Illusions : a psychological study.

  • Sully, James, 1842-1923.
Date:
1905
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Licence: In copyright

Credit: Illusions : a psychological study. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    VISUAL AND OTHER PERCEPTION. So much it seemed needful to say about the mechanism of perception, in order to understand the slight disturbances of this mechanism that manifest themselves in sense-illusion. It may be added that our study of these illusions will help still further to elucidate the exact nature of perception. Normal mental life, as a whole, at once illustrates, and is illustrated by, abnormal. And while we need a rough provisional theory of accurate perception in order to explain illusory perception at all, the investigation of this latter cannot fail to verify and even render more complete the theory which it thus temporarily adopts. Illusions of Perception. With this brief psychological analysis of perception to help us, let us now pass to the consideration of the errors incident to the process, with a view to classify them according to their psychological nature and origin. And here there naturally arises the question, How shall we define an illusion of perception? When trying to fix the definition of illusion in general, I practically disposed of this question. Nevertheless, as the point appears to me to be of some importance, I shall reproduce and expand one or two of the con- siderations then brought forward. elements, should not gain a rough perception of an external order much more complete than our auditory perception, which is necessarily so fragmentary. This supposition appears, indeed, to be the necessary complement to the idea first broached, so far as I am aware, by Professor Croom Robertson, that to such animals, visual perception consists in a reference to a system of muscular feelings defined and bounded by strong olfactory sensations, rather than by tactual sen- Bations as in our case.