"When a man thinks he has enough of evidence for some notion of his he sometimes refuses to listen to any additional evidence pro or con, saying, “It is a settled question, probatis probata; it needs no evidence; it is certain.” This is knowledge as distinguished from faith. He says, “I do not believe; I know.” “ If any man thinketh that he knoweth, he knoweth yet nothing as he ought to know.'' This knowledge is a shutting of one's ears to all arguments, and is the same as “Implicit faith” in one of its meanings."

James Clerk Maxwell (1850)