Voltaire was the pen name of François-Marie Arouet, a French Enlightenment writer, historian, and philosopher.

He was a prolific writer, known for his wit and his satirical critiques of the French monarchy and the Catholic Church.

Voltaire was a passionate advocate for freedom of speech, freedom of religion, and the separation of church and state.

He is famously associated with the principle, 'I disapprove of what you say, but I will defend to the death your right to say it.'

His most famous work is the satirical novella 'Candide,' which mocks philosophical optimism and exposes religious intolerance.

He fought tirelessly against injustice, most notably in the Calas affair, where he worked to exonerate a Protestant man wrongfully executed.

His famous motto was 'Écrasez l’infâme' ('Crush the infamous thing'), referring to religious bigotry and superstition.

He was a Deist, believing in a rational creator but rejecting the rituals and dogmas of organized religion.

He corresponded with several 'enlightened monarchs,' such as Frederick the Great of Prussia.

Voltaire's ideas were immensely influential on the leaders of both the American and French Revolutions.