Loves born of lust are the most difficult to preserve, and every day of their life is a difficult and rare conquest. Even the most perfidious cunning of the arts of pleasing blunts against insurmountable difficulties, and woman, after having brought into play all the witchery of body and heart, may see her victim snatched away from her by the first comer. Love may be warm, ardent, thirsty, but the glass that satisfies it is always made of the most fragile crystal and may at any moment fall and be shattered into a hundred pieces. Revenge, which is a form of hatred, may, by incestuous nuptials, become a mother, or better, a stepmother of love. To be deceived and to know it, to wish to humiliate the guilty by flaunting in the latter's face a new love, to seek it, finding it in one day: there is the source of love out of revenge. The unfortunate paranymph who acts as the call-bird of a degraded passion does not always perceive the trap, allows himself to be loved, loves, and often amuses the person who pretends to love him and those who unconcernedly witness the shameful spectacle. Vanity makes us blind, and it does not permit us to see that, perhaps, in the period of a day we have been seen, desired, conquered; and while, inflated with pride, we display our feathers like a peacock, we do not realize that we are actors in a comedy staged to humiliate him or her who is loved always and more than ever. In some very humiliating cases we serve as rubefacient and sink so low as to be placed on a level with a mustard poultice or a leech; and the cure effected at our expense is so quick and perfect that we are immediately dismissed, like a physician who is impatiently paid and impatiently taken leave of because his services are no longer required. These, however, are the most unfortunate cases, and belong to the ugliest pathology of the human heart; in other instances love out of revenge becomes, through the virtue of either or both of the lovers, a true and real love which cures the old wound and opens a wide horizon of happiness to the man and to the woman who have become acquainted in such a strange manner, and it may then be said that he who was to be the revengeful executioner, the unconscious minister of the justice of love, becomes, instead, first the physician and afterward the lover of the offended, and a new love arises on the ruins of the old one.