An excerpt from the beginning of
CHAPTER I. GENERAL PRINCIPLES.
It is not difficult to understand the reluctance of scientific investigators to indulge in theories connected with the brain which are not supported by rigidly authenticated evidence. No state of knowledge can be anticipated which furnishes a key to the complicated processes of the mind. Scientific research, however, has opened up the vast field of the functions of the brain, and while there are innumerable points of minute detail yet to be settled, along with others which are bound to arise, the broad facts concerning the sensory and motor functions are not in dispute.
We need not discuss whether these functions are localized in definite areas, or are inherent in groups of cells closely related to one another: it must, however, be emphasized at the outset that no grounds exist for identifying the manifold operations of the mind with special cerebral tracts. In other words, the higher brain centres concerned with the will, the emotions, and all the varieties of creative activity, are not as yet capable of definite localization.
At the same time, we may quite reasonably desire that those mental processes which are not primarily to be assigned to sensory or motor centres should be classed under one term to describe them and convey a clear meaning as to the operations with which they are concerned. For although all ultimately are referable to some group of these centres by minute analysis, we are still at a loss for a word-a "short title," in fact-to describe the impulses of the mind which belong properly to the creative faculty, and which arise without apparent external stimulus. Bastian1 suggested "Perceptive Centres," but these cannot be isolated from the sensori-motor tract.show more