The second best thing about space travel is that the distances involved make war very difficult, usually impractical, and almost always unnecessary. This is probably a loss for most people, since war is our race's most popular diversion, one which gives purpose and color to dull and stupid lives. But it is a great boon to the intelligent man who fights only when he must-never for sport.

Citizenship is an attitude, a state of mind, an emotional conviction that the whole is greater than the part...and that the part should be humbly proud to sacrifice itself that the whole may live.

Never pick up a stray kitten . . . unless you've already made up your mind to be owned by it.

Never own more than you can carry in both hands at a dead run.

Humoring them costs nothing and adds to happiness in a world in which happiness is always in short supply.

God created men to test the souls of women.

Luck is a tag given by the mediocre to account for the accomplishments of genius.