Let us be honest. Did all the priests of Rome increase the mental wealth of man as much as Bruno? Did all the priests of France do as great a work for the civilization of the world as Diderot and Voltaire? Did all the ministers of Scotland add as much to the sum of human knowledge as David Hume? Have all the clergymen, monks, friars, ministers, priests, bishops, cardinals and popes, from the day of Pentecost to the last election, done as much for human liberty as Thomas Paine? — as much for science as Charles Darwin?

The Great Infidels (1881)