More quotes by Carl Sagan

"Extraordinary claims require extraordinary evidence."
"A celibate clergy is an especially good idea, because it tends to suppress any hereditary propensity toward fanaticism."
"We can't help it. Life looks for life."
"The cosmos is within us. We are made of star-stuff. We are a way for the universe to know itself."
"I consider it an extremely dangerous doctrine, because the more likely we are to assume that the solution comes from the outside, the less likely we are to solve our problems ourselves."