“What kind of intelligent beings would evolve on a planet that is all mountains?” “Stupid ones!” Casker said. - Robert Sheckley

Society as a whole, he reminded himself, must be protected against the individual, just as a human body must be protected against malfunction of any of its parts. As fond as you might be of your gall bladder, you would sacrifice it mercilessly if it were going to impair the rest of you.

Could he be an imposter?" the venerable priest mused. "No, I suppose not. So he must be from some other universe. That's the usual explanation for the inexplicable.

Few individuals of any race murder for pleasure. There are perfectly adequate reasons to kill, though, reasons which might satisfy any philosopher.
But, once accepted, there are more reasons, and more and more. And murder, once accepted, is hard to stop. It leads irresistibly to war and, from there, to annihilation.