Suicidal insanity is probably the most common form of instinctive monomania. The force, or even presence, of the suicidal impulse is largely dependent upon the general tone of the system. The suicidal idea is common; it occurs to the minds of a vast number of sane people at one time or another under adverse circumstances. Hysterical women talk a lot of nonsense on the subject. Self-destruction due to {147} self-depreciation, weariness of life, and general gloom is not uncommon in the insane temperament. It is also a refuge to proud and sensitive people who have sacrificed their honor. But this is quite different from suicidal insanity, in which the impulse is often strongest at a time when there are the most reasons for living and the greatest happiness in life if the tormenting demon urging to self-murder could be excluded. Such people finally kill themselves, in spite of their best resolutions and efforts to the contrary, if the various faculties of the mind become more and more involved as the disease goes on and the power of self-control is progressively weakened. More general insanity of the degenerative type is sometimes developed from suicidal insanity. Homicidal insanity is fortunately still rarer than the last-mentioned form, although motiveless homicidal ideas occur to husbands and wives and parents with reference to those dearest to them, under conditions of prolonged mental strain or exhaustion, during pregnancy and the puerperal state, and at the climacterium. In suspected crimes the evidence of homicidal insanity should be clear and should rest upon the general signs of the degenerative mental state. Homicidal impulses are common enough among the insane. Just as there are persons who do not dare to have sharp instruments in their rooms for fear of killing themselves, so there are others to whose minds axes, knives, and razors suggest imperative conceptions of plans for killing another. It is difficult in either case for the physician to satisfy himself at what point real insanity begins. Seclusion under the morbid influences of an asylum is very bad treatment for the individual, and symptoms which seem very serious often disappear by restoring the general health. In a recent case,[16] where a youth of nineteen was acquitted of the murder of his mother on the ground of homicidal insanity, he knew that the act was wrong, realized that he had committed a crime, and was full of grief for it, as occurs in all such cases. It is the rule, too, that there is some condition of mental defect or degeneration out of which the homicidal insanity is developed. [Footnote 16: _Quarterly Journal of Mental Science_, October, 1883, p. 387.]