The strategic principle, that armies should act in masses on the offensive, and should break up into smaller groups for retreat, unconsciously confirms the truth that the force of an army depends on its spirit. To lead men forward under fire needs more discipline (which can only be attained by marching in masses) than is needed for self-defence when attacked. But this rule, which leaves out of sight the spirit of the army, is continually proving unsound, and is strikingly untrue in practice in all national wars, when there is a great rise or fall in the spirit of the armies.

The French, on their retreat in 1812, though they should, by the laws of tactics, have defended themselves in detached groups, huddled together in a crowd, because the spirit of the men had sunk so low that it was only their number that kept them up. The Russians should, on the contrary, by the laws of tactics, have attacked them in a mass, but in fact attacked in scattered companies, because the spirit of the men ran so high that individual men killed the French without orders, and needed no compulsion to face hardships and dangers.