Quotes from Carl Sagan

Why does Alexander the Great never tell us about the exact location of his tomb, Fermat about his Last Theorem, John Wilkes Booth about the Lincoln assassination conspiracy, Hermann Göring about the Reichstag fire? Why don't Sophocles, Democritus, and Aristarchus dictate their lost books?

Our politics, economics, advertising, and religions (New Age and Old) are awash in credulity. Those who have something to sell, those who wish to influence public opinion, those in power, a skeptic might suggest, have a vested interest in discouraging skepticism

All 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.

There were excesses in science and there were excesses in religion. A reasonable man wouldn't be stampeded by either one. There were many interpretations of Scripture and many interpretations of the natural world. Both were created by God, so both must be mutually consistent. Wherever a discrepancy seems to exist, either a scientist or a theologian—maybe both—hasn't been doing his job. Palmer

Ever been in love?' The question was direct, matter-of-fact. 'Halfway, half a dozen times. But'—she glanced at the nearest telescope—there was always so much noise, the signal was hard to find.

While the style of the critique may vary with the character of the critic, overly polite criticism benefits neither the proponents of new ideas nor the scientific enterprise.

It is very difficult to evolve by altering the deep fabric of life; any change there is likely to be lethal. But fundamental change can be accomplished by the addition of new systems on top of old ones…Thus evolution by addition and the functional preservation of the preexisting structure must occur for one of two reasons-either the old function is required as well as the new one, or there is no way of bypassing the old system that is consistent with survival.

Things had been falling down since the beginning of time.

Tyrants and autocrats have always understood that literacy, learning, books and newspapers are potentially dangerous. They can put independent and even rebellious ideas in the heads of their subjects.

Kepler's second law: A planet sweeps out equal areas in equal times. It takes as long to travel from B to A as from F to E as from D to C; and the shaded areas BSA, FSE and DSC are all equal.

Edmund Way Teale in his 1950 book Circle of the Seasons understood the dilemma better: It is morally as bad not to care whether a thing is true or not, so long as it makes you feel good, as it is not to care how you got your money as long as you have got it.

Each Voyager is itself a message. In their exploratory intent, in the lofty ambition of their objectives, in their utter lack of intent to do harm, and in the brilliance of their design and performance, these robots speak eloquently for us.