Voltaire is widely known as the author of a literary masterpiece, Candide, while his reputation as a thinker rests largely on his Philosophical Letters and Philosophical Dictionary. He is equally renowned as a critic of the forces of superstition and fanaticism, and a champion of freedom of thought and belief. The works presented here, in a new English translation, are among the most important and characteristic texts of the Enlightenment, and bring together all three aspects of Voltaire: the writer, the doer and the philosophe. Originating in Voltaire’s campaign to exonerate Jean Calas, they are works of polemical brilliance, informed by his deism and humanism and by Enlightenment values and ideals more generally. The issues which they raise, concerning questions of tolerance and human dignity, are still highly relevant to our own times. This volume presents them together with an introduction by Simon Harvey and useful notes on further reading.