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.
— Robert A. Heinlein, Time Enough For Love – 1973 (via trevoredwards)