ing upon the examination of these two points, we will content ourselves with a very simple observation, which has indeed no novelty. In many people who are blind from birth the visual centres are intact; yet they live and die without having formed a single visual image. Such an image, therefore, cannot appear unless the external object has, once at least, played its part: it must, once at any rate, have been part and parcel with representation. Now this is what we claim and for the moment all that we require, for we are dealing here with pure perception, and not with perception complicated by memory. Reject then the share of memory, consider perception in its unmixed state, and you will be forced to recognize that there is no image without an object. But, from the moment that you thus posit the intra-cerebral processes besides the external object which causes them, we can clearly see how the image of that object is given with it and in it: how the image should arise from the cerebral movement we shall never understand.
When a lesion of the nerves or of the centres interrupts the passage of the nerve vibration,But an injury to the brain diminishes perception by lessening the appeal to activity. perception is to that extent diminished. Need we be surprised? The office of the nervous system is to utilize that vibration, to convert it into practical deeds, really or virtually accomplished. If, for one reason or another, the disturbance cannot pass along, it would be strange if the correspond-
