Who said “I disapprove of what you say, but I will defend till death your right to say it”?

Voltaire said that “I disapprove of what you say, but I will defend till death your right to say it”. Voltaire was a prolific writer, producing works in almost every literary form including plays, poetry, novels, essays, and historical and scientific works. He wrote more than 20,000 letters and more than 2,000 books and pamphlets.