Certainly we cannot settle it by mere statistics. The norm never means merely a majority. Even if the overwhelmingly larger part of mankind suffered from phthisis, the few who were free from it would be recognized as well and all the others would be considered ill. In mental life still more, no one ought to propose that the exceptional function is the symptom of disease. The few persons who never had a dream in their lives differ much in their mental experience from the large majority and yet their peculiarity is certainly not a symptom which needs curative treatment. The only real test of health is the serviceableness to the needs of life. We have an unhealthy state of the personality before us wherever the equilibrium of the human functions is disturbed in a way which diminishes the chances of existence, and the seriousness of the ailment depends upon the degree of this diminishing power. Seen from a strictly psychological point of view, we must expect thus a broad borderland region between the entirely normal well-balanced mental life and that unbalanced disorder of functions which really interferes with the chance for self-protection and effectiveness. That the melancholic who declines to take any nourishment, or the paranoiac who misjudges his surroundings, is unable to secure by his own energies the safety of his life cannot be doubted. The balance is completely destroyed and the will and the intellect of the physician and of the nurse must be substituted for his own mental powers, if his life is to be prolonged at all. But the misjudgment and the depression of the insane are only an exaggeration of that which may occur in any man.