François-Marie Arouet (1694 - 1778), known by his nom de plume Voltaire was a French Enlightenment writer, historian and philosopher famous for his wit, his criticism of Christianity —especially the Roman Catholic Church - as well as his advocacy of freedom of speech, freedom of religion and the separation of church and state.

Voltaire was a versatile and prolific writer, producing works in almost every literary form, including plays, poems, novels, essays, histories, and scientific expositions. He wrote more than 20,000 letters and 2,000 books and pamphlets. He was one of the first authors to become renowned and commercially successful internationally. He was an outspoken advocate of civil liberties , and was at constant risk from the strict censorship laws of the Catholic French monarchy. His polemics witheringly satirised intolerance, religious dogma, and the French institutions of his day.

10 Things You Should Know About Voltaire

On the anniversary of Voltaire’s birth, learn 10 things you may not know about one of the 18th century’s most quotable and controversial thinkers.

1. The origins of his famous pen name are unclear.
Voltaire had a strained relationship with his father, who discouraged his literary aspirations and tried to force him into a legal career. Possibly to show his rejection of his father’s values, he dropped his family name and adopted the nom de plume “Voltaire” upon completing his first play in 1718. Voltaire never explained the meaning of his pen name, so scholars can only speculate on its origins. The most popular theory maintains the name is an anagram of a certain Latinized spelling of “Arouet,” but others have claimed it was a reference to the name of a family chateau or a nod to the nickname “volontaire” (volunteer), which Voltaire may have been given as a sarcastic reference to his stubbornness.

2. He was imprisoned in the Bastille for nearly a year.
Voltaire’s caustic wit first got him into trouble with the authorities in May 1716, when he was briefly exiled from Paris for composing poems mocking the French regent’s family. The young writer was unable to bite his tongue, however, and only a year later he was arrested and confined to the Bastille for writing scandalous verse implying the regent had an incestuous relationship with his daughter. Voltaire boasted that his cell gave him some quiet time to think, and he eventually did 11 months behind bars before winning a release. He later endured another short stint in the Bastille in April 1726, when he was arrested for planning to duel an aristocrat that had insulted and beaten him. To escape further jail time, he voluntarily exiled himself to England, where he remained for nearly three years.

3. He became hugely wealthy by exploiting a flaw in the French lottery.
In 1729, Voltaire teamed with mathematician Charles Marie de La Condamine and others to exploit a lucrative loophole in the French national lottery. The government shelled out massive prizes for the contest each month, but an error in calculation meant that the payouts were larger than the value of all the tickets in circulation. With this in mind, Voltaire, La Condamine and a syndicate of other gamblers were able to repeatedly corner the market and rake in massive winnings. The scheme left Voltaire with a windfall of nearly half a million francs, setting him up for life and allowing him to devote himself solely to his literary career.

4. He was an extraordinary prolific writer.
Voltaire wrote more than 50 plays, dozens of treatises on science, politics and philosophy, and several books of history on everything from the Russian Empire to the French Parliament. Along the way, he also managed to squeeze in heaps of verse and a voluminous correspondence amounting to some 20,000 letters to friends and contemporaries. Voltaire supposedly kept up his prodigious output by spending up to 18 hours a day writing or dictating to secretaries, often while still in bed. He may have also been fueled by heroic amounts of caffeine—according to some sources, he drank as many as 40 cups a day.

5. Many of his most famous works were banned.
Since his writing denigrated everything from organized religion to the justice system, Voltaire ran up against frequent censorship from the French government. A good portion of his work was suppressed, and the authorities even ordered certain books to be burned by the state executioner. To combat the censors, Voltaire had much of his output printed abroad, and he published under a veil of assumed names and pseudonyms. His famous novella “Candide” was originally attributed to a “Dr. Ralph,” and he actively tried to distance himself from it for several years after both the government and the church condemned it. Despite his best attempts to remain anonymous, Voltaire lived in almost constant fear of arrest. He was forced to flee to the French countryside after his “Letters Concerning the English Nation” was released in 1734, and he went on to spend the majority of his later life in unofficial exile in Switzerland.

6. He helped popularize the famous tale about Sir Isaac Newton and the apple.
Though the two never met in person, Voltaire was an enthusiastic acolyte of the English physicist and mathematician Sir Isaac Newton. Upon receiving a copy of Newton’s “Principia Mathematica,” he claimed he knelt down before it in reverence, “as was only right.” Voltaire played a key role in popularizing Newton’s ideas, and he offered one of the first accounts of how the famed scientist developed his theories on gravity. In his 1727 “Essay on Epic Poetry,” Voltaire wrote that Newton “had the first thought of his System of Gravitation, upon seeing an apple falling from a tree.” Voltaire wasn’t the original source for the story of the “Eureka!” moment, as has often been claimed, but his account was instrumental in making it a fabled part of Newton’s biography.

