“Widespread intellectual and moral docility may be convenient for leaders in the short term, but it is suicidal for nations in the long term. One of the criteria for national leadership should therefore be a talent for understanding, encouraging, and making constructive use of vigorous criticism.”

“Some information is classified legitimately; as with military hardware, secrecy sometimes really is in the national interest. Further, military, political, and intelligence communities tend to value secrecy for its own sake. It's a way of silencing critics and evading responsibility - for incompetence or worse. It generates an elite, a band of brothers in whom the national confidence can be reliably vested, unlike the great mass of citizenry on whose behalf the information is presumably made secret in the first place. With a few exceptions, secrecy is deeply incompatible with democracy and with science.”

“Spaceflight, therefore, is subversive. If they are fortunate enough to find themselves in orbit, most people, after a little meditation, have similar thoughts. The nations that had instituted spaceflight had done so largely for nationalistic reasons; it was a small irony that almost everyone who entered space received a startling glimpse of a transnational perspective, of the Earth as one world.”

“To make a contented slave,’ [Frederick] Bailey later wrote, ‘it is necessary to make a thoughtless one. It is necessary to darken his moral and mental vision, and, as far as possible, to annihilate the power of reason.’ This is why the slaveholders must control what slaves hear and see and think. This is why reading and critical thinking are dangerous, indeed subversive, in an unjust society.”

“I maintain there is much more wonder in science than in pseudoscience. And in addition, to whatever measure this term has any meaning, science has the additional virtue, and it is not an inconsiderable one, of being true.”

“Since, in the long run, every planetary civilization will be endangered by impacts from space, every surviving civilization is obliged to become spacefaring--not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive... If our long-term survival is at stake, we have a basic responsibility to our species to venture to other worlds.”

“Every thinking person fears nuclear war, and every technological state plans for it.Everyone knows it is madness, and every nation has an excuse”