Page:Popular Science Monthly Volume 2.djvu/328

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muscles of the blood-vessels; such are the movements of the respiratory organs, etc. Again, there are a great number of cases in which the adaptation between the excitement and the act must have been originally regulated by conscious intelligence; but, the habit once acquired, the concurrence of intelligence has become useless. The player on a musical instrument needs at first to combine, by an act of his will, the movements of the fingers with the visual perception of the notes; but, after a sort of organic coexistence between these facts is established by repetition and practice, the one may become directly the cause of the other, without the concurrence of the power that regulated their adaptation; the movements of the hand then follow the impressions on the sight mechanically, while the intellect may be occupied with something quite different. Thus a machine, once constructed and regulated, has no need of the intelligent workman, who adjusted its cogs and wheels, to keep it going. If we pinch a frog after its brain is removed, it makes motions as though to repel the hand that hurts it; it is a reflex action resulting from habits contracted under the cerebral influence, and strongly enough established to survive the removal of the intellectual organs. After this we do not deny that a certain degree of intelligence may exist in other nervous centres besides the brain; we grant that they may have a peculiar consciousness of their modifications and their movements. But we go no further, and we refuse to follow Hartmann, as soon as his hypotheses needlessly take on a metaphysical or supernatural character.

Still less shall we follow him when, throwing himself into theories which remind us of those of Stahl, he insists that the organization of living bodies can be formed no otherwise than by the action of an intelligent but unconscious principle; that, in diseases, a regulating intelligence, a vis medicatrix naturæ, presides over the restoration of the functions to their normal state; that the reproduction of organs observed in some animals is caused by the unconscious idea of the usefulness of such organs, for the preservation of the individual; that in every part of the living being there resides an unconscious idea of the type of the species, which directs the reproduction of the organ removed, the reparation of tissues, etc. These facts, all having relation to the study of forms, types, or species, are exactly those which Darwin's theory best succeeds, as we think, in explaining. Hartmann, however, does not altogether reject the ideas of the great English naturalist; but he limits their application considerably, and interprets them in a manner quite contrary to their author's. He admits natural selection, indeed, in the struggle for existence; but this selection is not, in his view, a primordial fact, resulting from the force of things; he calls it simply one of the means that unconscious intelligence would employ in arriving at its ends. Besides, selection would be insufficient still, according to Hartmann, to account for the organic forms of the species, for what he calls the morphological facts, and ought to be ap-