He was an author of fiction. They usually write a lot of stuff that is on some deeper level "true", even though it is on the surface fictional... And a lot of stuff that isn't.

Or sometimes both, because it's only part of the truth. Maybe the complete version should be: "An armed society is a 'polite' society, but with very frequent killings and not-infrequent massacres." I think I prefer living in a less "polite" society.