I think if we ever reach the point where we think we thoroughly understand who we are and where we came from, we will have failed.
Carl SaganIt is the tension between creativity and skepticism that has produced the stunning and unexpected findings of science.
Carl SaganPhilosophers and scientists confidently offer up traits said to be uniquely human, and the monkeys and apes casually knock them down -- toppling the pretension that humans constitute some sort of biological aristocracy among the beings on Earth.
Carl SaganBy exploring other worlds we safeguard this one. By itself, I think this fact more than justifies the money our species has spent in sending ships to other worlds. It is our fate to live during one of the most perilous and, at the same time, one of the most hopeful chapters in human history.
Carl SaganAll of us cherish our beliefs. They are, to a degree, self-defining. When someone comes along who challenges our belief system as insufficiently well-based - or who, like Socrates, merely asks embarrassing questions that we haven't thought of, or demonstrates that we've swept key underlying assumptions under the rug - it becomes much more than a search for knowledge. It feels like a personal assault.
Carl Sagan