The Blue Cross (by GK Chesterton)
“Has it never struck you that a man who does next to nothing but hear men’s real sins is not likely to be wholly unaware of human evil? But, as a matter of fact, another part of my trade, too, made me sure you weren’t a priest.”
“What?” asked the thief, almost gaping.
“You attacked reason,” said Father Brown. “It’s bad theology.”