This section is from the book "A Compend Of The Principles Of Homoeopathy", by William Boericke. Also available from Amazon: A Compend of the Principles of Homoeopathy as Taught by Hahnemann.
Hahnemann was a vitalist. His philosophical conceptions are a protest against materialism; against all merely chemico-physiological ideas, all pathological, bacterial, antitoxic theories, discoveries and facts as a basis for Therapeutics. He proves that a true science of therapeutics cannot be built on any such insecure foundations, and the whole history of medicine justifies the position. Again, his teachings in regard to disease and their cure by homoeopathic remedies require a practical acceptance of the existence of a vital principle animating the body, and at the same time a similar vital principle or force embodied in every medicinal substance. It necessitates therefore, a substantial world of causes, the world of mind where thought and affection, desire and lusts in their innumerable manifestations exist and a material world of effects, where these ultimate themselves in corresponding forms, and thus become fixed and enduring. Hahnemann saw in the body but an organism made up of material particles in themselves dead, but vivified and embodied and adapted to the real, living man, the spirit within. The connection between the immaterial, spiritual and immortal being, and the body is supposed by him to be effected by means of the vital force which he designates Dynamis. We have then, in Hahnemannian physiology, (1) the spirit, the true man, (2) the material body, receiving its life and health through (3) the vivifying vital force, the dynamis. From this conception follows the pathological deduction that the disturbance of the harmonious play of life, manifesting itself in symptoms affecting the functions and sensations which we call disease, is a disturbance of this same vital force or dynamis. This Dynamis differs from the material body in being of a more subtle quality and Hahnemann defines it, in contradiction of the material gross-ness of the body as "spirit-like". The vital force is active throughout the body, is the immediate cause of every functional activity, of all bodily growth. It is the formative force of the organism, is in fact the inner form which controls the molecular, chemical and mechanical processes, and uses them for its own purposes. Immaterial, hence beyond the penetration of the keenest sense or most powerful microscope, or the X ray. The vital force is the intermediate agent between the spirit and the body, enabling the spirit to dwell for a time in its material bodily clothing. Hahnemann's dynamis or vital force is not, therefore, the very seat of life, but only the connecting medium between the rational spirit, the true living man and the outer material covering by which man takes cognizance of this material world and its plane of external life. It is not necessary to suppose this vital force to be an organized entity, but rather the first ultimation on the plane of matter by means of the finest degrees of that plane, of the moulding, organizing and maintaining activity of the spirit within. If you choose to call it molecular motion, well and good, it is molecular motion guided for a definite end in view.
In disease, the vital principle is first disturbed, and its disturbance precedes functional and organic changes. Hence, disease is of dynamic origin, and the true causes of disease are such as affect the vital force; dynamic agents, mental conditions, passions, moral deteriorations in the individual or in the race. So-called causes of disease can act only as secondary causes when the vital force has become weakened in its resistance and allows untoward influences to affect the organism.
The following paragraphs in the Organon clearly teach this: 9, 10, 11, 12, 15, 16, 29.
"During health, the immaterial vital principle which animates the material body, rules absolutely. By it all its parts are maintained in admirable, harmonious vital operation, as regards both sensations and functions; so that our indwelling, rational spirit can freely employ this living, healthy instrument for the higher purposes of our existence".
"The material organism, without the vital force, is incapable of sensation, function or self-preservation; it is dead and subject only to the physical laws of the external world; it decays, and is again resolved into its chemical constituents; it is the immaterial, vital principle only, animating the material organism in health and disease, that imparts to it all sensation and enables it to perform its functions".
"In disease, it is only this immaterial, automatic vital force, pervading the entire organism, that is primarily deranged by the dynamic influence upon it of a morbific agent inimical to life. Only the vital principle, thus deranged, can furnish the organism its abnormal sensations and set up the irregular processes we call disease; for, as a power invisible in itself and only known by its effects on the organism, its morbid derangement only makes itself known by the manifestations of disease in the sensations and functions of those parts of the organism exposed to the senses of the observer and physician - that is, by morbid symptoms, and in no other way can it make itself known.
"How the vital force causes the organism to display morbid phenomena - that is, how it produces disease, - it would be of no practical utility to know, and, therefore, it will for ever remain concealed from the physician".
In the preface to the second volume of the "Materia Medica Pura," Hahnemann says: "Life is in no respect governed by any physical law which govern only inorganic substances. The material substances comprising the human organism are not governed in their living composition, by the same laws to which inorganic substances are subjected, but follow laws peculiar to their vitality; they themselves are animated and vivified, just as the whole organism is animated and vivified. * * * * As the organism, in its normal condition, depends only on the state of the vitality, it follows that the changed condition which we call disease or sickness must likewise depend, not on the operation of physical or chemical principles, but on originally vital sensations and actions - that is to say, a dynamically changed state of man - a changed existence, through which, eventually, the constituent parts of the body becomes altered in their character, as is rendered necessary in each individual case through the changed condition of the living organism".