Now what happens if the person becoming a homeopath- and one should always remain in the becoming stage- must work out his materia medica from the several elaborations for himself? We do not possess a single text-book that would satisfy all demands of physicians of the present time. This is due to the fact that only a very few of the number of homoeopathic physicians, a number small in itself, have ventured such a work, a labor which each generation must take up again anew. But then it also lies in the special difficulties of this task. School medicine is not much better off in materia medica although there the circumstances are much more favorable. There, clinical experience have more than one hundred times as much soil and experimental pharmacology adds its objective easily provable single reports in masses. But there too is nothing uniform empiricism and experimental pharmacology, no modern materia medica develops. For one would hardly hold the compilations of encyclopedias as such. In general, empiricism and experimental data stand uncombined beside one another.


The real difficulties in a homoeopathic materia medica lie in another place. First: How shall one sift the symptom register? Here one can actually speak of the fight of manifestation. Because the numerous, mostly subjective symptoms are variable manifestations difficult to fix. Which of them should one consider and accept as effects of doses of drugs and which be blotted out as independent transient manifestations of the eternally changing events of life? A responsible beginning, enlightened only by the certainty that the original symptom register or protocol still exists for the better adaptor. What are the criteria for this sifting? Most enlightening at first seems the statistical criterium: the more frequent a symptom has appeared in the proving of a drug, so much more surely does it belong to the field of action of this drug. This numerical conception is simple, but for our task, the working out of an effect picture typical for one drug, it is too primitive. The one-sided statistical treatment of our crude material would only lead to a sad torso. The reason for this is as follows: primarily that symptom is most frequent which is designated by the most general expression, as perhaps headache. And we can use this the least on account of its generality, that is because it is common to innumerable medicinal substances. Here the certainty opposes the value. Secondly, this statistical procedure confers an unjustified preponderance upon the inexact average mass observation. It is exactly the desired individual X which is omitted in mass equations. And drug proving in the homoeopathic sense is never a mass investigation but a study in precision in single suitable persons. By the precision certainty is also obtained but it need not be secured at the cost of the individual qualities, particularly in the assemblage of properties of the drug and person. The same defect is intrinsic to symptoms obtained by force through large doses in all or almost all men. What they gain in surety through their frequency, they lose in specificity and therefore in differential therapeutic value.

The obtainment of a surety index numerically has only a very limited value in the work of sifting. An agent may provoke headache or nausea or renal inflammation with great constancy (in which one takes into consideration that a definite effect is not favored by the type of injection), still these great aims can serve with the corresponding surety index only for the classification of the required finer symptomatics. But it is not true that an effect direction of high surety index must necessarily also be especially useful therapeutically. How far it may, depends much more upon whether the specifications through characteristic, individual, leading symptoms are possible within this crudely outlined domain of action. There should be active functional early symptoms which reveal a lively defense activity: then the outlook for a stimulation therapy will be favored in the determined general direction of effect.

But what certainty have we that these fine individual symptoms belong to the picture of the drug? There is first that they have an unusual, striking character for the observer. Unfortunately, we do not always find this sufficiently stressed in the old provings so that a supplementary evaluation is difficult. Consequently, one next refers to the frequent repetition of such a symptom and if it is only in one prover who naturally must be of the type that the connection with the administration of the drug has a certain probability. From a statistical viewpoint we must be contented with assigning an essentially lower grade of surety to these symptoms.

But we have still another criterion for the acceptance of differentiating rare symptoms from the protocol of the drug picture. There is the possibility that these observations of details if it into effect associations determined in some other way. These general associations of drug picture can be determined; (1) through the remaining symptoms of proving, (2) through the major trends of effect, as at times from animal experimentation and at times from poisonings in man and already known materials from the physiology when they normally occur in the organism. But we must avoid the replacement of the subtle observations by the crude. The viewpoint of classification can and need not suppress the specific content. The specific symptoms must be retained in their originality and immediateness. The viewpoint that symptoms are accepted when comprehensible through some other connection, also need not be decided onesidedly. Symptoms which elsewise have probability (perhaps special striking character.) but fail to comply with any connection, must remain separate conditionally. Because the recognition of the connection is also temporally conditioned. Perhaps in the future one will understand it in its connections.

