4. Moreover if lex is in accordance with reason, all that is in accordance with reason will be lex, as far as it agrees with religion, is in harmony with knowledge, and is beneficial for salvation. And consuetudo is so-called because it is in common use.
Chapter 4. On jus naturale.
1. Jus is either natural, or civil, or universal (jus gentium). Jus naturale is what is common to all peoples, and what is observed everywhere by the instinct of nature rather than by any ordinance, as the marriage of man and woman, the begetting and rearing of children, the common possession of all,[295] the one freedom of all, the acquisition of those things that are taken in the air or sea or on the land.
2. Likewise the restoring of property entrusted or lent, the repelling of violence by force. For this, or whatever is like this, is nowhere considered unjust, but natural and fair.
Chapter 5. On jus civile.
1. Jus civile is what each people or state has enacted as its own law, for human and divine reasons.
Chapter 6. On jus gentium.
1. Jus gentium is the seizing, building, and fortifying of settlements, wars, captivities, servitudes, postliminies, treaties, peaces, truces, the obligation not to violate an ambassador, the prohibition of intermarriage with aliens. And [it is called] jus gentium because nearly all nations observe it.
Chapter 7. On jus militare.
1. Jus militare is the ceremony of beginning war, the obligation in making a treaty, the going out against the enemy when the signal is given, and the joining of battle; likewise the retreat when the signal is given; likewise the punishment of a soldier’s fault if a post should be deserted. Likewise the amount of pay, the grades of office, and the honor of rewards, as when a crown or a necklace is given.