ated, in some sort, from two different sides, from in front and from behind. From the front they receive impressions sent in by the sense-organs, and consequently by a real object; from behind they are subject, through successive intermediaries, to the influence of a virtual object. The centres of images, if these exist, can only be the organs that are exactly symmetrical with the organs of the senses in reference to the sensory centres. They are no more the depositories of pure memories, that is, of virtual objects, than the organs of the senses are depositories of real objects.
We would add that this is but a much abridged version of what may happen in reality. The various sensory aphasias are sufficient proof that the calling up of an auditory image is not a single act. Between the intention, which is what we call the pure memory, and the auditory memory-image properly so called, intermediate memories are commonly intercalated which must first have been realized as memory-images in more or less distant centres. It is, then, by successive degrees that the idea comes to embody itself in that particular image which is the verbal image. Thereby mental hearing may depend upon the integrity of the various centres and of the paths which lead to them. But these complications change nothing at the root of things. Whatever be the number and the nature of the intervening processes, we do not go from the perception
