MOTHER. Will you generalize the character of this inclination or attraction in accordance with what we have just said? SON. The end of all attraction or inclination is the _production_, _progress_ and _preservation_ of beings. MOTHER. Are all instincts good which are merely inclinations or attractions? SON. For animals, which are subject to fatality, they are; because they tend directly to their end, without ever appearing to deviate from it. In our species, they are good in principle, if we regard their end; but they may become evil through the deviation to which our liberty subjects them. MOTHER. By what token can we know that our instinct has a right tendency? DAUGHTER. By comparing its use with its end; by assuring ourselves that this use is not prejudicial to the practice of justice, that it does not detract from the right of any of our faculties; that is, that it disturbs neither our individual harmony nor that of others; for it is on these conditions alone that it can coöperate in the realization of the social ideal. MOTHER. Very well. Now apply this general doctrine to human love, my children. SON. Since love is one of the forms of attraction, and since the general end of attraction is the production, progress and preservation of beings and species, it is evident that human love should possess these characteristics. Its principal function appears to me to be the reproduction of the species. DAUGHTER. It seems to me, brother, that this is not enough; since true husbands and wives do not cease to love each other after this end has been fulfilled, and since persons may love without having children. MOTHER. You are right, my daughter; our faculties being more numerous and more fully developed than those of the animals, our love cannot be incomplete like theirs; it cannot be of the same nature in our progressive species as in those species fatal and unprogressive of themselves. In us, each faculty, properly employed, aids in the improvement of all the rest, wrongly employed, it interrupts our harmony and lowers us; it is the same with our love. Or rather this passion is the one that most of all causes us to grow or to decline.