He or she who has been so unfortunate as to experience the pangs--or fangs--of jealousy will readily admit that it is one of the most painful, if indeed _not_ the most painful, of all human emotions. The suffering that it metes out to its victims is indescribable. No other single human emotion so affects the body, so upsets the mind, so deranges every function, as does jealousy. The torture that it causes makes the sufferer a truly pitiable object: the complete loss of sleep and complete loss of appetite may result in a serious impairment of the sufferer's health, while the rage it often gives rise to may lead to actual insanity, or at least to great mental disturbance. With good reason has popular fancy pictured this cursed emotion as a green-eyed monster. Jealousy is a primitive emotion. It is present not only in the primitive races, but even in animals. And being a primitive emotion, we can hardly hope to succeed in eradicating it entirely. Not in the immediate future, at any rate. But we can modify it. The statement frequently heard that "human nature is human nature" is only a platitudinous half-truth. The fundamental part of human nature--the desire for happiness and the avoidance of suffering--cannot be changed, nor would we want to change it if we could. It would mean the disappearance of the human race. But that many of our primitive emotions can be greatly modified by culture, by new standards, by new ideals of morality, about this there can be no question. Just as love in modern man is an entirely different feeling from what it was in primitive man, so jealousy in the advanced thinker is a different feeling from what it was in the savage; and by education and true culture it can be modified still further. We hope that in time to come--I will not venture to say how soon that time will be here--this injurious, degrading, anti-social feeling may be entirely or almost entirely eradicated from the human breast. The primitive desire--and this primitive desire of the race is still fully exhibited by children--is to take possession of everything nice or useful that somebody else has and which we have not. But our education and our cultural standards, including fear of punishment, have so repressed this desire, have put it so deeply in the background, that normal human beings hardly feel it at all. It is only improperly brought up people, mental defectives and those unable to adjust themselves to their environment who still have this primitive feeling of taking or stealing. And so with many other feelings and emotions; and so with jealousy.