The following deductions may also fairly be made from observation: 

(1) That the present legal test for criminal responsibility is admittedly vague and inadequate, affording great opportunity for divergent expert testimony and a readily availed of excuse for the arbitrary and sentimental actions of juries, to which is largely due the distrust prevailing of the claim of insanity when interposed as a defence to crime.

(2) That expert medical testimony in such cases is largely discounted by the layman.

(3) That in no class of cases are the verdicts of jurors so apt to be influenced solely by emotion and prejudice, or to be guided less by the law as laid down by the court.

(4) That a new definition of criminal responsibility is necessary, based upon present knowledge of mental disease and its causes.

(5) Lastly, that, as whatever definition may be adopted will inevitably be difficult of application by an untutored lay jury, our procedure should be so amended that they may be relieved wherever possible of a task sufficiently difficult for even the most experienced and expert alienists.

A classification of the different forms of insanity, based upon its causes to which the case of any particular accused might be relegated, such as has recently been urged by a distinguished young neurologist, would not, with a few exceptions, assist us in determining his responsibility.  It would be easy to say then, as now, that lunatics or maniacs should not be held responsible for their acts, but we should be left where we are at present in regard to all those shadowy cases where the accused had insane, incomplete or imperfect knowledge of what he was doing.  It would be ridiculous, for example, to lay down a general rule that no person suffering from hysterical insanity should be punished for his acts.  Yet, even so, such a classification would instantly remedy that anachronism in our present law which refuses to recognize as irresponsible those born without power to control their emotions—­the psychopathic inferiors of science, and the real victims of dementia praecox.

Of course, if the insanity under which the defendant labors bears no relation to or connection with the deed for which he is on trial, there would logically be no reason why his insanity on other subjects should be any defence to his crime.  For example, there is the well-known case of the Harvard professor who was apparently sane on all other matters, yet believed himself to be possessed of glass legs.  Had this man in wanton anger struck and killed another, his “glass leg” delusion could not logically have availed him.  If, however, he had struck and killed one who he believed was going to shatter his legs it might have been important.  The illustration is clear enough, but its application probably involves a mistaken premise.  If he thought he had glass legs his mind was undoubtedly deranged—­whether enough or not enough to constitute him irresponsible or beyond the effect of penal discipline might be a difficult question.  The generally accepted doctrine is, that if a man has a delusion concerning something, which if actually existing as he believed it to be would be no excuse for his committing the criminal act, he is responsible and liable to punishment; but, as Bishop well says: