The things that mankind has tested and found right make for harmony and progress — or peace; and the things it has found wrong hinder progress and make for discord. The right things lead to rational behavior — such as the substitution of reason for force — and so to freedom. The wrong things lead to brute force and slavery.
But the peace I describe is not passive. It must be won. Real peace comes from struggle that involves such things as effort, discipline, enthusiasm. This is also the way to strength. An inactive peace may lead to sensuality and flabbiness, which are discordant. It is often necessary to fight to lessen discord. This is the paradox.

Ch. 6 - Alone (1938)