Imágenes de páginas








THE brain is the chief organ from which the force called the mind is evolved, and, so far as the present treatise is concerned, may be regarded as the only one. For, though, wherever there is gray nerve-tissue, whether it be in the brain, the spinal cord, or the sympathetic ganglia, nervous force is generated ; and, though all nervous force partakes more or less of the attributes of that which we call mind, its qualities, as exhibited by the force manifested by these latter two organs, are not of such a character, either in health or disease, as to come within the scope of the present treatise. It is with the mind developed by the brain that we have to concern ourselves.

By mind, therefore, I understand a force produced by nervous action, and in man especially by the action of the brain. There are animals without brains, and others again with the cerebral mass so small as to be of much less importance than the spinal cord, and yet in all these there are continual manifestations of the existence of mind. Indeed, in some of them the brain may be removed without, for a time, any considerable impairment of the mental force being produced. As we ascend, however, in the scale of animal life, the brain becomes more and more predominant, until, when we reach the higher orders, at the head of which stands man, it is almost the exclusive seat of the mind.

In former times the dependence of the mind upon the brain was not distinctly and fully recognized. The emotions, for instance, were supposed to have their seat in other organs

-some in the heart, others in the liver, the spleen, and the bowels. So firmly was this idea implanted that it even at the present day influences our modes of speech. Thus we say of a man that he has a “good heart,” or that his “heart is in the right place”; the boy learns his lessons “by heart," the lover adores his mistress with his “whole heart," and the sinner, when he is converted from his evil ways, undergoes a “change of heart." The influence ascribed to the liver is shown in our words “melancholic” and “choleric,” as applied to low-spirited and angry persons; to the spleen in the term “splenetic,” as indicating a spiteful individual; and we say of another that he has no “bowels of compassion.

The connection between the mind and the brain is not doubted at the present day, although the character of the relation is still the subject of controversy. On the one hand, it is contended that the brain is only a tool or organ of which the mind makes use in man to manifest itself. According to this view, there is in every human being a mind not dependent upon the nervous system for its existence. On the other hand, it is asserted that the mind is directly the result of nervous action, and especially of the brain, and that if there were no nerve-substance there would be no mind. This view is that which is held by the majority of scientific writers of the present day. The discussion of the question need not, however, concern us here, for, whether the one or the other theory be correct, the brain and nervous system generally must be equally the subject of study in the consideration of either normal or abnormal mental manifestations.

It may, however, be remarked that if the mind is in independent, self-conscious, immaterial personality, using the brain as its instrument for communicating with the external world, it is impossible for us to deny a like principle to the lower animals, differing only in degree as their brains differ from ours. They perceive, experience emotions, have intellects which memorize and exercise judgment, and wills to carry out, in accordance with their powers, the conclusions to which their reasoning leads them.

According to the theological school of philosophers, the mind of an idiot is as good as the mind of Herbert Spencer

« AnteriorContinuar »