“Most deadly errors arise from obsolete assumptions.”

“Then, as his planet killed him, it occurred to Kynes that his father and all the other scientists were wrong, that the most persistent principles of the universe were accident and error.”

“I am a collection of the obsolete, a relic of the damned, of the lost and strayed. I am the waylaid pieces of history which sank out of sight in all of our pasts. Such an accumulation of riffraff has never before been imagined.”

“The assumption that humans exist within an essentially impermanent universe, taken as an operational precept, demands that the intellect become a totally aware balancing instrument.”

“What has mood to do with it? You fight when the necessity arises—no matter the mood! Mood's a thing for cattle or making love or playing the baliset. It's not for fighting.”

“Every judgment teeters on the brink of error,” Leto explained. “To claim absolute knowledge is to become monstrous. Knowledge is an unending adventure at the edge of uncertainty.”

“The assumption that a whole system can be made to work better through an assault on its conscious elements betrays a dangerous ignorance. This has often been the approach of those who call themselves scientists and technologists.”