All Thinkers

Voltaire

Voltaire was a French writer, philosopher, and campaigner who became the most famous voice of the European Enlightenment. His real name was François-Marie Arouet. He was born in Paris in 1694 to a middle-class family. As a young man, he wrote sharp poems and plays that mocked powerful people. Twice he was put in the Bastille prison for his words. He took the pen name 'Voltaire' around 1718. In his twenties he spent two years in exile in England. He admired the freer politics, the religious tolerance, and the science of Newton. Back in France, he spent his life writing across many forms: tragedies, histories, poems, novels, scientific essays, philosophical books, and thousands of letters. He wrote so much that his collected works fill more than 70 large volumes. He was always in trouble with the French government and the Catholic Church. To stay safe, he moved often. He spent years at the court of King Frederick the Great of Prussia, then in Switzerland, then in his own large estate at Ferney near the Swiss border. From Ferney, in his sixties and seventies, he became Europe's most famous writer. He defended people wrongly accused by the courts. He campaigned against torture, religious persecution, and superstition. He died in Paris in 1778, at the age of 83, treated like a hero by huge crowds. Eleven years later, his ideas helped fuel the French Revolution.

Origin
France
Lifespan
1694-1778
Era
Enlightenment / 18th-century Europe
Subjects
Enlightenment French Literature Philosophy Human Rights Religion
Why They Matter

Voltaire matters for three reasons. First, he was the public face of the Enlightenment, the great eighteenth-century movement for reason, science, and human freedom. He did not invent its main ideas, but he made them famous across Europe. He used wit, satire, and clear prose to attack superstition, intolerance, and unjust government. Educated people from Lisbon to Saint Petersburg read him.

Second, he turned writing into a tool for justice. When poor or unpopular people were tortured and killed by the courts on weak evidence, he campaigned for them. He wrote pamphlets, letters, and books defending Jean Calas, Pierre-Paul Sirven, and others. Through public pressure, he sometimes won. This was new: a writer using fame to fight unjust verdicts. It set a model for later public intellectuals like Émile Zola.

Third, he is one of the great prose stylists of any language. His short novel Candide is still read everywhere as a model of clear, fast, savagely funny writing. His campaigns for free speech, religious tolerance, and against legal cruelty set ideas that became central to modern democracies. Many things we now take for granted, including separation of church and state, were live and dangerous ideas when Voltaire fought for them.

Key Ideas
1
Who Was Voltaire?
2
Candide: The Joke Against Easy Optimism
3
Religious Tolerance
Key Quotations
"We must cultivate our garden."
— Candide, final sentence, 1759
This is the last line of Candide, and one of the most famous endings in European literature. After many disasters, Candide and his small group of friends have settled on a small farm. They give up grand theories about how good the world is. Instead they decide to do real, modest, useful work in their own corner of life. The line has been read in many ways. Some think it is a call to mind your own business. Others see it as a serious philosophy: change what you can, do useful work, do not get lost in vain speculation about cosmic meaning. For students, the line is a useful reminder. Big theories about the world are easy. Working honestly on real, small tasks is harder, and often more valuable.
"Common sense is not so common."
— Philosophical Dictionary, 1764, entry on common sense
Voltaire was good at making serious points sound like jokes. This line is one of his sharpest. We say someone has 'common sense' as if it were obvious and widespread. Voltaire points out that it is not. Most people, most of the time, believe strange and stupid things on no good evidence. Real careful thinking is rare. The line is a useful warning against assuming everyone agrees with what seems obvious to us. It is also a defence of education. If common sense were really common, we would not need to teach people to think carefully. For students, the line is a small example of Voltaire's method. He often took a familiar phrase, looked at it again, and showed that it did not mean what people thought it meant.
Using This Thinker in the Classroom
Creative Expression When teaching students about satire and wit
How to introduce
Read students a short passage from Candide, perhaps the section about the earthquake in Lisbon or Pangloss's lectures. Ask them what makes the writing funny. Voltaire used short sentences. He used absurd situations. He let stupid characters keep saying confident things while disasters happened around them. Discuss how satire works: by making something ridiculous, you can attack it more effectively than by attacking it directly. Voltaire is one of the great teachers of this technique. Students who write should know that humour can be as sharp as any other tool. Voltaire used jokes to take down whole systems of thought.
Critical Thinking When introducing students to questioning common beliefs
How to introduce
Voltaire is famous for the line 'common sense is not so common'. Use this with students to discuss the difference between what 'everyone says' and what is actually true. Ask them to think of beliefs they have heard from family, school, or social media that might not be as obvious as they sound. Voltaire's basic move was to take a familiar phrase or idea, examine it carefully, and show that it did not survive close inspection. This skill, careful examination of ordinary beliefs, is the start of critical thinking. It is also why Voltaire was always in trouble. People do not like having their assumptions questioned.
Ethical Thinking When discussing how individuals can fight injustice
How to introduce
Tell students about the Calas affair. A father was tortured and executed for a crime he did not commit, mainly because he was a Protestant in a Catholic city. Voltaire spent three years writing pamphlets, gathering evidence, and pushing the courts. The verdict was overturned. Discuss with students: what does this story teach about how individuals can fight unjust outcomes? Voltaire was already famous and had powerful friends, so he had advantages most people do not. But the basic method, public attention, careful evidence, and persistent pressure, has been used by campaigners ever since. Modern human rights work follows in this tradition.
Further Reading

