If you can impress on any man with an absorbing conviction of the supreme importance of some moral or religious doctrine; if you can make him believe that those who reject that doctrine are doomed to eternal perdition; if you then give that man power, and by means of his ignorance blind him to the ulterior consequences of his own act — he will infallibly persecute those who deny his doctrine; and the extent of his persecution will be regulated by the extent of his sincerity.

Henry Thomas Buckle (1821-1862) English historian

History of Civilization in England, 1.4 (1858)