Voltaire vs Rousseau: Two Enlightenments, Two Philosophies

“I have received, Sir, your new book against the human race. Never has so much wit been employed to make us stupid; reading your work makes one want to walk on all fours.”

This letter from Voltaire to Rousseau, in 1755, perfectly summarizes their relationship: a mixture of reluctant admiration and scathing contempt. These two men, the greatest philosophers of the French Enlightenment, hated each other with a passion matched only by their genius.

Voltaire (1694-1778) and Jean-Jacques Rousseau (1712-1778) lived in the same era, frequented the same salons, fought the same enemies. But they represented two radically opposed visions of man and society. Their quarrel wasn’t personal - it was a conflict of ideas that continues to shape our world.

Two Lives, Two Destinies

Voltaire: The Prince of the Enlightenment

François-Marie Arouet - he only took the name Voltaire at 24 - was born in 1694 into a wealthy Parisian bourgeois family. His father was a notary, his family well-established. He grew up in comfort, attended the best Jesuit colleges, and showed exceptional literary talent from an early age.

At 20, he was already famous as a poet and playwright. At 30, his tragedies rivaled those of Corneille and Racine. At 40, he was the most famous writer in Europe. Kings and queens competed for his presence, publishers fought over his manuscripts, his witticisms circulated through the salons.

But this glory came at a price. Voltaire was imprisoned in the Bastille twice for his satirical writings, exiled to England for three years, driven from Paris multiple times. He learned early that the powerful don’t like being mocked - but he could never help himself.

His stay in England (1726-1729) was decisive. There he discovered a freer, more tolerant society, where a Newton could be buried in Westminster and a Locke respected as a philosopher. He returned with the Philosophical Letters, a praise of England that was also a devastating critique of France. The book was burned by the executioner.

Voltaire spent his life navigating between glory and disgrace, between royal courts and border refuges. He eventually settled in Ferney, near Geneva, from where he could flee to Switzerland if the French authorities threatened him. From there, he flooded Europe with pamphlets, tragedies, philosophical tales, letters - a staggering output filling dozens of volumes.

Rousseau: The Tormented Outsider

Jean-Jacques Rousseau was born in 1712 in Geneva, into a family of Protestant watchmakers. His mother died giving birth to him - a guilt he carried his whole life. His father, unstable and violent, abandoned him at 10. Rousseau was raised by uncles, apprenticed to a brutal engraver, and ran away at 16.

His youth was a wandering. He lived off odd jobs, converted to Catholicism (then returned to Protestantism), became the protégé and lover of Madame de Warens, an older woman who introduced him to culture. He taught himself music, read everything he could find, and developed a heightened sensitivity that never left him.

At 30, Rousseau arrived in Paris with no money, no connections, no degrees. He survived by copying music, giving lessons, writing articles. He frequented the philosophers - Diderot, d’Alembert, Condillac - but never really felt like one of them. He was too poor, too rough around the edges, too emotional.

His fame came suddenly, in 1750. The Academy of Dijon had proposed a competition topic: “Has the progress of sciences and arts contributed to corrupting or purifying morals?” All the philosophers would obviously answer yes, progress is good. Rousseau answered no - and won the prize.

This Discourse on the Sciences and Arts caused a scandal. Rousseau argued that civilization had corrupted us, that natural man was good, that progress was an illusion. It was a frontal attack on everything the Enlightenment stood for. And it was the beginning of his war with Voltaire.

Their Philosophies: Two Visions of Man

Voltaire: Progress Through Reason

Voltaire believed in progress. Humanity was advancing, slowly but surely, from barbarism toward civilization. Sciences discovered the laws of nature, philosophy dispelled superstitions, commerce softened morals. The future would be better than the past.

The engine of this progress was reason. For Voltaire, humanity’s ills came from ignorance, fanaticism, superstition. The solution was education, spreading the Enlightenment, fighting prejudices. “Crush the infamous thing!” he repeated - the infamous thing being religious intolerance.