For a first introduction, Theo Cuffe's Penguin translation of Candide (2005) is short, lively, and well-annotated.

Roger Pearson's Voltaire Almighty

A Life in Pursuit of Freedom (2005) is a readable biography.

Ian Davidson's Voltaire

A Life (2010) is also accessible. The BBC In Our Time podcast episodes on Voltaire and on Candide are good free starting points. Penguin and Oxford World's Classics both publish good selections of his shorter works.

Key Ideas
1
The Calas Affair
2
Voltaire and the Idea of Free Speech
3
Newton in French
Key Quotations
"If God did not exist, it would be necessary to invent him."
— Epistle to the Author of the Book of the Three Impostors, 1768
This is Voltaire's most quoted, and most misunderstood, line about religion. It is not a confession of belief, and it is not a sneer at faith. Voltaire was making a social argument. He thought belief in a watchful God helped keep ordinary people honest, especially people who would not be controlled by reason or laws alone. So even if God did not exist, society would have to invent the idea to keep itself in order. This is a deist's view, not an atheist's. Voltaire himself believed there was a creator. But he also believed religion was a useful social tool. For students, the line is a good example of how a single quote can be twisted. Voltaire is sometimes read as more anti-religious than he was, and sometimes as more religious. The line is sharper and stranger than either reading.
"Those who can make you believe absurdities can make you commit atrocities."
— Questions on the Miracles, 1765
This is one of Voltaire's most powerful lines. He had watched religious authorities convince ordinary people that other people deserved to be tortured and killed. The pattern was clear to him. First, get people to believe something absurd. Then, in the name of that belief, get them to do terrible things. The line is not only about religion. It applies to every system of belief that asks people to accept the unreasonable. Modern history has many examples in politics, ideology, and propaganda. For students, the line is a useful warning. The connection between false belief and cruel action is real. It runs through history. Asking 'is this true?' before acting is not just a private intellectual matter. It is a public moral one. Voltaire saw this clearly two and a half centuries ago.
Using This Thinker in the Classroom
Cultural Heritage and Identity When teaching students about the Enlightenment
How to introduce
Introduce Voltaire as the public face of the Enlightenment, the eighteenth-century European movement for reason, science, and human freedom. He did not invent the main ideas, but he made them famous through clear, witty writing that ordinary educated people could read. Discuss with students: what made the Enlightenment important? What did it get right? What blind spots did it have? Voltaire is a good case study. He campaigned for tolerance, defended unjust prisoners, and spread science. He also held antisemitic views and was sometimes condescending about non-European peoples. A great moral movement can have serious flaws. Honest study includes both.
Critical Thinking When teaching students to check sources
How to introduce
The most famous quote 'by Voltaire' was actually written about him by an English biographer in 1906. He never said 'I disapprove of what you say, but I will defend to the death your right to say it.' Discuss this with students as an example of how famous quotations get attached to famous people, often wrongly. Many quotes from Einstein, Mark Twain, Lincoln, and others are similarly misattributed. The lesson is general: when you find a striking quote, check who actually said it and where. The internet makes spreading false attributions easy. Careful sourcing is part of basic intellectual honesty. Voltaire would have approved of the lesson, even if he never quite said it.
Further Reading

For deeper reading, Nicholas Cronk's edition of Candide and Other Stories (Oxford, 2008) is well introduced and annotated. The Cambridge Companion to Voltaire, edited by Nicholas Cronk (2009), is a useful collection of essays by leading scholars. Voltaire's Treatise on Tolerance and his Philosophical Dictionary (both available in good Penguin and Oxford editions) show his campaigning and philosophical work. For Émilie du Châtelet, Judith Zinsser's biography Emilie du Châtelet: Daring Genius of the Enlightenment (2007) is excellent.

