In concluding this chapter I remark, that the subject of it demands of medical men a more distinct and thorough attention than it commonly receives. The physician should be something more than a _mere doser of the body_. Mental influences are among the most important of our appliances in the cure of disease. The physician, therefore, in fulfilling his high vocation, should not only have a full knowledge of mental philosophy, but he should aim to acquire a practical skill in applying its principles to all the ever varying phases, which the mind presents in its connection with disease. The possession of this skill is one of the most valuable endowments of the medical art. FOOTNOTES: [38] This chapter, and the chapter on _Truth in our Intercourse with the Sick_, appeared some years since in the New Englander. [39] It is often difficult to determine definitely what are the real sentiments of phrenologists on this subject. But that some of them, if not actually and fully materialists, are very near it, there is no sort of doubt, if language is to be understood as used by them in the same way that it ordinarily is. They not only strip man of all the elements of moral character, and consider him, as one of them expresses it, as ‘a bundle of instincts,’ thus making him but a brute of a higher order; but the material organization is exalted in their view above all those spiritual qualities or powers, which they seem to consider either as attached to it, or resulting from it, or at least as being in no sense independent of it. If this be not materialism, it comes very near to it. CHAPTER XV. INSANITY. It is not the object of this chapter to treat at large of insanity. It is my intention to speak, as briefly as possible, of some points in regard to its causes and its treatment, which ought to be understood by the community. The causes of insanity may be divided into two classes—those which act upon the mind, and those which act upon the body. The mental causes of insanity do not produce the disease directly through their influence upon the mind. But this influence extends to the organization with which the mind is connected; and the insane manifestations or symptoms are entirely the result of the reaction of the affected organization upon the mind. As this point has been somewhat fully elucidated in the chapter on _the Mutual Influence of Mind and Body in Disease_, it is not necessary to dwell upon it here. The physical causes of insanity may be subdivided into three classes; those which act upon the great central organ of the mind, the brain; those which produce disease in other organs, affecting the brain sympathetically; and those which have a more general influence upon the system as a whole, or as a congeries of organs. In an individual predisposed to insanity by the peculiar cast of his nervous system, this malady may be induced by some local disease of some of the organs, or by an impaired state of the general health.