Since, in the long run, every planetary society will be endangered by impacts from space, every surviving civilization is obliged to become spacefaring — not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive.
Carl SaganWe are the only species on the planet, so far as we know, to have invented a communal memory stored neither in our genes nor in our brains. The warehouse of this memory is called the library
Carl SaganI would be very ashamed of my civilization if we did not try to find out if there is life in outer space.
Carl SaganYou mean am I for it or against it? You think this is a key question I'm going to be asked on Vega, and you want to make sure I give the right answer? Okay. Overpopulation is why I'm in favor of homosexuality and a celibate clergy. A celibate clergy is an especially good idea, because it tends to suppress any hereditary propensity toward fanaticism.
Carl SaganIt's perilous and foolhardy for the average citizen to remain ignorant about global warming, say, or ozone depletion, air pollution, toxic and radioactive wastes, acid rain, topsoil erosion, tropical deforestation, exponential population growth. Jobs and wages depend on science and technology.
Carl Sagan