Only the most careful examinations of the previous life of the patient, the investigation of childish tendencies and habits at school, and the incidents of boyhood and youth will sometimes enable the expert to recognise the constant existence of symptoms of mental disequilibration, the decided manifestation of which leads to serious events in after life. Monomania as a defense for crime has brought expert evidence into great disrepute. In this matter the greatest care is undoubtedly needed, however, for it is easy to do great wrong and punish the irresponsible victim of an impulse over which he has no proper control. On the other hand, it must not be forgotten that no such thing is known to exist as the perversion of the will on a single point. Moral insanity with regard to one special set of actions is a delusion that the {301} increase of knowledge with regard to mental diseases has erased from the text books on this subject. _Responsibility of Paranoiacs_.--From what has been said it is easy to understand how difficult is the determination of the responsibility of paranoiacs. Many classes of persons ordinarily considered to be quite responsible for their actions are yet so circumstanced that they are led into the performance of actions usually not considered rational, though not tempted thereto by any benefit directly accruing to themselves. On the contrary, it not infrequently happens that the mode of life adopted by the paranoiacs is of such a kind as would of itself, because of the hardships involved or the mental trials, deter ordinary people from following it. Paranoia, at least in its severer forms, completely justifies the plea of irresponsibility for actions committed. When it is remembered, however, that paranoiacs are often cunning enough to take advantage of their own supposed queerness voluntarily to commit crimes they might otherwise be deterred from by fear of punishment, some idea of the difficulty of the decision in these cases may be appreciated. It is important, of course, that the physician should, as far as possible, avoid falling into the error of judging such people too harshly, since after all on him depends the attitude of society towards them. It would seem to be quite as important that the clergyman should occupy an advanced position in this matter. It might seem that charity could easily be overdone; it must never be forgotten, however, that it is better that ninety-nine guilty should escape rather than that one innocent person should be punished.