Book 5
3
But the just in private transactions, although it is the equal in a sense (and the unjust the unequal), is not the equal according to geometrical but according to arithmetical proportion.That is, two pairs of terms (e.g. 1, 3; 7, 9), of which the second term exceeds the first by the same amount as the fourth exceeds the third. We do not call this a proportion at all, but, if also the third term exceeds the second by the same amount (e.g. 1, 3, 5, 7), an arithmetical progression. For it makes no differenceFor Corrective Justice the merits of the parties are immaterial. whether a good man has defrauded a bad man or a bad one a good one, nor whether it is a good or a bad man that has committed adultery; the law looks only at the nature of damage, treating the parties as equal, and merely asking whether one has done and the other suffered injustice, whether one inflicted and the other has sustained damage.
4
Hence the unjust being here the unequal, the judge endeavors to equalize it: inasmuch as when one man has received and the other has inflicted a blow, or one has killed and the other been killed, the lineAgain a diagram is employed, cf. 3.9,10, and infra 4.8. representing the suffering and doing of the deed is divided into unequal parts, but the judge endeavors to make them equal by the penalty or lossζημία has both senses. he imposes, taking away the gain.
5
(For the term gain is used in a general way to apply to such cases, even though it is not strictly appropriate to some of them, for example to a person who strikes another, nor is loss appropriate to the victim in this case;
