Two Similar Diseases – Aphorisms 43-46


Dr. Manish Bhatia analyzes and explains Hahnemann’s aphorisms 43-46.

Two Similar Diseases

Two similar diseases in homeopathyThe aphorisms 43 to 46 discuss what happens when two similar diseases meet in our body. In aphorism 43, Hahnemann just states that when two similar diseases meet in the body, the outcome is very different from the one which we observe when two dissimilar diseases meet in our body. He says that such cases show us how cures take place in nature and how we should employ medicines to cure.

§ 43

Totally different, however, is the result when two similar diseases meet together in the organism, that is to say, when to the disease already present a stronger similar one is added. In such cases we see how a cure can be affected by the operations of nature, and we get a lesson as to how man ought to cure.

As a side-note to this aphorism, I would like to bring your attention to the use of the word ‘disease’. Hahnemann repeatedly uses the word ‘disease’ instead of ‘sick’ or ‘sickness’. When I was in college, we were taught that we homeopaths (kind of arrogantly), do not treat ‘disease’, we treat the ‘dis-ease’ or the ‘person who has the disease’. This was so deeply ingrained in many young minds, that classical homeopaths are often ashamed to mention ‘disease’ and ‘pathology’ as part of their case analysis. I have said this before and I’ll repeat it again here – you cannot separate the disease and the ‘dis-ease’. They are part of one whole. The ‘pathology’ is also part of the ‘totality’. The mental and emotional portrait is important, but the tissue and organ affinity of remedies can also point towards the right remedy. Do not treat all mental and emotional symptoms as superior by default. Often the physical symptoms are far more characteristic and certain. Do not give Pulsatilla for every condition to a woman who has a mild and weeping disposition. Make sure that the presenting complaints, modalities and the causative etiology also match that of the Pulsatilla. Do not ignore the disease. Hahnemann did not!

Let’s come back to the aphorisms after this digression. In the next two aphorisms, Hahnemann shares what happens when two similar diseases meet in the body. He also gives many examples of natural cures to justify his observation. Let us read what he says:

§ 44

Similar diseases can neither (as is asserted of dissimilar disease in I) repel one another, nor (as has been shown of dissimilar disease in II) suspend one another, so that the old one shall return after the new one has run its course; and just as little can two similar disease (as has been demonstrated in III respecting dissimilar affections) exist beside each other in the same organism, or together form a double complex disease.

So Hahnemann first tells us what cannot happen when two similar disease meet in a body. He says that when two dissimilar diseases meet in a body they repel each other (if the former be stronger) or suspend each other (if later be stronger) or form a complex disease (if both have similar strength and different organ affinity). But when the similar diseases meet, none of this happens. Let us read in aphorism 45 what happens when two similar diseases meet in a body.

§ 45

No! Two diseases, differing, it is true, in kind1but very similar in their phenomena and effects and in the sufferings and symptoms they severally produce, invariably annihilate one another whenever they meet together in the organism; the stronger disease namely, annihilates the weaker, and that for this simple reason, because the stronger morbific power when it invades the system, by reason of its similarity of action involves precisely the same part of the organism that were previously affected by the weaker morbid irritation, which, consequently, can no longer act on these parts, but is extinguished2, or (in other words), the new similar but stronger morbific potency controls the feelings of the patient and hence the life principle on account of its peculiarity, can no longer feel the weaker similar which becomes extinguished – exists no longer – for it was never anything material, but a dynamic – spirit-like – (conceptual) affection. The life principle henceforth is affected only and this but temporarily by the new, similar but stronger morbific potency.

1Vide, supra, § 26, note.

2Just as the image of a lamp’s flame is rapidly overpowered and effaced from our retina by the stronger sunbeam impinging on the eye.

This aphorism is very vital because technically, the whole of homeopathy is based on this observation. So we need to closely examine this aphorism. Hahnemann basically says that when two similar diseases meet in a body, the stronger one will remove the weaker. The ‘when’, ‘how’ and ‘why’ of this, needs to be explored in detail.

Hahnemann lays down two conditions for the natural cure to take place:

  1. The two diseases have to be similar in phenomena

  2. They need to differ ‘in kind’

The phenomenon here refers to the pathological manifestation of a disease/infection. For e.g., the phenomena associated with Chickenpox are: Fever and eruptions on skin. Similarly, the phenomena associated with Measles are: fever and eruptions on skin. Now the eruptions on this skin are not ‘same’, but the broad phenomena do match. There is lot of similarity.

Differing in kind means that the basic nature/causative organism of the two diseases should be different. So while the phenomena of Chickenpox and Measles can be called similar, their pathological cause is very different. They are caused by two very different viruses. The difference seems to be essential. The difference ‘in kind’ is what separates Homeopathy from Isopathy. I have explained this difference ‘in kind’ in my lecture on aphorism 26 too, in relation to the role of Vital Force in cure. I request you to read it once more.

