Avoidable human misery is more often caused not so much by stupidity as by ignorance, particularly our ignorance about ourselves.
Carl SaganOnce we overcome our fear of being tiny, we find ourselves on the threshold of a vast and awesome Universe that utterly dwarfs ā in time, in space, and in potential ā the tidy anthropocentric proscenium of our ancestors.
Carl SaganWe can judge our progress by the courage of our questions and the depth of our answers, our willingness to embrace what is true rather than what feels good.
Carl SaganQuickly capping 363 oil well fires in a war zone is impossible. The fires would burn out of control until they put themselves out... The resulting soot might well stretch over all of South Asia... It could be carried around the world... [and] the consequences could be dire. Beneath such a pall sunlight would be dimmed, temperatures lowered and droughts more frequent. Spring and summer frosts may be expected... This endangerment of the food supplies... appears to be likely enough that it should affect the war plans.
Carl SaganCenturies hence, when current social and political problems may seem as remote as the problems of the Thirty Years' War are to us, our age may be remembered chiefly for one fact: It was the time when the inhabitants of the earth first made contact with the vast cosmos in which their small planet is embedded.
Carl Sagan