Voltaire wasn’t naive. He knew evil existed, that injustice was everywhere, that the powerful crushed the weak. Candide, his masterpiece, is a fierce satire of smug optimism. But he believed things could be improved, step by step, reform after reform.

His philosophy was practical, concrete. He didn’t build abstract systems - he fought specific injustices. The Calas affair (a Protestant unjustly executed), the affair of the Chevalier de La Barre (a young man tortured for blasphemy), the Sirven affair… Voltaire fought to rehabilitate victims of intolerance, using his pen as a weapon.

“We must cultivate our garden,” Candide concludes. For Voltaire, that meant: stop metaphysical speculations, work to improve our world here and now.

Rousseau: Return to Nature

Rousseau believed exactly the opposite. Man is born good, he said, it’s society that corrupts him. The “noble savage” living in the state of nature was free, happy, virtuous. Civilization had chained him, made him unhappy, vicious.

“Man is born free, and everywhere he is in chains.” This famous sentence from The Social Contract summarizes his thought. Social institutions - property, laws, governments - weren’t progress, but instruments of oppression. They had created inequality, servitude, unhappiness.

Rousseau’s solution wasn’t to return to the state of nature - he knew that was impossible. It was to rebuild society on new foundations, conforming to human nature. The Social Contract proposed a model: a democracy where the “general will” would guide decisions, where each citizen would be both sovereign and subject.

Rousseau also believed in education, but a different education from Voltaire’s. In Emile, he proposed a “natural” pedagogy: let the child develop at their own pace, in contact with nature, away from books and artificial constraints. Education should form men, not scholars.

His philosophy was sentimental as much as intellectual. Reason alone wasn’t enough - one had to listen to the heart, conscience, inner feeling. “Conscience! Conscience! Divine instinct, immortal and celestial voice…” Rousseau trusted moral intuition more than abstract reasoning.

Their Quarrel: Mutual Hatred

Origins of the Conflict

At first, they admired each other. Voltaire praised Rousseau’s first Discourse, even though he disagreed. Rousseau admired Voltaire’s tragedies. They corresponded politely.

But tensions soon appeared. Voltaire mocked Rousseau’s thesis about corruption by civilization. Rousseau criticized Voltaire’s luxurious lifestyle. Their temperaments were incompatible: one was an aristocrat of the mind, the other a plebeian of feeling.

The break was finalized after the Lisbon earthquake (1755). Voltaire wrote a despairing poem about the evil and injustice of the world. Rousseau replied: the Lisboners’ misfortune came from their choice to live packed together in a big city, far from nature. Voltaire was outraged.

Then came the Geneva affairs. Voltaire had settled near the city and was staging plays there - which was forbidden by the Calvinist authorities. He campaigned to lift this ban. Rousseau, in his Letter on the Theatre, defended the ban: theater corrupted morals. Voltaire saw it as a personal betrayal.

Escalation

From then on, the war was total. Voltaire attacked Rousseau in anonymous pamphlets, mocking his poverty, his inconsistencies, his paranoia. He revealed that Rousseau had abandoned his five children to public welfare - a secret Rousseau had jealously guarded.

Rousseau counterattacked in the Confessions, a merciless self-portrait that also settles scores with his enemies. He describes Voltaire as a man “whose talents only serve to harm,” a hypocrite who preached virtue while living in luxury.

The two camps clashed. The “philosophers” supported Voltaire. The emerging romantics preferred Rousseau. Enlightenment Europe divided between reason and sentiment, progress and nature, civilization and authenticity.

The quarrel lasted until their deaths, the same year: 1778. They never reconciled.

Their Legacies: Two Modernities

Voltaire: Liberalism

Voltaire’s legacy is political liberalism. Separation of church and state, freedom of expression, religious tolerance, individual rights - all of this comes from Voltarian battles.

His fight against intolerance remains urgently relevant. Every time a fanatic kills in the name of their faith, every time a government censors the press, every time an individual is persecuted for their opinions, we think of Voltaire. “I disapprove of what you say, but I will defend to the death your right to say it” - this phrase (which he probably never said, but which summarizes his thought) has become the credo of liberalism.

