee a day.

One thing most people do not know

Voltaire and the mathematician La Condamine made a fortune by buying up tickets in a badly designed French state lottery in 1729.

Voltaire: common questions

Was Voltaire a genius?

Voltaire's record supports exceptional achievement, but "genius" is not established by an unverified IQ number. Their The Rebel archetype, combined with Wit and Productivity, is a more useful interpretation of their output.

What personality type was Voltaire?

Voltaire fits the The Rebel archetype. Key traits include Wit, Productivity, and Skepticism. This profile helps explain both their strengths and their documented failure modes.

What can we learn from Voltaire?

Voltaire's profile teaches that extreme strengths create extreme trade-offs. Their Wit and Productivity enabled success but also created recurring friction.

Voltaire's IQ is 170+. What's yours?

Voltaire's estimate comes from the historical record. Yours can come from a real test: 25 visual reasoning questions.

Take the IQ test

25 questions · about 12 minutes

Sources

  1. Voltaire, Stanford Encyclopedia of Philosophy. Scholarly account of his philosophy, Newtonianism and campaigns.
  2. The Early Mental Traits of Three Hundred Geniuses (Cox, 1926), Stanford University Press, via Internet Archive. The original historiometric study. Cox rated 301 eminent people born 1450 to 1850 from records of their childhood and youth.
  3. Cox's IQ estimates of 301 eminent geniuses, IQ Comparison Site. Secondary tabulation of Cox's corrected estimates, with a version adjusted by about 22 points for the Flynn effect.
  4. Cox, C. M. (1926). The Early Mental Traits of Three Hundred Geniuses. Stanford University Press.
  5. Simonton, D. K. (2009). Genius 101. Springer.
  6. Cattell, R. B. (1971). Abilities: Their Structure, Growth, and Action. Houghton Mifflin.
  7. Portrait: Nicolas de Largillière · CC0 · Wikimedia Commons

Last reviewed September 2026. How we estimate historical IQ