By 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 SaganHuman history can be viewed as a slowly dawning awareness that we are members of a larger group Groups of people from divergent ethnic and cultural backgrounds working in some sense together [is] surely a humanizing and character building experience. If we are to survive, our loyalties must be broadened further, to include the whole human community, the entire planet Earth.
Carl SaganAs agonizing a disease as cancer is, I do not think it can be said that our civilization is threatened by it. ... But a very plausible case can be made that our civilization is fundamentally threatened by the lack of adequate fertility control. Exponential increases of population will dominate any arithmetic increases, even those brought about by heroic technological initiatives, in the availability of food and resources, as Malthus long ago realized.
Carl Sagan...the idea of a spiritual part of our nature that survives death, the notion of an afterlife, ought to be easy for religions and nations to sell. This is not an issue of which we might anticipate widespread skepticism. People will want to believe it, even if the evidence is meager to nil... compelling testimony ... provides that our personality, character, memory ... resides in the matter of the brain, it is easy not to focus on it, to find ways to evade the weight of the evidence.
Carl SaganThe Romans called the Christians atheists. Why? Well, the Christians had a god of sorts, but it wasn't a real god. They didn't believe in the divinity of apotheosized emperors or Olympian gods. They had a peculiar, different kind of god. So it was very easy to call people who believed in a different kind of god atheists. And that general sense that an atheist is anybody who doesn't believe exactly as I do prevails in our own time.
Carl Sagan