7. He had a brief career as a spy for the French government.
Voltaire struck up a lively correspondence with Frederick the Great in the late 1730s, and he later made several journeys to meet the Prussian monarch in person. Before one of these visits in 1743, Voltaire concocted an ill-advised scheme to use his new position to repair his reputation with the French court. After hatching a deal to serve as a government informant, he wrote several letters to the French giving inside dope on Frederick’s foreign policy and finances. Voltaire proved a lousy spy, however, and his plan quickly fell apart after Frederick grew suspicious of his motives. The two nevertheless remained close friends—some have even claimed they were lovers—and Voltaire later moved to Prussia in 1750 to take a permanent position in the Frederick’s court. Their relationship finally soured in 1752, after Voltaire made a series of scathing attacks on the head of the Prussian Academy of Sciences. Frederick responded by lambasting Voltaire, and ordered that a satirical pamphlet he had written be publically burned. Voltaire left the court for good in 1753, supposedly telling a friend, “I was enthusiastic about [Frederick] for 16 years, but he has cured me of this long illness.”

8. He never married or fathered children.
While Voltaire technically died a bachelor, his personal life was a revolving door of mistresses, paramours and long-term lovers. He carried out a famous 16-year affair with the brilliant—and very married—author and scientist Émilie du Châtelet, and later had a committed, though secretive, partnership with his own niece, Marie-Louise Mignot. The two lived as a married couple from the early 1750s until his death, and they even adopted a child in 1760, when they took in a destitute young woman named Marie- Françoise Corneille. Voltaire later paid the dowry for Corneille’s marriage, and often referred to Mignot and himself as her “parents.”

9. He set up a successful watchmaking business in his old age.
While living in Ferney, Switzerland, in the 1770s, Voltaire joined with a group of Swiss horologists in starting a watchmaking business at his estate. With the septuagenarian Voltaire acting as manager and financier, the endeavor soon grew into a village-wide industry, and Ferney watches came to rival some of the best in Europe. “Our watches are very well made,” he once wrote to the French ambassador to the Vatican, “very handsome, very good and cheap.” Voltaire saw the enterprise as a way to prop up the Ferney economy, and he used his vast network of upper class contacts to find prospective buyers. Among others, he eventually succeeded in peddling his wares to the likes of Catherine the Great of Russia and King Louis XV of France.

10. He continued causing controversy even in death.
Voltaire died in Paris in 1778, just a few months after returning to the city for the first time in 28 years to oversee the production of one of his plays. Over the last few days of his life, Catholic Church officials repeatedly visited Voltaire—a lifelong deist who was often critical of organized religion—in the hope of persuading him to retract his opinions and make a deathbed confession. The great writer was unmoved, and supposedly brushed off the priests by saying, “let me die in peace.” His refusal meant that he was officially denied a Christian burial, but his friends and family managed to arrange a secret interment in the Champagne region of France before the order became official.

A beginner’s guide to Voltaire, the philosopher of free speech and tolerance

The French are turning to Voltaire for guidance in the aftermath of the Charlie Hebdo attack. Here are his key quotes, misquotes, major works – and run-ins with the authorities

In the wake of the Charlie Hebdo massacre, French bookbuyers are turning to one of their grands philosophes, Voltaire, for enlightenment and perhaps Enlightenment. Publisher Gallimard is printing an extra 10,000 copies of his Treatise on Tolerance, which was brandished by participants in the Paris rallies of 11 January. In the treatise, Voltaire argues in favour of toleration of religious belief, while reserving the right to argue strenuously against it, and denouncing religious fanaticism of all stripes. “Tolerance has never provoked a civil war; intolerance has covered the Earth in carnage.”

Voltaire was the pen name of François-Marie Arouet, born in 1694: philosopher, novelist, playwright, all-round troublemaker and virtuoso of equal-opportunity ridicule. Since the early 20th century, he has also been doomed to be misquoted by those using him as a weapon in the free-speech wars. He never actually wrote “I disagree with what you say, but I will defend to the death your right to say it” – this excellent formulation was, rather, the work of his English biographer, Evelyn Beatrice Hall (who also used a pseudonym: SG Tallentyre), who used it to describe his “attitude” in her 1906 biography, The Friends of Voltaire.

Noted in an earlier biography is another bon mot, which Voltaire probably did say, in response to the same affair. Hearing that a rival philosopher’s book had been condemned by the authorities to be burned in public, Voltaire quipped: “What a fuss about an omelette!” (A splendidly backhanded defence.) Meanwhile, the instruction “Écrasez l’infâme!” (“Crush what is infamous”), signed on many of his letters, became something of a personal slogan against clerical abuses.

He was, after all, no stranger to getting in trouble with the authorities himself, and he couldn’t help provoking them. The early publication of a satirical poem accusing the Duc d’Orléans of having sex with his own daughter led, not totally unpredictably, to a stint in the Bastille. But Voltaire was able to put incarceration to productive use: it was there that he adopted his nom de plume (or perhaps guerre) and wrote his first play, Oedipe, a riff on the Sophoclean tragedy.

His most famous work remains Candide, a fiction in which the young titular hero is initiated into the mysteries of philosophical optimism. This is a satire on the philosophical theories of the great mathematician Gottfried Wilhelm Leibniz, who is immortally caricatured in its pages as one Professor Pangloss – hence our word “Panglossian”. All is for the best in this, the best of all possible worlds, insists Pangloss. By the end of the book, however, Candide himself is not so sure – nor, most probably, are those now reading Voltaire for the first time.

The following is an "In Our Time" programme on Candide. Enjoy

The following are a selection of videos that will help you understand the main principles of Voltaire's work.