377. 12. One finds a jealousness also in regard to mistresses, but not such as arises in regard to wives. Jealousness in regard to wives springs from the inmost elements in a person, whereas jealousness in regard to mistresses springs from the outmost elements, so that they are different in character.
Jealousness in regard to wives springs from the inmost elements, because that is where conjugial love has its seat. It has its seat there, because by its sworn eternity established by covenant, and also by the equality of right by which what belongs to one belongs to the other, marriage unites souls and binds the deeper levels of their minds. Once implanted, this union and bond remains unsundered, whatever love exists between them later, be it warm or cold.
[2] (That is why an overture to lovemaking on the part of a wife chills a man totally from inmosts to outmosts, whereas an overture to lovemaking on the part of a mistress does not so chill a lover.)
Jealousness in regard to a wife has attached to it the wish for a good name, to preserve one's honor; and this subsidiary reason for jealousness does not exist in regard to a mistress.
Still, however, these two kinds of jealousness each vary, depending on the seat of the love received from the wife or of that received from the mistress, and depending at the same time on the state of the judgment of the man receiving it.