The man with a mother or sister fixation, the woman with a father or brother fixation should be made aware of it, however slight or severe the fixation may be. They must be made to realise that incestuous cravings are biological phenomena which for reasons of convenience have been made unlawful but which do not brand the individual experiencing them as a degenerate or a vicious person. They must also be made to realise that their incestuous craving may be one of the symptoms of the neurotic search for the line of least effort, knowledge of which weakens the craving to the point of insignificance. The individual with a biologically real incestuous fixation should accept it and seek its substitute gratification thru association with a suitable mate presenting in his or her person the fetishes of the loved parent or brother or sister. The individual whose fixation is purely neurotic should be freed of it by analysis and allowed to seek a mate without being inhibited by ghosts. CHAPTER VI THE PHYSIOLOGY OF LOVE A human being has met another human being of the opposite sex and is attracted to him or her by the conscious or unconscious memories which his or her physical and mental make up brings back. An organic compulsion drives a man to seek a certain woman who is to be his sexual mate. We say then that the man is in love. What is the tangible, observable, measurable meaning of the condition of being in love? To understand this clearly we must bear in mind the principle which modern psychology is gradually adopting, that of the unity of the organism. =The Organism is a Unit= which cannot, except for reasons of pure convenience, be split into entities of a contrasted character, such as body and mind, matter and soul, etc. To every physical phenomenon corresponds a simultaneous mental manifestation and vice versa. The body is the tangible aspect, the mind, the intangible aspect of the organism. Nor can any scientific distinction be drawn between the so-called grossness of the body and the spiritual quality of the mind. Nor can we establish in the body absolute lines of cleavage between the various organs, heart, stomach, liver or sexual organs. They are all closely interrelated and there again we find a profound unity of action. When the nerves of the "life division" of the autonomic nervous system are set working, the pupil will be contracted, the saliva flow, the heart beat more slowly, the stomach secrete gastric juice and churn food, the intestines push digested food toward the rectum, and the sexual organs fill up with blood.