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.
These are common to all drugs and appear in every proving. They can practically be eliminated. Such are symptoms like feeling of malaise, loss of appetite, weakness, distress, headache, etc. Such general symptoms, unless amplified by accompanying conditions or modalities, are of comparatively little value for the prescriber, because their presence does not point clearly to any one particular drug. We must find in our symptomatology, and make use of such symptoms as serve to individualize and give character to a drug, and hence these are called Characteristic Symptoms
Each drug is an entity, and can express its disease producing properties, i. e., pathogenetic force, in a way peculiar to itself. Those symptoms that do this most perfectly are the drug's characteristic symptoms. The ideal characteristic symptom is one which is possessed by no other than the individual drug of which it is predicated and to which it gives character as an individual. We learn to distinguish drugs very much as we learn to distinguish men, not by their general features, which are common to all, but rather by the peculiar expression and shape and habits by which we recognize the individual. It may be a small and insignificant thing and yet one that is most expressive of the person's individuality. So in drugs it is not the general effect upon the stomach or bowels or the general debility produced that serve to characterize it as the remedy, but rather the peculiar, characteristic uncommon, prominent symptoms.
These have also been designated as keynote * symptoms, by Dr. Guernsey, and as guiding symptoms, by Dr. Hering.
From a physiological point of view they may appear trivial and unimportant, but for purposes of prescribing they are paramount in importance. These characteristic symptoms of drugs may be found in one of three divisions of its pathogenesis.
* "While the keynotes, according to Dr. Guernsey, will, in each instance, form an unfailing guide, the requisite conditions and corresponding totality of the symptoms in such cases being inevitably present. If this doctrine is true - and in practice it has been confirmed by much experience - it is so because these so-called keynotes essentially represent a profound dyscrasia of the organic nervous system; either in such sensations of pain as precede even the first functional derangements, and are intended as premonitory admonitions; or in such sensations as arise in connection with, and in consequence of, the initial disorder in these most interior organs of vegetative life". - J. H. P. Frost in Hahnemannian Monthly, Vol. II, page 443.
1. In the locality or tissue or organ affected.
2. In the sensations.
3. In the modalities and concomitants.
These are the three grand divisions around which the symptomatology of drugs can be grouped, or into which they can be divided for practical study.