[Footnote 238: Dugas, 'Observations sur des Erreurs "Formelles" de la Mémoire', _Revue Philosophique_, July 1908; _ib._ June 1910. Dugas makes no reference to Janet, nor to my paper on Hypnagogic Paramnesia, but his statement of the matter to some extent combines and harmonises those of the two earlier writers.]
[Footnote 239: P. Janet, 'A Propos du Déjà Vu,' _Journal de Psychologie Normale et Pathologique_, July-August 1905.]
[Footnote 240: H. Bergson, 'Le Souvenir du Présent et la Fausse Reconnaissance,' _Revue Philosophique_, December 1908. It should be remarked that, except in the attempt to explain why paramnesia is not normally habitual, Bergson's paper is based on the ideas or suggestions of previous writers.]
[Footnote 241: Before the appearance of my paper, as already mentioned, Anjel had emphasised the significance of fatigue in the production of paramnesia (_Archiv für Psychiatrie_, Bd. viii. pp. 57 _et seq._). His theory, indeed (only known to me through brief summaries)--according to which the pseudo-reminiscence is due to the tardy apprehension by the fatigued mind of a sensation which is thus degraded to the level of a reproduced impression--seems practically identical with that which I independently reached in the light of hypnagogic phenomena.]
[Footnote 242: I disregard those theories which invoke histological explanations, as by some peculiar disposition of the neurons. Such explanations are as much outside the psychologist's sphere as the old-fashioned explanations by reference to God and the Devil. A known physiological or pathological process may, indeed, quite properly be recognised by the psychologist; such, for instance, as the disturbance of the heart associated with some dreams. Even minute changes in the brain, when they have been properly determined by the histologist, may be effectively invoked by the psychologist if they seem to supply an exact physical correlative to his own findings. But for the psychologist to go outside his own field, and invent a purely fanciful and arbitrary neuronic scheme to suit a psychic process, explains nothing. It is merely child's play. The stuff that the psychologist works with must be psychical, just as the stuff of the physicist's work must be physical.]