_Not easily cured._--The condition now described is much less open to medical treatment than the mental states previously mentioned. Indeed, where there is insanity resulting from settled cerebral disorder, there is very little hope of cure. Nature may in time recover herself; she may not. This depends on age, constitution, predisposing causes, and a variety of circumstances not altogether under human control. _Disordered Action of the Sensibilities._--Another form of insanity is that which consists in, or arises from, not any primary disorder of the intellectual faculties, but a tendency to disordered _emotional_ excitement. Sometimes this is general, extending to all the emotions. These cases require careful treatment. The patient is like a child, and must be governed mildly and wisely, is open to argument and motives of self-control. In other cases, some one emotion is particularly the seat and centre of the disturbance, while the others are comparatively tranquil. In such cases the exaggerated emotion may prompt to some specific action, as suicide, or murder, etc. This is termed _impulsive_ insanity. The predominant idea or impulse tyrannizes over the mind, and, by a sort of irresistible fatality, drives it on to the commission of crime. The patient may be conscious of this impulse, and revolt from it with horror; there may be no pleasure or desire associated with the deed, but he is unable to resist. He is like a boat in the rapids of Niagara. So fearful the condition of man when reason is dethroned, and the will no longer master. MENTAL PHILOSOPHY. DIVISION SECOND THE SENSIBILITIES. PRELIMINARY TOPICS. CHAPTER I. NATURE, DIFFICULTY, AND IMPORTANCE OF THIS DEPARTMENT OF THE SCIENCE. _Previous Analysis._--In entering upon the investigation of a new department of our science, it may be well to recur, for a moment, to the analysis and classification of the powers of the mind which has been already given in the introduction to the present volume. The faculties of the mind were divided in that analysis, it will be remembered, into three grand departments, the Intellect, the Sensibilities, and the Will; the first comprising the various powers of _thinking_ and _knowing_, the second of _feeling_, the third of _willing_. The first of these main divisions has been already discussed in the preceding pages. Upon the second we now enter.