“Emotions are the curse of logic.”

“Deep in the human unconscious is a pervasive need for a logical universe that makes sense. But the real universe is always one step beyond logic.”

“Clinging to any form of conservatism can be dangerous. Become too conservative and you are unprepared for surprises. You cannot depend on luck. Logic is blind and often knows only its own past. Logic is good for playing chess but is often too slow for the needs of survival.”

“Anything outside yourself, this you can see and apply your logic to it. But it’s a human trait that when we encounter personal problems, these things most deeply personal are the most difficult to bring out for our logic to scan. We tend to flounder around, blaming everything but the actual, deep-seated thing that’s really chewing on us.”

“If we deny the need for thought, Moneo, as some do, we lose the powers of reflection; we cannot define what our senses report. If we deny the flesh, we unwheel the vehicle which bears us. But if we deny emotion, we lose all touch with our internal universe. It was emotions which I missed the most.”

“Piter spoke to Jessica. "I'd thought of binding you by a threat held over your son, but I begin to see that would not have worked. I let emotion cloud reason. Bad policy for a Mentat.”

“Ah! Indeed but! But he consumes too much spice, eats it like candy. Look at his eyes! He might have come directly from the Arrakeen labor pool. Efficient, Piter, but he's still emotional and prone to passionate outbursts. Efficient, Piter, but he still can err. -Baron Vladimir”