Neither does physical knowledge of individual function reveal the developed use of which it is capable. The new life that may be given through touch to the blind, or the destruction of a nation through its vices, is not revealed by the minutest examination of the mechanism of touch, or the physical structure of the nervous system. Function and use are only proved by observation, reflection, and rational experiment patiently carried on age after age, with generalization based upon accurate and accumulated facts.
Structure, function, and extended use, although closely connected, are, nevertheless, separate branches of inquiry. Applied physiology comprehends them all. Function is the arrangement by means of which the independent life of the sentient being is carried on and maintained. Developed function or use includes the growth and improvement of the individual in relation to his fellows, and to existence outside his own personality.
No physiological truth is more firmly established than the fact that we can modify the action of our physical organs towards the special objects related to them, by the way in which we use our organs. By long-continued and careful study of the apparatus and processes of digestion, the physiologist has discovered the general plan by means of which food is converted into the substance of the body, and the part which each portion of the complicated digestive system takes in the maintenance of daily life. He does not stop, however, with this discovery of the general plan by which food is converted into flesh. He studies the way in which our habits of eating and drinking may destroy or improve the power of digestion, and recognises the effects which various kinds of food and drink may exercise upon the character of the individual and the race. The physiologist, therefore, proceeds to investigate, as a direct branch of necessary human physiological inquiry, the influence which the consumption of flesh or fruit, of alcohol or water, of warm or cold articles, of quantity or quality, etc., exerts upon the unique organization of the human being, in producing health or disease in mankind; or upon the power of self-control or endurance, with the promotion of ferocious or genial tendencies in Man. Both human strength and human character can be affected by enlarged knowledge and control of the uses which belong to the digestive system.
What is true of the effects of food is equally true of the effect of every other physical condition of human life. It is, therefore, a special work of the rational physiologist to discover the higher uses of our varied human faculties. We only see at present the beginning of this great work of applied physiology in enabling us to comprehend the full effects of food, air, exercise, climate, etc., upon human character. We possess only vague knowledge of the great facts of the hereditary transmission of diseased or healthy tendencies; and we give, as yet, no due consideration to the important results which follow from such transmission. We only faintly realize the transforming power of habit or mind in healthy growth and in morbid degeneration.
These investigations form a distinct branch of applied physiology; and such investigation and application of physiology is the especial duty of the rational or Christian physiologist who sees clearly that creative force is a beneficent power; and this perception cheers and guides him in the perplexed paths which lead towards human growth and perfection.
Medicine and morality being related to function and use are, therefore, inseparable in a Progressive State. The union between the physical, moral, and intellectual elements of our nature cannot be dissolved during lifetime. To speak of the ‘Physician of Nature’ and ‘Physician of Grace,’ as two entirely distinct classes is an untenable position or a misleading sophism. Sound education, State medicine, healthy society, must all be based upon the inseparable union of the various elements of the human constitution. This is the only rational system in a Progressive State; any other practice leads to empirical medicine and hypocritical morality.
The unity of human nature gives immense importance to the influences which surround the beginning of life and the education of the young. The greatest present obstacle to progress is the ignorance of parents, and above all of mothers, of many facts of physiology, and particularly of the facts of sexual physiology. For want of this knowledge our nurseries and schools are not wisely guarded, young people lack guidance, and marriages are too often the mischievous union of two unsuitable partners.
By the present lamentable ignorance of sound physiology, men and women lack the elements necessary for forming correct judgment on the most important relations of life. Parents are thus unequal to their first duty, viz., the guiding of domestic and social life, as helpmeets to one another.
In all the excellent treatises on physiology, domestic economy and education, prepared for the special instruction and help of parents and teachers, all knowledge is generally omitted which refers to the sexual functions; yet to the parent or educator this is an essential branch of knowledge. A woman attempts to carry on her work blindfold, who tries to educate her children, guide her household, or take her proper part in society without this knowledge. She understands nothing that is going on around her; she sees nothing but the surface of things; her influence is either stupid, mischievous, or negative, if she is not truthfully instructed in relation to the central force of human emotion and action.
Mothers, requiring this knowledge for their special duties which commence with infant life, can with propriety, purity, and reverence study the action and uses of our sexual powers. Their intense interest in the family and self-sacrificing devotion to its welfare, their insight into its needs, and their sensitive consciousness of the approach of danger to their offspring, make them the providentially appointed guardians of the young. The profound depth of the passion of maternity in women extends not only to the relations of marriage, but to all the weak or suffering wherever found. It gives a sacredness to the woman’s appreciation of sex, which has not yet been utilized for the improvement of the social life of the nation.