After what has been said, will animal experimentation, the experimental pharmacology, be of significance for the shaping of homoeopathic materia medica? Certainly! We will not neglect any kind of factual knowledge which can bring clarity into the connection of a medicinal substance to the living organism. We will also use the relations of medicinal substances inanimate to material, also physical chemistry, where it belongs, namely, where it can contribute to explanation and to the understanding of complicated actions. None of the results of investigation will be intentionally neglected by us whether it is of the action of a substance on a single cell, the single organ, or the organism. We shall not permit ourselves to become confused by the foolish objection that these investigations have not grown on homoeopathic soils, that Homeopathy has contributed too little to this type of investigation. Actually there is only one science, but none should believe that they alone have all options. The task of homoeopathy was and is to nourish another branch of materia medica which is neglected by all others because they have not seen the profits for therapy. It all comes merely to how the results from the various fields of research are to be evaluated, on what mental site they stand and how they are arranged to a totality. Since this totality, the drug effect picture, should serve only a practical aim, the therapy, so it is self-understood that we place the greatest weight on the data opiating to us to be most suitable for it. And these are the characteristic pointed accomplishments of a medicinal substance obtained from the investigation of man. Further, it is well understood; each in its own place.

If it is concerned with a different substance which easily gives occasion to poisoning, then we will perceive toxicologic experiences as the massive structure on which is raised the more blurred architecture rather than the sketch in which the picture is filled in with single details. The more chronic the picture of poisoning the more it approaches the international drug proving in details and therefore its utility for our purpose. On the country, from the stormy intoxications we do not derive much, not even for the arrangement of symptoms. The toxicologic animal experiment accomplishes little for our intention on the one side because it excludes the possibilities of human reaction from the start. But, on the other side, it provides more in explanation, deductions to systems of lower order because these observations can be systematically arranged with various but previously determined conditions and repeated with approximate accuracy. There one can go back from organism to single organs, from organ to cell, form cell to its ferment, to its energy and salt resources and thereby to physicochemical processes.

If it is concerned with a medicinal substance which normally appears in the organism so we can utilize all that is known to us of its physiologic role. This serves for explanation and classification of the data which we have obtained from drug investigations on man. The question of how such physiologic materials in general cause symptoms and correspondingly can have healing effects can be mentioned here only briefly. Necessary for this are, not too excessive amounts of the substance, but alterations in the matter of division, in the place of applications, and the administration and frequent repetition can also be of significance here. To this naturally must come on the other side a special sensitivity of the prover. An extreme example of such sensitivity to substance normal to the body is the iodine sensitivity in hyperthyroidism.

We have proceeded from the sifting of the symptom register and found at the same time that an arrangement is found in which all available knowledge on the action of a medicinal substance in general must be included. The correctness of single drug pictures will also depend upon the available factual material, its intellectual and comprehensible presentation in the control of these facts and understanding of order. The actual observations always must be separated from explanations.

Among the observations the accents must be correctly placed according to the merit for therapy. Among the attempts at explanation, theories and hypotheses must be separated according to the extent of facts through which they are mentally deduced and arranged.


One important criterion for the sifting of materia medica we have set aside; this is therapeutic testimony. Indeed, we have said in general that the symptom especially valuable for therapy must receive a special accentuation. But this is meant only theoretically to a certain extent, of especially characteristic symptoms. In the ideal the therapeutic confirmation for each materia medica is decisive, because this doctrine treats of drugs and they should help. But in the rough actuality the accomplishment of this criterion is not ideal. For therapeutic experience is an uncertain field. On the one side subterfuges can be found for each absence of an expected healing action, on the other side, each favorable action can be doubted and questioned. Only the frequent concurrence with prognosis yields some surety. Indeed, the materia medica should be such that it underlies and enlightens the prognosis, its value depending upon the grade of probability of the prognosis. Each therapeutic confirmation of a statement of the materia medica signifies therefore to a certain extent an underlining of this report, even if this report now is concerned with a very general conception as rheumatism or differential characteristic as tearing pains, worse from rest; only the profit in confirmation of differential reports, as they are designated in homoeopathic materia medica, is even greater for the future utilization of a drug. Because the prognosis gains in value through the precision with which it can be made. For the homoeopathic materia medica the testing according to unchanging fundamentals for a century, even if not always with satisfactory criteria, accomplishes much in the sifting of symptoms but still is entirely insufficient. A testing in greatest extent, naturally with exact use of method and good knowledge of the existing materia medica, is urgently desirable. This must be left to time. In the meantime one can use this criterion of confirmation only according to the measure of personal experience and critical evaluation of reports in the literature for the purpose of sifting. Such a selection is indeed quite involuntary since that which is confirmed by personal experience is more impressive and better retained.

