The notion of "double consciousness" in Alfred Binet's psychological experimentalism.

Between 1889 and 1892, Binet published two remarkable essays, On Double Consciousness and Les alterations de la personnalité, which marked the end of a period of researches and interests closely linked to the doctrines on hypnosis and hysteria elaborated by the Ecole de la Salpêtrière. Later on, Binet was to abandon the utilization of hypnosis as a technique of experimentation, after he realized that the suggestibility of the "subjects" of these experiences had led to major experimental mistakes. However, during the years of his work at the Salpêtrière, he elaborated the notion of "double consciousness," which can be considered an alternative both to Ribot's idea of dissociation and to Janet's idea of disaggregation. The notion of double consciousness reveals both the originality of Binet's psychology--which was elaborated at the end of the nineteenth century--and its verifiable link to twentieth-century psychology. Unlike Janet, in fact, Binet did not support a theory of psychological deficiency or "misery," or of the retraction of the sphere of consciousness, which a normal capacity for psychological synthesis would oppose. On the contrary, Binet's psychology resulted in a theory stating that the duality of consciousness works in a perfect and autonomous way within the individual and, thanks to hypnosis, can be investigated in a laboratory.