The first evil is the effect upon the mind through the brain and nervous system from evil communications or evil literature. The mind is thus prematurely awakened to take in and dwell upon a series of impressions which awaken precocious sexual instinct. This precocity gives an undue and even dominating power to this instinct over the other human faculties. Coming into play before reason is strengthened or the sense of responsibility awakened, there is no counterpoise or principle of guidance to the rapidly developing powers of procreation. Thus the precocious stimulus of childhood, even if it has not undermined the individual health, becomes a direct preparation for the selfishness of lust in the adult. The other grave danger incurred by the practice of masturbation is the risk of its becoming an over-mastering habit, from the ease with which it can be indulged; also from the insidious and increasing power of the temptation when yielded to, and from its association with the times when the individual is alone, and particularly the quiet hours of the night. In the adult who yields to solitary vice, Nature’s marked distinction between the beneficent effect of spontaneous healthy relief and the injurious action of self-induced irritation is destroyed. Individual self-control, the highest distinctive mark of the human being, is abandoned. In this way the evil habit may become a real obsession, leading to destruction of mental and physical health, to insanity, or to suicide. It will thus be seen that this first abuse of the sexual faculty given to us by our Creator--viz., the practice of masturbation--is a special danger to the very young as well as a temptation of the adult, and that it is an injury to mind as well as body, through the inseparable union of the moral and physical elements of our human constitution. CHAPTER IV _On the Abuses of Sex_--II. _Fornication_ The second abuse of sex to be dwelt on by the Christian physiologist is the practice of fornication. One broad distinction separates this form of vice from masturbation--viz., that it necessarily affects two persons instead of only one. Its effects upon the mental and physical development of both the male and female must therefore engage the attention of the physiologist. This necessity of considering the effects produced by a joint act upon two separate individualities greatly complicates the inquiry.