Voltaire IQ
Writer & Philosopher · 1694–1778
Quick Answer
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 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.
- Estimated IQ
- 170+
- Range
- 170–190
- Known for
- Candide, the Enlightenment
- Basis
- Cox 1926 historiometric estimate
Evidence status: Low confidence. Voltaire died in 1778. No test exists; the figure below is from a 1926 study of biographies. Historical achievement cannot be converted into a precise modern test result. This page separates documented evidence from interpretation.
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.
Where does the 190 figure come from?
The 190 is Catharine Cox's corrected estimate from her 1926 study of 301 eminent people born between 1450 and 1850. She rated each person from biographical records of what they could do as a child and young adult, then corrected for gaps in the record.
Cox's numbers sit on an old ratio-IQ scale. One secondary tabulation subtracts about 22 points for the Flynn effect, which puts Voltaire near 170.
LifeScore lists 170+, and the working range of 170 to 190 spans both figures. None of them is a test result.
Voltaire's key achievements
Candide
His 1759 satire demolished easy optimism and is still one of the most read books of the Enlightenment.
Bringing Newton to France
With Émilie du Châtelet he explained Newtonian physics to French readers in the 1730s.
Letters on the English
His 1733 book used English institutions to criticise French absolutism and religious intolerance.
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.
Evidence behind the Voltaire IQ estimate
The estimate is a structured interpretation of the record, not a recovered test score. These are the strongest signals and the reasons for caution.
Evidence considered
- 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 the estimate 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 vs Goethe, Franklin, Frederick
How Voltaire's estimate compares with related figures. Every number here is an estimate, and the basis differs from person to person.
| Figure | Estimate | Range |
|---|---|---|
| Voltaire | 170+ | 170–190 |
| Johann Wolfgang von Goethe | 190+ | 190–210 |
| Benjamin Franklin | 150+ | 140–160 |
| Frederick the Great | 140+ | 130–150 |
Take the Voltaire IQ test
Voltaire's estimate is 170+. Our Einstein IQ test is a short visual reasoning challenge. See which side of that number you land on.
Take the Voltaire IQ testVoltaire'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.
Psychological Profile
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 Behavioral Traits
He was imprisoned in the Bastille in his early twenties for satirical verses.
He corresponded with Frederick the Great for decades and edited his Anti-Machiavel.
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.
Sources for this estimate
Follow the evidence yourself. These sources document the achievements and context used here; none is presented as a standardized IQ report.
- VoltaireStanford Encyclopedia of Philosophy
Scholarly account of his philosophy, Newtonianism and campaigns.
- 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.
- Cox's IQ estimates of 301 eminent geniusesIQ Comparison Site
Secondary tabulation of Cox's corrected estimates, with a version adjusted by about 22 points for the Flynn effect.
What do these scores mean?
See what an IQ of 170, 190 means in percentiles, then browse every famous estimate in one table.
Related famous IQs
- Johann Wolfgang von Goethe IQ190+
- Benjamin Franklin IQ150+
- Frederick the Great IQ140+
- Sigmund Freud IQ140+
- Socrates IQ155+
- Confucius IQ145+
- Plato IQ160+
- Aristotle IQ160+
Same Archetype: The Rebel
Explore psychological profiles of contemporary figures analyzed with similar methods.
Browse All ProfilesSigns of High IQ
Traits often discussed alongside high measured IQ:
Voltaire: People Also Ask
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.
References & Sources
Cox, C. M. (1926). The Early Mental Traits of Three Hundred Geniuses. Stanford University Press.
Simonton, D. K. (2009). Genius 101. Springer Publishing Company.
Cattell, R. B. (1971). Abilities: Their Structure, Growth, and Action. Houghton Mifflin.