“True character arises from a deeper well than religion. It is the internalization of moral principles of a society, augmented by those tenets personally chosen by the individual, strong enough to endure through trials of solitude and adversity. The principles are fitted together into what we call integrity, literally the integrated self, wherein personal decisions feel good and true. Character is in turn the enduring source of virtue. It stands by itself and excites admiration in others.”

“Another principle that I believe can be justified by scientific evidence so far is that nobody is going to emigrate from this planet not ever....It will be far cheaper, and entail no risk to human life, to explore space with robots. The technology is already well along....the real thrill will be in learning in detail what is out there...It is an especially dangerous delusion if we see emigration into space as a solution to be taken when we have used up this planet....Earth, by the twenty-second century, can be turned, if we so wish, into a permanent paradise for human beings...”

“Human beings appear to be sufficiently selfish and calculating to be capable of indefinitely greater harmony and social homeostasis. This statement is not self-contradictory. True selfishness, if obedient to the other constraints of mammalian biology, is the key to a more nearly perfect social contract.”

“A society that condemns homosexuality harms itself. (254)”

“Science and technology are what we can do; morality is what we agree we should or should not do.”

“Human nature is deeper and broader than the artificial contrivance of any existing culture.”

“In the end ... success or failure will come down to an ethical decision, one on which those now living will be judged for generations to come.”