Key Ideas
1
Voltaire's Antisemitism
2
Deism, Not Atheism
3
The Trouble with Eurocentrism
Key Quotations
"I disapprove of what you say, but I will defend to the death your right to say it."
— Widely attributed to Voltaire, but actually written about him by Evelyn Beatrice Hall in The Friends of Voltaire, 1906
The most famous quotation 'by' Voltaire is not by Voltaire. The English writer Evelyn Beatrice Hall used it in 1906 to summarise his attitude. She did not claim he had said it; later readers turned her summary into a quote. The line, however, fairly captures what Voltaire stood for. He did fight for the freedom to publish ideas he did not share, including ideas he disliked. The misattribution is a useful case for students. Famous quotes are often not what they seem. Many lines attributed to historical figures were actually said by other people, or by them in different words, or never said at all. Checking the source matters. The popular Voltaire and the historical Voltaire are not always the same person.
"Doubt is not a pleasant condition, but certainty is absurd."
— Letter to Frederick William, Prince of Prussia, 28 November 1770
Voltaire understood the discomfort of doubt. We do not like not knowing. But he understood the greater absurdity of false certainty. To claim we definitely know what we cannot know is to invite mistakes, cruelty, and disaster. The line is a defence of intellectual humility, the careful awareness of how much we do not know. It is also a warning about confidence in religion, politics, science, and everyday life. People who are absolutely sure they are right are often the most dangerous. For advanced students, the line is a useful corrective to the desire for clear answers. Most of the most important questions remain open. Living well with uncertainty is a serious skill, harder than it looks, and worth practising. Voltaire spent his life trying.
Using This Thinker in the Classroom
Research Skills When teaching students about translation and the spread of knowledge
How to introduce
Newton's Principia was written in Latin in 1687. It was difficult and not widely read. The standard French translation, used by educated readers across Europe, was made by Émilie du Châtelet and finished in the 1740s. Voltaire, her partner, wrote a popular book explaining Newton's ideas. Discuss with students: how does knowledge actually spread between countries and languages? It takes translators, popularisers, and patient explainers. Many of these people, especially women, have been written out of the standard story. Du Châtelet's translation is still in use; Voltaire's book made the ideas famous. Both played essential roles. Translation is intellectual work in its own right, not a service to the 'real' work of the original author.
Ethical Thinking When discussing thinkers with mixed legacies
How to introduce
Voltaire campaigned bravely against religious persecution of Protestants. He also wrote ugly, prejudiced things about Jews. Both are real. Discuss with students: how should we hold both at once? It does not mean we cancel his good work. It also does not mean we dismiss his bad views as harmless. Honest engagement with historical figures requires looking at the whole picture. Voltaire is a particularly clear case because his great cause was tolerance. His failure to extend it equally to all groups is a serious limit on his moral achievement. The exercise is good practice for thinking about other complicated figures, in history and in the present. Heroes are usually also flawed people. We can admire and criticise the same person.
Common Misconceptions
Common misconception

Voltaire said 'I disapprove of what you say, but I will defend to the death your right to say it.'

What to teach instead

He did not. The line was written about him by the English biographer Evelyn Beatrice Hall in her 1906 book The Friends of Voltaire. She used it as a summary of his views, not as a quotation from him. Later readers turned the summary into a direct quote, and it has stuck ever since. The line does fairly describe what Voltaire fought for. He defended the freedom to publish ideas he disagreed with, and he fought censorship throughout his life. But the famous wording is Hall's, not his. This is one of the most widely repeated misattributions in the history of quotations.

Common misconception

Voltaire was an atheist who hated all religion.

What to teach instead

He was not an atheist. He was a deist, which means he believed in a creator God but rejected most of organised religion. He thought the order of nature pointed to an intelligent designer. What he attacked was church authority, miracles, religious persecution, and what he called superstition. He also famously argued that even if God did not exist, society would need to invent the idea to keep itself in order. This is a complicated, sometimes inconsistent position, but it is not atheism. Many Enlightenment figures held similar views, including Thomas Jefferson and Benjamin Franklin. Reading Voltaire as a flat anti-religious figure misses the more interesting position he actually held.

Common misconception

Voltaire stood for tolerance towards everyone.

What to teach instead

He did not. He campaigned bravely for Protestants, who were being persecuted in Catholic France. He defended individuals he believed had been unjustly accused. But his writings about Jewish people are full of prejudice, repeating old stereotypes about greed, superstition, and clannishness. Some scholars argue this was mainly aimed at Judaism as a religion, others that it was real ethnic prejudice. The debate is unresolved. What is clear is that Voltaire's tolerance was not consistent. This is a serious limit on his moral achievement, and honest engagement with him includes acknowledging it. He was a champion of justice for some and a producer of prejudice against others.

