I believe that this hairless embryo with the aching, oversize brain case and the opposable thumb, this animal barely up from the apes, will endure --will endure longer than his home planet, will spread out to the other planets, to the stars, and beyond, carrying with him his honesty, his insatiable curiosity, his unlimited courage --and his noble essential decency. This I believe with all my heart.

Since survival is the sine qua non, I now define the "moral behavior" as "behavior that tends toward survival".

You can go wrong by being too skeptical as readily as by being too trusting.

We learned not to waste ammo even on warriors except in self-protection

Once you get to earth orbit, you're halfway to anywhere in the solar system.

I've found out why people laugh. They laugh because it hurts- because it's the only thing that'll make it stop hurting... I had been told that a 'funny' thing is a thing of goodness. It isn't... The goodness is in the laughing. I grok it is a bravery- and a sharing- against pain and sorrow and defeat.

If you wanted to teach a baby a lesson, would you cut its head off?