The insane are out of harmony with their social environment, but not necessarily in opposition to it.
There is no very sharp line between insanity and criminality.

The criminal is in direct antagonism to the laws of social life.

An insane person may cause the same injury to society as a criminal, but his actions are not voluntary, whereas the criminal is one who can control his actions, but does not.

Mentally degenerated persons, however, can be both insane and criminal.

Whatever the state of society, this reprobates the actions of one opposed to it; in a society in which it were usual to appropriate the possessions of others or to devour unpleasant or useless relatives, virtue and lack of appetite would be reprobated as unsocial.
The symptoms of insanity or the manner in which the defective action of the brain expresses itself and the various underlying pathological changes vary, and by combining these it has been possible to subdivide insanity into a number of distinct forms.