In clinical practice, hallucinations are classified according to the modality through which they are experienced. They are always sensory, frequently indescribable sensations perceived as “real” by the subject. Persistent or evanescent, barren or full of content, these sensory perceptions are accompanied by varying affective components, which account for the associated feelings ranging from ecstasy to the severest pain. They are, by general agreement, recognized as having a common psychological origin, despite the wide spectrum of their manifestations. Psychoanalysis has demonstrated the analyzability of hallucinatory content where such is present, but a satisfactory theory to explain the psychogenesis of the phenomenon itself has not as yet been fully developed.
Any new clinical findings thus have a special pertinency, for they may provide data of significance leading to a verifiable psychoanalytic theory of hallucination. My investigations of hallucinated perceptions have been in progress for several years, and I
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