Their theology was such as to diminish the power of the Church. They abolished purgatory, from which the souls of the dead could be delivered by masses. They rejected the doctrine of Indulgences, upon which a large part of the papal revenue depended. By the doctrine of predestination, the fate of the soul after death was made wholly independent of the actions of priests.

Bertrand Russell, History of Western Philosop…, loc. 1933