§ 183
Furthermore Ellis admits, and quotes his authorities to show, that jealousy is “an emotion which is at its maximum among animals, among savages, among children, in the senile, in the degenerate, and very specially in chronic alcoholics.” He notes that the supreme artists and masters of the human heart, who have most consummately represented the tragedy of jealousy, clearly recognized that it is either atavistic or pathological. Shakespeare made his Othello a barbarian, and Tolstoy made the Pozdnischeff of his Kreutzer Sonata a lunatic. But the jealous person is above all (at least psychically) impotent and projects, on the most likely object, his own desires, which he cannot fulfill for himself.
Let every jealous husband ponder this. If he cannot utterly satisfy his wife erotically, he is jealous of other men simply because consciously or unconsciously he thinks some other man can. Also if he cannot, his inability probably proceeds either from ignorance of the art of love or from a foolish disbelief in his physical powers, a most common delusion in the ordinary man who is brought up in the tradition that sex activity involves a loss of vitality, instead of constituting, as it does, an exercise of the interstitial glands, whose functioning is necessary to the most robust health and success, both of which are inimical to or destructive of the emotion of jealousy.