We are rare and precious because we are alive, because we can think as well as we can. We are privileged to influence and perhaps control our future. I believe we have an obligation to fight for life on Earth - not just for ourselves, but for all those, humans and others, who came before us, and to whom we are beholden, and for all those who, if we are wise enough, will come after.
Carl SaganHuman history can be viewed as a slowly dawning awareness that we are members of a larger group.
Carl SaganWho are we, if not measured by our impact on others? Thatโs who we are! Weโre not who we say we are, weโre not who we want to be - we are the sum of the influence and impact that we have, in our lives, on others.
Carl SaganIn a lot of scientists, the ratio of wonder to skepticism declines in time. That may be connected with the fact that in some fields-mathematics, physics, some others-the great discoveries are almost entirely made by youngsters.
Carl SaganThere are many hypotheses in physics of almost comparable brillance and elegance that have been rejected because they did not survive such a confrontation with experiment. In my view, the human condition would be greatly improved if such confrontations and willingness to reject hypotheses were a regular part of our social, political, economic, religious and cultural lives.
Carl Sagan