Some dangers are so spectacular and so much beyond normal experience that the mind refuses to accept them as real, and watches the approach of doom without any sense of apprehension. The man who looks at the onrushing tidal wave, the descending avalanche, or the spinning funnel of the tornado, yet makes no attempt to flee, is not necessarily paralyzed with fright or resigned to an unavoidable fate. He may simply be unable to believe that the message of his eyes concerns him personally. It is all happening to somebody else.

One of the great tragedies of mankind is that morality has been hijacked by religion.

Politicians should read science fiction, not westerns and detective stories.

Space can be mapped and crossed and occupied without definable limit; but it can never be conquered.

All human plans [are] subject to ruthless revision by Nature, or Fate, or whatever one preferred to call the powers behind the Universe.

Deep beneath the surface of the Sun, enormous forces were gathering. At any moment, the energies of a million hydrogen bombs might burst forth in the awesome explosion.... Climbing at millions of miles per hour, an invisible fireball many times the size of Earth would leap from the Sun and head out across space.

You can't have it both ways. You can't have both free will and a benevolent higher power who protects you from yourself.