From A Recent Carnival of Crime in Connecticut by Mark Twain

"Now tell me, why is it that a conscience can't haul a man over the coals once, for an offense, and then let him alone? Why is it that it wants to keep on pegging at him, day and night and night and day, week in and week out, forever and ever, about the same old thing? There is no sense in that, and no reason in it. I think a conscience that will act like that is meaner than the very dirt itself."