Common misconception

Candide is a cheerful comic novel.

What to teach instead

It is funny, but its mood is angry, not cheerful. Voltaire wrote it after the Lisbon earthquake of 1755 had killed tens of thousands of people. He was furious with thinkers who claimed everything happened for the best in this best of all possible worlds. The book exposes its hero to one disaster after another: war, rape, slavery, religious cruelty, natural catastrophe, and personal betrayal. The jokes are sharp because they are written against real human suffering. The famous final line, 'we must cultivate our garden', is not a happy ending but a tired, modest conclusion after grand theories have failed. Reading Candide as light entertainment misses why it has lasted. It is a serious moral protest, in the form of a fast and very funny short novel.

Intellectual Connections
In Dialogue With
Blaise Pascal
Voltaire wrote a long set of critical comments on Pascal's Pensées. He admired Pascal's prose but disagreed sharply with his religious pessimism. Pascal saw human beings as small, fallen, and in need of grace. Voltaire saw them as capable of progress through reason, science, and reform. Pascal vs. Voltaire is one of the great debates in French thought: a Christian sceptic of human progress against an Enlightenment defender of it. Reading them together gives students a strong sense of what was at stake in seventeenth and eighteenth-century French intellectual life.
In Dialogue With
Jean-Jacques Rousseau
Voltaire and Rousseau are the two most famous French Enlightenment writers, and they did not get on. Voltaire admired civilisation, science, and refined manners; Rousseau distrusted them and praised simpler, more natural ways of living. Voltaire defended the rich republic of letters; Rousseau defended ordinary people against intellectual elites. They wrote sharp things about each other for years. Reading them together shows that the Enlightenment was not one movement but a serious internal argument. Modern debates between progress and authenticity, between cosmopolitan and local values, often echo this older quarrel.
Complements
John Locke
Voltaire spent two years in exile in England and came back deeply impressed by English political culture. He admired Locke's ideas about religious toleration, limited government, and the human mind shaped by experience. He helped popularise these ideas in France through his Letters Concerning the English Nation. Locke gave Voltaire much of his philosophical framework. Voltaire then turned it into shorter, sharper, and more accessible writing. Reading them together shows how an academic philosopher and a public writer can work in partnership across borders, with the philosopher developing the ideas and the writer carrying them to a wider audience.
Complements
Montesquieu
Montesquieu and Voltaire were the two great French political thinkers of the early Enlightenment. Both spent time in England and admired its constitutional government. Both opposed absolute monarchy. Montesquieu worked on long, systematic political theory, especially in The Spirit of the Laws. Voltaire worked in shorter, more direct forms. Their projects were complementary. Montesquieu provided the institutional analysis; Voltaire provided the public campaigning. Together they helped lay the intellectual ground for the French Revolution and modern constitutional democracy. Reading them together gives students a fuller picture of how Enlightenment political thought actually worked.
Anticipates
George Orwell
Orwell, writing in twentieth-century Britain, took up Voltaire's project of using clear, plain prose to attack political cruelty and propaganda. Like Voltaire, Orwell wrote across many forms: essays, journalism, novels, satire. Like Voltaire, he saw clear writing as a moral duty. Orwell's Animal Farm, with its sharp short style and political bite, is a direct descendant of Candide. Both writers believed that ordinary readers deserved honest, accessible prose, and that powerful institutions deserved sceptical, witty attack. Reading them together shows a long line of writers who treated literature as a form of public service.
Complements
Confucius
Voltaire admired Confucian thought, which he knew from translations and Jesuit reports. He saw Confucius as a model of practical, this-worldly wisdom: an ethics built on social order and human relationships, without supernatural claims. Voltaire used Confucius partly as a real source of admiration, partly as a stick to beat European Christianity with. The picture he gave was sometimes idealised. But the willingness to take a non-European tradition seriously was unusual in his time. Reading them together shows both the genuine cross-cultural curiosity of the Enlightenment and its tendency to use foreign traditions for European purposes.
Further Reading

For research-level engagement, the standard scholarly edition is the ongoing Œuvres complètes de Voltaire from the Voltaire Foundation in Oxford, which has run since 1968 and is now nearly complete. René Pomeau's multi-volume Voltaire en son temps remains foundational in French. Adam Sutcliffe's Judaism and Enlightenment (2003) is essential for understanding Voltaire's antisemitism in context. The journal Studies on Voltaire and the Eighteenth Century publishes ongoing scholarship. For the Calas affair, David Bien's The Calas Affair (1960) remains the standard study in English.