The contrast between our attitudes toward crime and toward insanity is primarily a matter of personal idea and impulse. We understand the criminal act, or think we do, and we feel toward it resentment, or hostile sympathy; while we do not understand the insane act, and so do not resent it, but regard it with pity, curiosity, or disgust. If one man strikes down another to rob him, or in revenge, we can imagine the offender’s state of mind, his motive lives in our thought and is condemned by conscience precisely as if we thought of doing the act ourselves. Indeed, to understand an act _is_ to think of doing it ourselves. But, if it is done for no reason that we can comprehend, we do not imagine, do not get a personal impression of the case at all, but have to think of it as merely mechanical. It is the same sort of difference as that between a person who injures us accidentally and one who does it “on purpose.” Secondarily, it is a matter of expediency. We feel that the act which we can imagine ourselves doing ought to be punished, because we perceive by our own sympathy with it that more of this sort of thing is likely to take place if it is not put down. We want the house-breaker to be stigmatized, disgraced, and imprisoned, because we feel that, if this is not done, he and others will be encouraged to more housebreaking; but we feel only pity for the man who thinks he is Julius Cæsar, because we suppose there is nothing to be feared either from him or his example. This practical basis of the distinction expresses itself in the general, and I think justifiable, reluctance to apply the name and treatment of insanity to behavior which seems likely to be imitated. It is felt that whatever may be the mental state of the man who commits an act of violence or fraud, it is wholesome that people in general, who draw no fine distinctions, but judge others by themselves, should be taught by example that such conduct is followed by moral and legal penalties. On the other hand, when the behavior is so evidently remote from ordinary habits of thought that it can be a matter only of pity or curiosity, there is no occasion to do anything more than the good of the person affected seems to require.