“A sophisticated human can become primitive. What this really means is that the human's way of life changes. Old values change, become linked to the landscape with it's plants and animals. This new existence requires a working knowledge of those multiplex and cross-linked events usually referred to as Nature. It requires a measure of respect for the inertial power within such natural systems. When a human gains this knowledge and respect, that is called "being primitive". The converse, of course, is equally true: the primitive human can become sophisticated, but not without incurring dreadful psychological damage.”

“Beyond a critical point within a finite space, freedom diminishes as numbers increase. This is as true of humans as it is of gas molecules in a sealed flask. The human question is not how many can possibly survive within the system, but what kind of existence is possible for those who so survive.”

“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.”

“Humans are born with a susceptibility to that most persistent and debilitating disease of intellect: self-deception. The best of all possible worlds and the worst get their dramatic coloration from it. As nearly as we can determine, there is no natural immunity. Constant alertness is required.”

“Nature does not make mistakes. Right and wrong are human categories.”

“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.”

“A human being - what is a human being? Everything and nothing. Through the power of thought it can mirror everything it experiences. Through memory and knowledge it becomes a microcosm, carrying the world within itself. A mirror of things, a mirror of facts. Each human being becomes a little universe within the universe!”