[221] Descartes compares the animal mechanism to that of the grottos and fountains at Versailles, the nerves to the water-tubes:—“Les objets extérieurs qui par leur seul présence, agissent contre les organes des sens, et qui par ce moyen, la déterminent à se mouvoir en plusieurs diverses façons, selon comme les parties du cerveau sont disposées, sont comme les étrangers, qui entrant dans quelques unes des grottes de ces fontaines causent euxmêmes sans y penser les mouvements qui s’y font en leur présence: car ils n’y peuvent entrer qu’en marchant sur certains carreaux tellement disposés, que s’ils approchent d’une Diane qui se baigne, ils la font cacher dans les roseaux; et s’ils passent outre pour la poursuivre, ils feront venir vers eux un Neptune qui les menacera de son trident; ou s’ils vont de quelque autre costé, ils en feront sortir un monstre marin qui leur vomira de l’eau contre la face.”—Traité de l’Homme, 1664, p. 12. Ingenious as the comparison is, it only illustrates how machines may be constructed to imitate animal actions. Diana always hides herself when a certain spot is trodden upon; and Neptune always appears when another spot is trodden upon. There is no fluctuation, no sensibility discerning differences and determining variations. Compare the following experiment: A monkey was placed on the table and a shrill whistle made close to its ear: “Immediately the ear was pricked and the animal turned with an air of intense surprise, with eyes widely opened and pupils dilated, to the direction whence the sound proceeded. On repetition of the experiment several times, though the pricking of the ear and the turning of the head and eyes constantly occurred, the look of surprise and dilatation of the pupils ceased to be manifested.”—Ferrier, The Functions of the Brain, 1876, p. 171. A mechanical monkey would always have reacted in precisely the same way on each stimulus.
[222] Printed in the Fortnightly Review, November, 1874, from which all my citations are made.
[223] Schiff, Lehrbuch der Physiol., 1858, p. 212. Hermann, Physiology, translated by Gamgee, 1875, p. 511.
[224] Meanwhile the reader is referred to Schröder van der Kolk, Pathologie der Geisteskrankheiten, 1863, p. 51; or Jessen, Physiologie des menschlichen Denkens, 1872, p. 66.
[225] Griesinger, Les Maladies Mentales, p. 96.
[226] M. Luys cites the case of a patient who conversed quite rationally with a visitor “sans en avoir conscience, et ne se souvenait de rien”; and he draws the extraordinary conclusion that the conversation “s’opérait en vertu des forces réflexes.”—Études de Physiologie et de Pathologie Cérébrales, 1874, p. 117. Is it not obvious that the patient must have been conscious at the time, though the consciousness vanished like that in a dream? The persistent consciousness is the continuous linking on of one state with previous states—the apperception of the past.
[227] Abercrombie, Inquiries concerning the Intellectual Powers, 1840, p. 151. Wigan, The Duality of the Mind, 1844, p. 270. Despine, La Psychologie Naturelle, 1868, I. 54.
[228] Dr. Hughlings Jackson has quite recently cited some curious examples in his own practice. See West Riding Lunatic Asylum Reports for 1875.
[229] Problems, Vol. II. p. 478, sq.
[230] “Le sentiment fait naître le mouvement, et le mouvement donne naissance au sentiment.”—Van Deen, Traités et Découvertes sur la Moëlle Épinière, 1841, p. 102.