To discipline is to bring into habitual and complete subjection to authority; discipline is a severe word, and is often used as a euphemism for punish; to be thoroughly effective in war, soldiers must be disciplined as well as trained.
One especial psychological discipline which was apparently created for our sake is the psychology of law, the development of which, in Germany, Volkmar recounts.
There Rose entered into a new life, as different from that of the old physical freedom of the hills, and personal freedom from restraint, as could well be imagined, for, as Donald had told her, she was now mustered, as an untrained recruit, into a great modern army; and discipline is the keynote in war, whether the battle be against evil nations or evil forces.
These disciplines may be universal history and the history of culture, but certainly not memoirs, which always represent subjective experience and one-sided views.
Self-discipline and self-control are the beginnings of practical wisdom; and these must have their root in self-respect.