More quotes by Carl Sagan

"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."
"Science is based on experiment, on a willingness to challenge old dogma, on an openness to see the universe as it really is. Accordingly, science sometimes requires courage - at the very least the courage to question the conventional wisdom."
"You could just as well say that an agnostic is a deeply religious person with at least a rudimentary knowledge of human fallibility."
"Science is a way of thinking much more than it is a body of knowledge."
"A celibate clergy is an especially good idea, because it tends to suppress any hereditary propensity toward fanaticism."