Zwingli, and after him his disciple Bullinger, effected a change in the moral sentiment of Switzerland equivalent to that which a man would effect nowadays who should persuade men to discountenance or abandon military service of any kind for pay. One of the great obstacles to Zwingli’s success was his decided protest against the right of any Swiss to sell himself to foreign governments for the commission of bloodshed, regardless of any injury in justification; and it was mainly on that account that Bullinger succeeded in 1549 in preventing a renewal of the alliance or military contract between the cantons and Henry II. of France. ‘When a private individual,’ he said, ‘is free to enrol himself or not, and engages himself to fight against the friends and allies of his sovereign, I know not whether he does not hire himself to commit homicide, and whether he does not act like the gladiators, who, to amuse the Roman people, let themselves to the first comer to kill one another.’ But it is evident that, except with a reservation limiting a man’s service to a just national cause, Bullinger’s argument will also apply to the case of a hired soldier of his own country. The duty of every man to defend his country in case of invasion is intelligible enough; and it is very important to notice that originally in no country did the duty of military obedience mean more. In 1297 the High Constable and Marshal of England refused to muster the forces to serve Edward I. in Flanders, on the plea that neither they nor their ancestors were obliged to serve the king outside his dominions;[324] and Sir E. Coke’s ruling in Calvin’s case,[325] that Englishmen are bound to attend the king in his wars as well without as within the realm, and that their allegiance is not local but indefinite, was not accepted by writers on the constitution of the country. The existing militia oath, which strictly limits obedience to the defence of the realm, covered the whole military duty of our ancestors; and it was only the innovation of the military contract that prepared the way for our modern idea of the soldier’s duty as unqualified and unlimited with regard to cause and place and time. The very word _soldier_ meant originally stipendiary, his pay or _solde_ (from the Latin _solidum_) coming to constitute his chief characteristic. From a servant hired for a certain task for a certain time the steps were easy to a servant whose hire bound him to any task and for the whole of his life. The existing military oath, which binds a recruit and practically compels him as much to a war of aggression as of defence at the bidding of the executive, owes its origin to the revolution of 1689, when the refusal of Dumbarton’s famous Scotch regiment to serve their new master, William III., in the defence of Holland against France, rendered it advisable to pass the Mutiny Act, containing a more stringent definition of military duty by an oath couched in extremely general terms.