these are chiefly founded on mutual ease and convenience. Sometimes also they are arbitrary, at least dependent on a kind of capricious analogy, like many of the reasonings of lawyers.117
To carry the matter further, we may observe that it is impossible for men so much as to murder each other without statutes and maxims and an idea of justice and honour. War has its laws as well as peace, and even that sportive kind of war carried on among wrestlers, boxers, cudgel-players, gladiators, is regulated by fixed principles. Common interest and utility beget infallibly a standard of right and wrong among the parties concerned.