PRESENTATION AND REPRESENTATION. 59 images and ideas are copies of sensational impressions arose in the minds of the early observers of psychic states as such ; nor is it surprising that this notion which had come to them 'rom their predecessors, became fixed in the minds of the
- arlier psychologists who knew little of the nature of the
nervous system and of the psychic correspondences with which we are so familiar ; but it seems to the writer to be ar from creditable to the masters of our own time, with heir wider knowledge, that they still cling to this notion, plicitly if not explicitly, as they do. The naive observer cannot fail to notice certain cases where the psychic correspondents of direct impressions upon is body from without seem almost identical with psychic itates which are clearly not correspondent with such direct mpressions. If in one moment he experiences the vivid pression due to his looking at the sun, and in a second oment closes his eyes, his experience in the second moment ill usually be what Fechner would have called a "memory- after-image" of the sun, or what modern psychologists 1 are wont to call a "primary-memory-image," which is evidently very like the psychic correspondent of the impression when his eyes were open. For the sake of simplicity we pass over with a mere .ention the fact that he occasionally notices what we call ositive or negative " after-images " ; these, when he notes ,hem, are evidently closely related to the " primary-memory- images " just mentioned. Now the immediately subsequent thoughts, as he calls them, of these "primary-memory-images" are presentations which are evidently closely allied with the original " primary- memory-images " which seemed when he experienced them to be so nearly identical with the original vivid impressions. But such a " thought " is a presentation which he is wont to speak of as an " idea " rather than as an image ; and when a similar thought recurs the next day it is clearly a very ordinary kind of " idea," yet is looked upon as practically the same as the " idea " of the day before, which was so closely connected with the original presentation coincident with an impression upon him from without that he then called it an image or copy of this original presentation. While these considerations serve to explain how it happens that the na'ive psychologist is led to think of what we call images and ideas as in a sense copies of original impressions, they also show that we ought not to content ourselves with 1 Cf. Ward, op. cit., p. 59 ; James Sully, Human Mind, i., 279.
