Jean Calas (1698 – 10 March 1762) was a merchant living in Toulouse, France, famous for having been the victim of a biased trial due to his being a Protestant. In France, he is a symbol of Christian religious intolerance, along with Jean-François de la Barre and Pierre-Paul Sirven.
Calas, along with his wife, was a Protestant. France was then a mostly Roman Catholic country; Catholicism was the state religion, with no legal recognition granted to minority faiths. While the harsh oppression of Protestantism initiated by King Louis XIV had largely receded, Protestants were, at best, tolerated. Louis, one of the Calas's sons, converted to Catholicism in 1756. On 13–14 October 1761, another of the Calas sons, Marc-Antoine, was found dead on the ground floor of the family's home. Rumors had it that Jean Calas had killed his son because he, too, intended to convert to Catholicism. The family, interrogated, first claimed that Marc-Antoine had been killed by a murderer. Then they declared that they had found Marc-Antoine dead, hanged; since suicide was then considered a heinous crime against oneself, and the dead bodies of suicides were defiled, they had arranged for their son's suicide to look like a murder.
Despite overwhelming evidence that the death was a suicide, including the testimony of Jeanne Vigneire, Calas' Catholic governess, the court in Toulouse held that Jean Calas had murdered his son. Calas was tortured in an attempt to get him to admit that he was guilty. His arms and legs were stretched until they pulled out of their sockets. Thirty pints (slightly less than 4 gallons) of water were poured down his throat. He was tied to a cross in the cathedral square where each of his limbs were broken twice by an iron bar. Yet with all this torture he continued to declare his innocence.
On 9 March 1762, the parlement (regional legislature that also tried cases) of Toulouse sentenced Jean Calas to death on the wheel. On 10 March, at the age of 64, he died tortured on the wheel, while still very firmly claiming his innocence.
Voltaire, contacted about the case, after initial suspicions that Calas was guilty of anti-Catholic fanaticism had subsided, began a campaign to get Calas's sentence overturned. He claimed that Marc-Antoine had committed suicide because of gambling debts and not being able to finish his university studies due to his confession. Voltaire's efforts were successful: king Louis XV received the family, and had the sentence annulled in 1764. The king fired the chief magistrate of Toulouse, the Capitoul. The trial was done over by another court and in 1765 the unfortunate Jean Calas was posthumously exonerated on all charges. His family was paid 36,000 Francs by the king in compensation.