The author discusses cases where the duplex personality of several different patients has been brought out with the use of hypnotism. Mason’s conclusion is that the second personality would have perceptive powers beyond the main personality. Clairvoyance is an attribute of this second personality and hypnotism is a way of bringing out this second personality in a controlled setting.
Mason argues the importance of recognizing and studying alternating personalities. He describes the awareness of the secondary personalities for each other and the primary personality, using the case of Madame B. to illustrate. The author identifies conditions in which the secondary personality has been observed: 1) spontaneously, 2) under hypnosis, 3) while asleep, and 4) as a result of pathologic conditions of the organism. The origin of personality as either a "product of a power inherent in nature" or "as an expression of organism" is discussed. The author concludes with consideration of the legal accountability of persons with alternating personalities.
This is a letter to the editor written by R. Osgood Mason about responses to his Nov. 30, 1895. Mason gives names of readings for background materials on hypnotism. He also responds to critics of his article. He also notes that one critic has since modified his view of hypnotism due to Mason’s article.