P46: He who lives according to the guidance of reason strives, as far as he can, to repay the other’s Hate, Anger, and Disdain toward him, with Love, or Nobility.

Dem.: All affects of Hate are evil (by P45 C1). So he who lives according to the guidance of reason will strive, as far as he can, to bring it about that he is not troubled with affects of Hate (by P19), and consequently (by P37), will strive that the other also should not undergo those affects. Now Hate is increased by being returned, and on the other hand, can be destroyed by Love (by IIIP43), so that the Hate passes into Love (by IIIP44). Therefore, one who lives according to the guidance of reason will strive to repay the other’s Hate, etc., with Love, i.e., with Nobility (see its Def. in IIIP59 S), q.e.d.

Schol.: He who wishes to avenge wrongs by hating in return surely lives miserably. On the other hand, one who is eager to overcome Hate by Love, strives joyously and confidently, resists many men as easily as one, and requires the least help from fortune. Those whom he conquers yield joyously, not from a lack of strength, but from an increase in their powers.

All these things follow so clearly simply from the definitions of Love and of intellect, that there is no need to demonstrate them separately.