Apart from the questions I have discussed there is another class of questions connected with war which present great difficulty. It is the right of men to abdicate their private judgment by entering into the military profession. In small nations this question is not of much importance, for in them wars are of very rare occurrence and are usually for self-defence. In a great empire it is wholly different. Hardly any one will be so confident of the virtue of his rulers as to believe that every war which his country wages in every part of its dominions, with uncivilised as well as civilised populations, is just and necessary, and it is certainly _primâ facie_ not in accordance with an ideal morality that men should bind themselves absolutely for life or for a term of years to kill without question, at the command of their superiors, those who have personally done them no wrong. Yet this unquestioning obedience is the very essence of military discipline, and without it the efficiency of armies and the safety of nations would be hopelessly destroyed. It is necessary to the great interests of society, and therefore it is maintained, strengthened by the obligation of an oath and still more efficaciously by a code of honour which is one of the strongest binding influences by which men can be governed. It is not, however, altogether absolute, and a variety of distinctions and compromises have been made. There is a difference between the man who enlists in the army of his own country and a man who enlists in foreign service either permanently or for the duration of a single war. If a man unnecessarily takes an active part in a struggle between two countries other than his own, it may at least be demanded that he should be actuated, not by a mere spirit of adventure or personal ambition, but by a strong and reasoned conviction that the cause which he is supporting is a righteous one. The conduct of a man who enlists in a foreign army which may possibly be used against his own country, and who at least binds himself to obey absolutely chiefs who have no natural authority over him, has been much condemned, but even here special circumstances must be taken into account. Few persons I suppose would seriously blame the Irish Catholics of the eighteenth century who filled the armies of France, Austria, Spain and Naples at a time when disqualifying laws excluded them, on account of their religion, from the British army and from almost every path of ambition at home. There is also perhaps some distinction between the position of a soldier who is obliged to serve, and a soldier in a country where enlisting is voluntary, and also between the position of an officer who can throw up his commission without infringing the law, and a private who cannot abandon his flag without committing a grave legal offence. At the beginning of the war of the American Revolution some English officers left the army rather than serve in a cause which they believed to be unrighteous.