From clinical observations the author concludes that in selected cases hashish weakens the will, makes a double personality, reveals subconscious tendencies, produces marked suggestibility and leaves a clear memory of the sensations and events occurring during the intoxication. Diminution of self-control and of voluntary attention, and the rapidity of flow of ideas, indicate that the higher centers are somewhat depressed. The conservation of memory and the feeling of dual personality prove that the higher centers are not completely paralyzed. The revelation of subconscious tendencies and, above all, the marked suggestibility indicate a dissociation of the conscious and the subconscious. The partial inhibition of the conscious and liberation of the subconscious mind appear to be the essential features of action of hashish.