All crowds, even those of animals, have an overwhelming craving to be led. A leader is needed to strike the spark to kindle the mass, give shape to its idea, and instigate its action. A crowd loves to adopt a leader to be its despot, and will be obedient and even servile to him who shows he can command. The leader influences the crowd by three means--_assertion_, _repetition_, and _example_. All these means are necessary to implant ideas in an unreasoning mass, and initiate unanimous action towards their realization. The _assertion_ must be concise and simple, and should epitomize the ideas which form the “religion” of the crowd. _Repetition_ is necessary to drive these ideas home. Reasoning is out of place, and has the worst effect, for crowds cannot reflect, and are as impatient of appeals to their reason as of opposition to their desires. The _example_ of the leader exercises a potent influence. A crowd is easily impressed by his coolness, courage, self-confidence, determination, and vigour in utterance and action, and even by his personal appearance. Leaders are generally men who are themselves carried away by the ideas they are striving to put in effect, although some have been calculating, cool, and astute. They are generally men of action, and action impresses when reason is unavailing. One quality leaders must have, and that is Will Power. A mere crowd has none, for the will of the individual becomes effaced when once he is united with his fellows, and the will of the leader must replace it, flashing out from his voice and his bearing, and felt in his words and his deeds. But the crowd will also react strongly on the leader, and may inspire him to a pitch far above his natural scope, but only on condition that the leader has among his qualities and his aims some that are germane to the “religion” of his followers, for the “Soul of the Crowd” to work on. What has been said of crowds and mobs applies in the main to the organized and trained mob which has become an army. A mass of soldiers differs from a mob mainly in the habits acquired by discipline, the facilities for action afforded by organization, and the ideal of character which their profession, and their very uniform, suggest to them to live up to. The discipline of the soldier, if it is to be worth anything in a crisis, must be so habitual as to be not reasoned, but instinctive. Under the strain of war, whether due to danger or to privation, habits can be relied on when reason fails. Discipline is not only the instinct of obedience, but that of reliance on leaders and comrades, both factors of enormous value in battle. It is this which gives troops the advantage over a mob. Psychologically they are both “dynamic crowds,” but the mob is devoid of the higher qualities which discipline has implanted in the soldier, and which the influences of his profession have rendered largely instinctive.