The elements of experience and their integration, or modalism / by Henry J. Watt.

  • Henry J. Watt
Date:
1911
Catalogue details

Licence: In copyright

Credit: The elements of experience and their integration, or modalism / by Henry J. Watt. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    90/96 (page 301)
    (11) “ It seems that the owl, the frog, the chameleon, and other beasts of prey enjoy binocular vision in spite of the fact that in them the decussation of the optic nerves at the chiasma is complete.” (12) “The hypothesis of the ‘common centre’ is founded upon a radical misconception of the conditions of fusion of effects of sensory stimuli ”—viz. “ That the sensation evoked by the stimulation of any sensory point or nerve-fibre comes into existence as an isolated or detached fragment of psychical existence, and that such fragments become compounded to form a consciousness” only in virtue of a corresponding fusion of subservient nervous conditions. The true statement may be formulated in the following way : “ In so far as sensory stimuli affect con- sciousness, they produce partial modifications of the complex but unitary whole of consciousness; and when several stimuli simultaneously affect consciousness, their effects in consciousness can only be discriminated from one another in so far as there obtains some special ground of distinction. Such special grounds are of two principal classes—namely differences of quality and differences of local signature of the several sensory effects of sensations, as we commonly call them ; and the power of distinguishing...sensation-elements by aid of either of these grounds of distinction depends largely upon previous practice in active dis- crimination.” “ When the effects of two or more sense-stimuli appear in consciousness combined to a common resultant, this is because the separate cerebral processes act upon this one being [call it the soul or what you will] and stimulate it to react according to the laws of its own nature with the production of changes in the stream of consciousness1.” I think we may agree that these arguments are decisive against any view that holds that the excitations from the two retinae impinge upon a unitary, common, centre—a sort of blob of undifferentiated jelly—and are there simply and entirely summated, merged or wrought into one another, as two drops of water that run together. But this view hardly needs such heavy condemnation. For if the unity of the individual consciousness does not involve a punctate cerebral seat for the soul—as the failure to find one seems to show,—neither should the lesser unities of consciousness necessarily imply the existence of corresponding punctate centres. Besides, it is obvious that the existence of such punctate centres of fusion would be the very strongest evidence against parallelism. Even if we suppose that in the common centre the two contributory excitations were merely superimposed without summation, such a centre would be useless, because it would offer no physical correlate to binocular stereoscopic vision. The neural basis of binocular vision is undoubtedly much more complex than has been often rashly supposed. But having established that the two eyes are in certain respects functionally independent, in others functionally equivalent in spite Op. cit. 298.