"Since jealousy is unfortunately a very common emotion in everyday experience and is felt frequently by a great majority of people, its use in stories and plays has been somewhat overdone. Certain schools of fiction portray jealousy as a proof of true love. This mistaken theory maintains that a lover can always tell when a woman begins to fall in love with him by observing when she begins to be jealous of other women. There is just enough truth in the theory to keep it alive long after psychology should have disposed of it."