The duties of officers, too, on the field of battle, were very different then from what they are now. An officer _now_ must be calm, collected, and quiet. His business is to plan, to calculate, to direct, and arrange. He has to do this sometimes, it is true, in circumstances of the most imminent danger, so that he must be a man of great self-possession and of undaunted courage. But there is very little occasion for him to exert any great physical force.