In spite of all that fools have to say about the difficulty they have had in explaining love, there are certain principles relating to it as infallible as those of geometry; but in each character these are modified according to its tendency; hence the caprices of love, which are due to the infinite number of varying temperaments. If we were permitted never to see the various effects of light without also perceiving on what they were based, many minds would refuse to believe in the movement of the sun and in its oneness. Let the blind men cry out as they like; I boast with Socrates, although I am not as wise as he was, that I know of naught save love; and I intend to attempt the formulation of some of its precepts, in order to spare married people the trouble of cudgeling their brains; they would soon reach the limit of their wit. Now all the preceding observations may be resolved into a single proposition, which may be considered either the first or last term in this secret theory of love, whose statement would end by wearying us, if we did not bring it to a prompt conclusion. This principle is contained in the following formula: LVII. Between two beings susceptible of love, the duration of passion is in proportion to the original resistance of the woman, or to the obstacles which the accidents of social life put in the way of your happiness. If you have desired your object only for one day, your love perhaps will not last more than three nights. Where must we seek for the causes of this law? I do not know. If you cast your eyes around you, you will find abundant proof of this rule; in the vegetable world the plants which take the longest time to grow are those which promise to have the longest life; in the moral order of things the works produced yesterday die to-morrow; in the physical world the womb which infringes the laws of gestation bears dead fruit. In everything, a work which is permanent has been brooded over by time for a long period. A long future requires a long past. If love is a child, passion is a man. This general law, which all men obey, to which all beings and all sentiments must submit, is precisely that which every marriage infringes, as we have plainly shown. This principle has given rise to the love tales of the Middle Ages; the Amadises, the Lancelots, the Tristans of ballad literature, whose constancy may justly be called fabulous, are allegories of the national mythology which our imitation of Greek literature nipped in the bud. These fascinating characters, outlined by the imagination of the troubadours, set their seal and sanction upon this truth. LVIII. We do not attach ourselves permanently to any possessions, excepting in proportion to the trouble, toil and longing which they have cost us.