Self-Control is the very essence of character. To be able to look a man straight in the eye, calmly and deliberately, without the slightest ruffle of temper under extreme provocation, gives a sense of power which nothing else can give. To feel that you are always, not sometimes, master of yourself, gives a dignity and strength to character, buttresses it, supports it on every side, as nothing else can. This is the culmination of thought mastery.

The Conquest of Worry (ed. 1924)