Faith in science and progress was the driving force behind the first French Encyclopedia of Denis Diderot and Jean le Rond d'Alembert. The authority of the Catholic Church was weakened, partly by the conflicts between high and low clergy, partly by the conflict between the State and Jesuits, who were finally expelled from the Kingdom in 1764. The Protestants achieved legal status in France in 1787. The church hierarchy was in continual battle with the Lumieres, having many of their works banned, and causing French courts to sentence a Protestant, Jean Calas, to death in 1762 for blasphemy, an act which was strongly condemned by Voltaire.