“You can not argue with stupid but you can certainly play with it.”
“That's the first rule of command; be consistent! You can be sadistic, you can be lazy, you can be stupid, but if you're consistent the crew will still let you sit in when they play dominoes.”
“You can argue with someone's opinion, but you can't argue with their story.”
“You can't argue with insanity. You can stare at it, gaping and incredulous, but arguing with it is futile.”
“For Kant one can be both good and stupid; but for Aristotle stupidity of a certain kind precludes goodness.”
“It's one thing to be certain, but you can be certain and you can be wrong.”