A single message from space will show that it is possible to live through technological adolescence. . . . It is possible that the future of human civilization depends on the receipt of interstellar messages.
Carl SaganWe are not smart enough to decide which pieces of knowledge are permissible and which are not.
Carl SaganI set before you two ways: You can use your technology to destroy yourselves or to carry you to the planets and the stars. It's up to you.
Carl SaganBooks are like seeds. They can lie dormant for centuries and then flower in the most unpromising soil.
Carl SaganNational boundaries are not evident when we view the Earth from space. Fanatical ethnic or religious or national chauvinisms are a little difficult to maintain when we see our planet as a fragile blue crescent fading to become an inconspicuous point of light against the bastion and citadel of the stars.
Carl Sagan