Insanity is a common condition, but it has not been satisfactorily defined. It supposes an appreciable unsoundness of the will, memory, and understanding, or of one or two of these faculties, but no alienist has given a short differentiation of that unsoundness. Where shall we draw the line between the weak but responsible will and the insane will? What degree of opacity between intellect and the world separates the ignorant man from the lunatic? The extremes of sanity and insanity are readily recognisable, but the intermediate degrees are not clear. There is no test to apply to all cases; each must be diagnosed from its peculiar symptoms, but the will of an insane man is always weak. It can not deny or defer the gratification of a desire, nor can it keep up an effort. Even in its lightest forms insanity is selfish and {107} impolite, because it lacks the force of will necessary to take trouble. It foregoes great future benefit for slight present gratification. The insane man is idle, or busy only in work that he likes, in pleasurable activity. A marked quality of sanity is the capacity for sustained work, and the man that shirks work merely because he does not like it is gratifying himself dangerously. These defects are found commonly in sane persons, but the lunatic can not rise from them, and he adds to the defects of will a warped intellect. He can not adjust himself to his surroundings, and the fault is in himself, not in the circumstances. His intellect may be brilliant, but it sooner or later shows a taint. The insane man is not a free, rational agent. Alcoholism readily passes over into unmistakable insanity, and it almost always is the cause of nervous degeneration in the children born within its influence. This, is a phase of the evil not sufficiently insisted upon by those that plead for total abstinence.