Page:Philosophical Review Volume 1.djvu/498

482 observation extends, we have reason to believe that there are no "psychoses" (mental phenomena) without corresponding "neuroses" (organic phenomena). And yet it is impossible to translate any psychosis into any neurosis, or to say that this organic movement has become this phase of consciousness. Nor is it possible to say that this neurosis has produced that psychosis, as we may say that these two movements in space have combined to produce that movement in space. We evidently have here two orders of reality, one an order of consciousness-of-objects, the other an order of objects-of-consciousness. The problem of psychogenesis is, to trace the origin and development of this consciousness-of-objects.

Every known mental manifestation is associated with organic movement, and in man both mind and its expressive movements are centred in the cerebro-spinal portion of the nervous system, and especially in its encephalic ganglia, the brain. This complex and important organ has received within recent years the minute and prolonged attention of investigators both from an anatomical and a physiological point of view. Its topography has been carefully represented by means of accurate charts and models, its histological components have been examined by means of improved methods of section and coloration under microscopes of high power, its functions have been studied in the lower animals by every means at the disposal of science, and in man by post-mortem examination of sound and pathological cases as well as in lesions of the living. As a result of these investigations, a new and suggestive body of evidence is in existence regarding the localization of function. It is found that specific areas, more or less distinctly circumscribed, are specialized for motor and sensor functions, and that each sense has its own appropriate tract of stimulation. It is true that, as early geographers differ in their report of newly discovered countries, investigators in this newly explored territory vary in their results; still, there is a consensus on many important