P51: Favor is not contrary to reason, but can agree with it and arise from it.

Dem.: For Favor is a Love toward him who has benefited another (by Def. Aff. XIX), and so can be related to the Mind insofar as it is said to act (by IIIP59), i.e. (by IIIP3), insofar as it understands. Therefore, it agrees with reason, etc., q.e.d.

Alternate dem.: He who lives according to the guidance of reason, desires for the other, too, the good he wants for himself (by P37). So because he sees someone benefiting another, his own striving to do good is aided, i.e. (by IIIP11 S), he will rejoice.

And this Joy (by hypothesis) will be accompanied by the idea of him who has benefited another. He will, therefore (by Def. Aff. XIX), favor him, q.e.d.

Schol.: Indignation, as we define it (see Def. Aff. XX), is necessarily evil (by P45). But it should be noted that when the supreme power, bound by its desire to preserve peace, punishes a citizen who has wronged another, I do not say that it is indignant toward the citizen. For it punishes him, not because it has been aroused by Hate to destroy him, but because it is moved by duty.