1,131 Quotes by Carl Sagan

In manned Earth orbital flights, still other problems arise. Consider a religious Muslim or Jew circling the Earth once every ninety minutes. Is he obligated to celebrate the Sabbath every seventh orbit? Spaceflight provides access to environments very different from those in which we and our customs have grown up.

Many of the problems facing us may be soluble, but only if we are willing to embrace brilliant, daring and complex solutions. Such solutions require brilliant, daring and complex people. I believe that there are many more of them around – in every nation, ethnic group and degree of affluence – than we realize.

Liberation from superstition is a necessary but not a sufficient condition for science.

One of the reasons for its success is that science has built-in, error-correcting machinery at its very heart. Some may consider this an overbroad characterization, but to me every time we exercise self-criticism, every time we test our ideas against the outside world, we are doing science. When we are self-indulgent and uncritical, when we confuse hopes and facts, we slide into pseudoscience and superstition. Every.

We tend not to be especially critical when presented with evidence that seems to confirm our prejudices.

The Sphinx is missing a nose. Someone shot it off in a moment of idle desecration – some say it was Mameluke Turks, others, Napoleonic soldiers.

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.

The fifth regular solid must then, they thought, correspond to some fifth element that could only be the substance of the heavenly bodies.

Predictions of surprising events always prove more accurate if not set down on paper beforehand.