1. It springs from the natural self, and everything that springs from the natural self has in it animal desire and lust; for the natural self is nothing but an abode and receptacle of animal desires and lusts, inasmuch as all blameworthy characteristics inherited from parents are seated there. 2. A fornicator casts his gaze upon the opposite sex indiscriminately and promiscuously, and does not direct it as yet to one of the sex; and as long as he is in that state, it is lust that moves him to do what he does. But according as he turns his eyes to one, and loves uniting his life with hers, his desire turns into chaste affection, and his lust into human love.