Carl Sagan

"We've arranged a civilization in which most crucial elements profoundly depend on science and technology. We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster."

"The nuclear arms race is like two sworn enemies standing waist deep in gasoline, one with three matches, the other with five."

"We 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."

"Extraordinary claims require extraordinary evidence."

"The idea that God is an oversized white male with a flowing beard, who sits in the sky and tallies the fall of every sparrow is ludicrous. But if by 'God,' one means the set of physical laws that govern the universe, then clearly there is such a God. This God is emotionally unsatisfying... it does not make much sense to pray to the law of gravity."

"Extraordinary claims require extraordinary evidence."

"We are star stuff harvesting sunlight."