Voltaire also bequeathed a style: irony, sarcasm, the killing bon mot. His wit continues to inspire satirists, polemicists, all who use laughter as a weapon against obscurantism.

But Voltaire also has his limits. He was elitist, contemptuous of the common people. He didn’t really believe in democracy - he preferred the “enlightened despotism” of Catherine of Russia or Frederick of Prussia. And his antisemitism (common at the time, but virulent in him) remains a stain on his legacy.

Rousseau: Democracy and Romanticism

Rousseau’s legacy is twofold: political and cultural.

Politically, Rousseau is the father of modern democracy. The Social Contract inspired the revolutionaries of 1789, the Declaration of the Rights of Man, republican constitutions. The idea that sovereignty belongs to the people, that government derives its legitimacy from the consent of the governed, that the general will must prevail - all of this comes from Rousseau.

But this influence is ambiguous. Robespierre invoked Rousseau when sending “enemies of the people” to the guillotine. The “general will” can become a tyranny of the majority. Rousseau’s critics see him as the ancestor of modern totalitarianisms - an exaggerated accusation, but not without foundation.

Culturally, Rousseau is the father of romanticism. His cult of nature, his valorization of feeling, his attention to childhood, his exploration of interiority - all of this announces the 19th century. The Confessions invented modern autobiography. The New Heloise launched the sentimental novel. Emile revolutionized pedagogy.

Rousseau also invented a posture: that of the marginal intellectual, misunderstood, persecuted, but bearer of a truth that society refuses to hear. This figure of the “cursed genius” runs through all of romanticism and continues to influence our imagination.

What They Teach Us Today

A Still-Living Debate

The Voltaire-Rousseau quarrel isn’t over. It continues in other forms, with other words.

Are you Voltairian or Rousseauist? Do you believe in progress or think we’ve lost something along the way? Do you trust reason or feeling? Do you prefer individual freedom or collective equality? These questions still divide our societies.

Liberals are Voltaire’s heirs: they believe in the market, individual freedom, progress through innovation. Environmentalists are often Rousseauist: they criticize industrial civilization, advocate a return to more “natural” ways of life, value community over individualism.

Even the debate about social media has Voltairian and Rousseauist overtones. Proponents of total freedom of expression invoke Voltaire. Those who want to regulate hate speech invoke Rousseau’s “general will.”

Two Complementary Truths?

Perhaps Voltaire and Rousseau were both right - and both wrong.

Voltaire was right to believe in progress. We live longer, in better health, with more freedoms than our ancestors. The Enlightenment brought modern medicine, human rights, the abolition of slavery.

But Rousseau was right to warn us. Progress has also created pollution, weapons of mass destruction, the alienation of modern work. We’ve gained comfort, but have we gained happiness?

Voltaire was right to defend reason against fanaticism. But Rousseau was right to remind us that man is not only reason - he is also emotion, intuition, conscience.

Perhaps we need both: Voltairian clarity to fight obscurantism, and Rousseauist sensitivity to not forget our humanity.

Conclusion: Two Enlightenments, One Humanity

Voltaire and Rousseau hated each other, but they fought the same fight: that of human freedom against the tyrannies of their time. They used different weapons - one reason, the other feeling - but they aimed at the same enemy: the oppression of man by man.

Their quarrel was also a conversation. By confronting each other, they forced each other to clarify their thoughts, respond to objections, go further. Enlightenment philosophy was born from this contradictory dialogue as much as from their individual works.

Today, we need both voices. We need Voltaire to remind us that reason is our best tool against ignorance and fanaticism. We need Rousseau to remind us that progress is not an end in itself, that it must serve human flourishing.

They died the same year, 1778, weeks apart. Eleven years later, the French Revolution broke out - a revolution that claimed both. The revolutionaries quoted Voltaire against the Church, Rousseau against the monarchy. The modern world was born from their double legacy.

This double legacy is still ours. Every time we debate freedom and equality, reason and emotion, progress and nature, we continue the conversation that Voltaire and Rousseau started more than two centuries ago. They taught us to think - and to never stop questioning.