Book 5
1
Political Justice is of two kinds, one natural, the other conventional. A rule of justice is natural that has the same validity everywhere, and does not depend on our accepting it or not. A rule is conventional that in the first instance may be settled in one way or the other indifferently, though having once been settled it is not indifferent: for example, that the ransom for a prisoner shall be a mina, that a sacrifice shall consist of a goat and not of two sheep; and any regulations enacted for particular cases, for instance the sacrifice in honor of Brasidas,The Spartan Brasidas detached Amphipolis from the Athenian empire 424 B.C., and fell defending it against Cleon 422. He was worshipped as a hero by the city, with games and yearly sacrifices (Thuc. 5.11). and ordinances in the nature of special decrees.
2
Some people think that all rules of justice are merely conventional, because whereas a law of nature is immutable and has the same validity everywhere, as fire burns both here and in Persia, rules of justice are seen to vary.
