of logical argument; cannot realize the absurdity or
impossibility of error. He clings to his own beliefs, for the evidence
of his perverted senses or the deductions from his disease-irritation
are very real to him. When we find this to be the fact we know he is
insane.

Yet we must not confound delirium of fever with insanity. A patient
suffering from typhoid fever may have a delusion that there is a pail
by his bed into which he persists in throwing articles. Or he may have
the hallucination that he is being called into the next room, and try
to obey the supposed voice.

Certain delusions are commonly found in certain types of insanity.
Depressed patients frequently manifest the delusion that they have
committed a great sin, and are unfit to associate with anyone.
Excited and maniacal patients often believe they are important
personages--kings or queens, old historical celebrities, etc.
Paranoiacs commonly have delusions of persecution and of a conspiracy
among their relatives or their associates or rivals. Victims of
alcoholic insanity have delusions regarding sexual matters, and
generally charge with infidelity those to whom they are married.
General paretics in most cases have delusions of grandeur; that is,
false ideas of great strength, wealth, political power, beauty, etc.

The emotion which accompanies mental activity is generally exaggerated
in all insane people except the demented. One sees extreme depression,
or undue elation and exaltation, or silly glee and absurd joy.
Intensity of emotion is frequent.

_Crimes Impulsively Committed by the Insane_

An interesting mental feature of many insane patients is the
imperative conception, or imperative impulse. This is a strong urging
felt by the patient to commit a certain act. He may know the act is
wrong and dread the punishment which he expects will follow its
commission. But so constantly and strongly is he impelled that he
finally yields and commits the act. Crimes are thus perpetrated by the
insane, with a full knowledge of their enormity. The fact that such
impulses undoubtedly exist should modify the common test, as to an
insane person's responsibility before the law. The statute in many
countries regards an insane criminal as responsible for his act, if he
knows the difference between right and wrong. This decision is unjust
and the basis is wrong; for an impulse may be overwhelming, and the
patient utterly helpless during its continuance. Howeve