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.
