Click on this link to read an excerpt from Voltaire’s A Treatise on Tolerance (1763).

The Treatise on Tolerance on the Occasion of the Death of Jean Calas from the Judgment Rendered in Toulouse (Pieces Originales Concernant la Mort des Sieurs Calas det le Jugement rendu a Toulouse) is a work by French philosopher Voltaire, published in 1763, in which he calls for tolerance between religions, and targets religious fanaticism, especially that of the Jesuits (under whom Voltaire received his early education), indicting all superstitions surrounding religions.

Voltaire’s work follows the trial of Jean Calas (1698-1762), a Protestant accused of murdering his son Marc-Antoine to prevent his conversion to the Church and executed in Toulouse on March 10, 1762 despite enduring torture after the prosecution used perjured witnesses, in a case which Voltaire took to display Catholic prejudice and fanaticism. In 1765, after the king fired the chief magistrate and the case was retried by another court, Calas was posthumously exonerated and his family paid 36 thousand francs.