3. The study of Civil and Canon Law flourished in the Middle Ages, while moral science, which is the study of the Natural Law, was still in its infancy. No wonder that the mediaeval jurists occasionally formulated maxims, which can only be squared with the principles of Natural Law by an exceeding amount of interpretation,--which are in fact much better dropped, quoted though they sometimes be by moralists of repute. One such maxim is this, that _a wrong-doer becomes the subject of the injured party by reason of the offence_. Admit this, and you can hardly keep clear of Locke's doctrine of the origin of civil power, (s. ii., _per totum_, p. 307; cf. Suarez, _De Caritate_, d. xiii., s. iv., nn. 5, 6). 4. We have only to repeat about war what we said of self-defence, that all the killing that takes place in it is _incidental_, or _indirect_. The cannon that you see in Woolwich Arsenal, the powder and torpedoes, have for their end what St. Thomas (_De Potentia_, q. 7, art. 2, ad 10) declares to be the end and object of the soldier, "to upset the foe," to put him _hors de combat_. This is accomplished in such rough and ready fashion, as the business admits of; by means attended with incidental results of extremest horror. But no sooner has the bayonet thrust or the bullet laid the soldier low, and converted him into a non-combatant, than the ambulance men are forward to see that he shall not die. If indeed even in the dust he continues to be aggressive, like the wounded Arabs at Tel-el-Kebir, he must be quieted and repressed a second time. Probably he will not escape with life from a second repression: still, speaking with philosophic precision, we must say that "to quiet, not to kill him," is, or should be, the precise and formal object of the will of his slayer in war. St. Thomas indeed (2a 2æ, q. 64, art. 7, in corp.) seems to allow the soldier fighting against the enemy to mean to kill his man. But by _enemy_ in this passage we should probably understand _rebel_. The soldier spoken of is the instrument of the feudal lord bringing back to duty his rebellious vassal. In the Middle Ages, till the end of the fifteenth century, the notion of independent nations scarcely found place. In war, as all cases of self-defence, the killing is indirect. In capital punishment, on the other hand, the killing is direct: it being _chosen as a deterrent means_, that the offender be "hanged by the neck" till he is "dead, dead, dead." This disposes of the error, that capital punishment is an act of self-defence on the part of the State against evildoers. We may observe finally that by the right of the sword, and by that alone, not in self-defence, not in war, but by the hand of public justice raised against a guilty subject, can human life ever be taken _directly_. _Reading_.--St. Thos., 2a 2æ, q. 40, art. 1. SECTION X.--_Of the Scope and Aim of Civil Government_.