The principal drift of our argument rests upon these justifiable causes, to which the sentiment of Coriolanus in Dionysius of Halicarnassus, particularly applies, he says, "in the first place, I beseech you to consider how you may find pious and just pretexts for the war." And Demosthenes in his second Olynthiac, makes a similar observation, "I think, _says he_, that as in a ship, or house, or any other fabric, the lowest parts ought to be the strongest; so in all political measures the motives and pretexts ought to be laid deeply in the principles of truth and justice." The following language of Dion Cassius is no less applicable to the question. "Justice must be made the principal ground of our actions. For with such support there is the best hope of success to our arms. But without that, any point which may be gained for the moment has no firm ground to rest upon." To which may be added, the words of Cicero, who maintains those wars to be unjust, which are made without sufficient cause. And in another place, he reproves Crassus for having intended to pass the Euphrates, when there was no cause of war. Which is no less true of public than of private wars. Hence come the complaints of Seneca, "Why do we restrain homicide, and the murder of individuals, but glory in the crime of slaughter, which destroys whole nations? Avarice and cruelty know not any bounds. By decrees of the Senate, and of the people cruel acts are authorized, and measures, which are pursued by order of the state, are forbidden to individuals." Wars indeed undertaken by public authority are attended with certain effects of right, and have the sanction of opinion in their favour. But they are not the less criminal, when made without just cause. For which reason Alexander was not improperly styled a robber by the Scythian ambassadors, as may be seen in Quintus Curtius. Seneca and Lucan give him the same appellation; the Indian sages call him a madman; and a pirate once presumed to rank him with his own class. Justin speaks of Philip in the same terms, who, _says he_, in deciding a dispute between two rival kings, stripped both of their dominions with all the treachery and violence of a robber. Augustin has a pertinent remark on this subject. He says, what are unjustly acquired dominions, but the spoils of robbery? In the same strain, Lactantius says, "Men, captivated with the appearances of vain glory, give the names of virtues to their crimes." Injury, or the prevention of injury forms the only justifiable cause of war. "And, _in the language of the same Augustin_, all the evil consequences of war are to be laid at the door of the aggressor." Thus the Roman Herald in a declaration of war makes a solemn appeal against the aggressor, as having violated the laws of nations, and refused proper satisfaction.