It is, however, true that in each succeeding census a steadily increasing number and percentage of the deaths is attributed to diseases of the nervous system. This, however, does not yet exceed fifteen or twenty per cent of the whole, which would be, so to speak, the natural probable percentage of deaths due to failure of one of the five great systems of the body: the digestive, the respiratory, the circulatory, the glandular, the nervous. Two elements may certainly be counted upon as contributing in very large degree to this apparent increase. One is the enormous saving of life which has been accomplished by sanitation and medical progress during the first five years of life, infant mortality having been reduced in many instances fifty to sixty per cent, thus of course leaving a larger number of individuals to die later in life by the diseases especially of the blood-vessels, kidneys, and nervous system, which are most apt to occur after middle life. The other is the great increase in medical knowledge, resulting in the more accurate discovery of the causes of death, and a more correct reporting and classifying of the same. In short, a careful review of all the facts available to date leads us decidedly to the conclusion that the nervous system is the toughest and most resisting tissue of the body, and that its highest function, the mind, has the greatest stability of any of our bodily powers. Only one man in six dies of disease of the nervous system, as contrasted with nearly one in three from diseases of the lungs; and only one individual in four hundred becomes insane, as contrasted with from three to ten times that number whose digestive systems, whose locomotor apparatus, whose heart and blood-vessels become hopelessly deranged without actually killing them. CHAPTER XIX MENTAL INFLUENCE IN DISEASE, OR HOW THE MIND AFFECTS THE BODY One of the dearest delusions of man through all the ages has been that his body is under the control of his mind. Even if he didn't quite believe it in his heart of hearts, he has always wanted to. The reason is obvious. The one thing that he felt absolutely sure he could control was his own mind. If he couldn't control that, what could he control? Ergo, if man could control his mind and his mind could control his body, man is master of his fate. Unfortunately, almost in proportion as he becomes confident of one link in the chain he becomes doubtful of the other. Nowadays he has quite as many qualms of uncertainty as to whether he can control his mind as about the power of his mind over his body. By a strange paradox we are discovering that our most genuine and lasting control over our minds is to be obtained by modifying the conditions of our bodies, while the field in which we modify bodily conditions by mental influence is steadily shrinking.