For homoeopathy in general each therapeutic confirmation of reports which have been gained by drug proving on the healthy, is beyond this, a confirmation of its methodic presumption, the simile rule.

But the therapeutic confirmation has significance not only for the sifting but also for the proper arrangement of symptoms. Because when an unclear report of the materia medica is confirmed, then from the connection in which the comparative symptom stands within the morbid picture, light can be thrown back upon the medicinal symptom. For example, if an absurd sounding symptom as sticking under the skin of the sole of the foot as if by needles of ice often serves as a helpful indication for agaricus in organic diseases of the central nervous system, then one is clearer about its connections.


Practice, the therapeutic experience, moreover also goes beyond a sifting and arrangement of reports in the homoeopathic materia medica. It adds new reports. Empirically proven drugs with undefined limits were indeed the original possession with which Hahnemann also began his refining work. Because in every materia medica it is concerned with a precision of the primary crude material. So in homoeopathy there are also single remedies with only an empiric basis and which have not been generally or sufficiently proven on the healthy. There were and are employed, as in the old school, in the absence of better knowledge on general organ specificity or even on a diagnosis of a disease. I recall in this connection for example, solidago virgaurea as a renal drug, sabal serrulata as a prostatic remedy, which has proven itself as such. With others the proving on the healthy has been made more recently as for example that of crataegus oxycantha recently by Assmann, and it is interesting that the empiric use has found supplementary support in the symptoms of provings.

Again, in other agents proven on the healthy, often such symptoms or syndromes are accepted newly in a drug picture which have affected exactly such patients as are cured by this agent. To the so-called pure materia medica such reports as observations on patients do not belong. But in the difficulty of working out the individual characteristics of a drug picture one must put up with these additions in the meantime but use the proper caution. Still these supplementing in-corporations of observations on cured patients are justified up to a certain extent. Because if one can actually say: this or that agent has had the best healing effect in thin, blond sensitive persons, then we say practically the same as if we proceed from the basis of a study upon the healthy; thin, blond sensitive persons react most markedly to this agent. Because we see the curative action of a remedy also as a reaction of indeterminate sensitivity. However, one should remain conscious of the origin of all purely clinically derived addition symptoms.


It should be very clear that the homoeopathic materia medica is not rigid or finished. And the knowledge of single medicinal substances, whose working domain is de facto very different, is also in varying stages. In the one drug as perhaps crataegus, the emphasis lies still on the empiric organ specific side; in another, as perhaps sulphur, is the elaboration of the drug picture characteristic of homoeopathy preponderant. In the presentation these differences must come distinctly to expression, each drug picture must be conceived and represented as possessing a special individuality in itself. But the student in many cases again desires another selection or another emphasis: to one from the beginning the clinical or the organ specific reports are retained, for another the importance lies more in the subtle delineating detail symptoms. For each method of consideration there is available room in homoeopathic materia medica in the various elaborations. The inconceivably great difficulties of this study will only interest those who are profoundly convinced of the meaning of this homoeopathic materia medica in theoretic and practical respects.

Otto Leeser
Otto Leeser 1888 – 1964 MD, PHd was a German Jewish homeopath who had to leave Germany due to Nazi persecution during World War II, and he escaped to England via Holland.
Leeser, a Consultant Physician at the Stuttgart Homeopathic Hospital and a member of the German Central Society of Homeopathic Physicians, fled Germany in 1933 after being expelled by the German Medical Association. In England Otto Leeser joined the staff of the Royal London Homeopathic Hospital. He returned to Germany in the 1950s to run the Robert Bosch Homeopathic Hospital in Stuttgart, but died shortly after.
Otto Leeser wrote Textbook of Homeopathic Materia Medica, Leesers Lehrbuch der Homöopathie, Actionsand Medicinal use of Snake Venoms, Solanaceae, The Contribution of Homeopathy to the Development of Medicine, Homeopathy and chemotherapy, and many articles submitted to The British Homeopathic Journal,