Two Sorts of Discipline
The Soul and Body of an Army, General Ian Hamilton, G.C.B., 1921
Once more, there are two sorts of discipline, distinct in principle although sometimes they may overlap in practice.
The one is born in coercion and sets the soldier outside the ring of homely sentiment which surrounds the ordinary citizen from his cradle to his grave. … Coercive as the old discipline may be, it by no means despises the moral factor. It tries to make a religion out of something very near and real, yet, at the same time, high, intangible, romantic — the Regiment! …
The other sort of discipline aims at raising the work-a-day virtues of the average citizen to a higher power. It depends:
(1) Upon a sense of duty (res publica).
(2) Upon generous emulation (force of example).
(3) Upon military cohesion (esprit de corps).
(4) Upon the fear a soldier has of his own conscience (fear that he may be afraid).