Love is the most complex, the most mysterious, the most unanalyzable of human emotions. It is based upon the difference in sex--upon the attraction of one sex for another. It is fostered by physical beauty, by daintiness, by a normal sexuality, by a fine character, by high aspirations, by culture and education, by common interests, by kindness and consideration, by pity, by habit and by a thousand other subtle feelings, qualities and actions, which are difficult of classification or enumeration. A great love, greatly reciprocated, is in itself capable of rendering a human being supremely happy. _Nothing else is._ Other things, such as wealth, power, fame, success, great discoveries, may give supreme satisfaction, great contentment, but supreme, buoyant happiness is the gift of a great love only. Such loves are rare, and the mortals that achieve it are the envy of the gods. But a great love, unreciprocated, especially when admixed to it is the feeling of jealousy, is the most frightful of tortures; it will crush a man like nothing else will, and the victims of this emotional catastrophe are pitied by the inmates of the lowest inferno. FOOTNOTES: [9] To avoid confusion, I will state here that I am discussing love between the opposite sexes, and not maternal love, homosexual love, love for one's country, etc. CHAPTER FIFTY-ONE JEALOUSY AND HOW TO COMBAT IT Jealousy the Most Painful of Human Emotions--Impairment of Health--Mental Havoc--Jealousy as a Primitive Emotion--Jealousy in the Advanced Thinker and in the Savage--Jealousy in the Child--Feelings and Environmental Factors--Essential Factors-- Vanity--Anger--Pain--Envy--The Impotent Husband's Jealousy-- Anti-social Qualities--The Jealous and the Unfaithful Husband-- Means of Eradicating the Evil--Iwan Bloch on the Question--Prof. Robert Michels' Statement--Remark of Prof. Von Ehrenfels--Havelock Ellis on Variation in Sexual Relationships--Advanced Ideas--Woman as Man's Chattel--The Change and the Changer--Teaching the Children--Casting Epithets at Jealousy--Free Unions and Jealousy-- Feelings, Actions and Public Opinion--The Adulterous Wife of the Present Day--Jealousy Defeating Its Own Object--Jealousy of Inanimate Objects.