Before I move to explaining the mechanism of cure that Hahnemann has mention in this aphorism, here is a question for you? Are there any diseases that have ‘similar’ phenomenon but do not differ ‘in kind’? And what happens when such diseases meet in our body? Yes such diseases exist too. For e.g., the phenomenon of Hepatitis, A, B, C, D, and E is very similar but the cause does not ‘differ in kind’ significantly. They are all caused by viruses of the same family, which are very similar to each other. So you will often find various forms of Hepatitis occurring together. Such occurrence has not been explained in Organon anywhere and I feel it needs an aphorism of its own. We can call such simultaneous occurrence of two nearly same diseases/infections as a ‘compound disease’. This is different from the complex disease, which is formed by two dissimilar diseases. Here the effect and the cause of the disease is nearly the same, hence the diseases is ‘compounded’.

The aphorism here states that a stronger similar disease annihilates the weaker one, which is similar in phenomenon but differs in kind. But why does this happen? Why does the stronger similar disease annihilate the weaker? Hahnemann says that this happens due to the similarity in phenomenon. The stronger similar disease occupies the same seat as the weaker and the body now does not feel the weaker one, which thus ceases to exist. In the footnote he gives an example of a candle flame that becomes difficult to see in bright sunlight.

Just as I said in the lecture on aphorism 26, the explanation and the example of the candle given here are not perfect. The example of the candle is more of an analogy to understand the power of a stronger force, but it does not help us understand what happens in the body. The modus operandi of the natural cures given by Hahnemann is also debatable. We can explain it in terms of the Vital Force, as I did while talking about aphorism 17, but it is very difficult to explain Hahnemann’s explanation (that the VF cannot feel the weaker similar disease, hence it becomes extinguished) in biological terms. Hahnemann gave a possible mechanism, which was limited by the limitations of knowledge in his era. Instead of just dwelling on Hahnemann’s exact words here, let us try to explain Hahnemann’s observations in more scientific terms.

In the next aphorism, you will read an example of Measles curing Whooping Cough. How do we explain this biologically? Will the antibodies against measles have an effect on whooping cough? Highly unlikely! Then what would explain Hahnemann’s observation?

The answer to this probably lies in the different types of immunity that we have. The immune system protects organisms from infection with layered defenses of increasing specificity. In simple terms, physical barriers prevent pathogens such as bacteria and viruses from entering the organism. If a pathogen breaches these barriers, the innate immune system provides an immediate, but non-specific response. If pathogens successfully evade the innate response, vertebrates possess a second layer of protection, the adaptive immune system, which is activated by the innate response. Here, the immune system adapts its response during an infection to improve its recognition of the pathogen. This improved response is then retained after the pathogen has been eliminated, in the form of an immunological memory (antibodies), and allows the adaptive immune system to mount faster and stronger attacks each time this pathogen is encountered.

My hypothesis is that the reason for removal of a weaker but similar disease lies in our innate or non-specific immune response.

Microorganisms or toxins that successfully enter an organism encounter the cells and mechanisms of the innate immune system. The innate response is usually triggered when microbes are identified by pattern recognition receptors, which recognize components that are conserved among broad groups of microorganisms, or when damaged, injured or stressed cells send out alarm signals, many of which (but not all) are recognized by the same receptors as those that recognize pathogens. Innate immune defenses are non-specific, meaning these systems respond to pathogens in a generic way.

The major functions of the vertebrate innate immune system include:

  • Recruiting immune cells to sites of infection, through the production of chemical factors, including specialized chemical mediators, called cytokines.

  • Activation of the complement cascade to identify bacteria, activate cells and to promote clearance of dead cells or antibody complexes.

  • The identification and removal of foreign substances present in organs, tissues, the blood and lymph, by specialized white blood cells.

  • Activation of the adaptive immune system through a process known as antigen presentation.

  • Acting as a physical and chemical barrier to infectious agents.

It is now not difficult to see why a stronger similar disease might help eradicate a weaker one. The non-specific immunity is triggered by receptors, which are common to many pathogens. When two diseases have similar ‘phenomenon’, they are likely to elicit a similar non-specific immune response. A similar infection might trigger a stronger innate immune response, which is sufficient to get rid of the earlier infection. This now also resonates with our earlier explanation of vital force in cure. The examples of such diseases resulting in cure are difficult to find in modern literature, but we still have a plausible mechanism for Hahnemann’s observations. And the final proof lies in the facts that he derived from these observations – the need for similar medicines. And as homeopaths, we do know that his inferences have stood the test of time.

Before we move to the need for similar remedies, let us first study the examples that Hahnemann gave in support of his above statements. Aphorism 46 states:

§ 46

Many examples might be adduced of disease which, in the course of nature, have been homoeopathically cured by other diseases presenting similar symptoms, were it not necessary, as our object is to speak about something determinate and indubitable, to confine our attention solely to those (few) disease which are invariably the same, arise from a fixed miasm, and hence merit a distinct name.

Among these the smallpox, so dreaded on account of the great number of its serious symptoms, occupies a prominent position, and it has removed and cured a number of maladies with similar symptoms.

How frequently does smallpox produce violent ophthalmia, sometimes even causing blindness! And see! By its inoculation Dezoteux1 cured a chronic ophthalmia permanently, and Leroy2 another.

An amaurosis (vision loss) of two years’ duration, consequent on suppressed scald head, was perfectly cured by it, according to Klein.3

How often does smallpox cause deafness and dyspnoea! And both these chronic diseases it removed on reaching its acme, as J. Fr. Closs4 observed.

Swelling of the testicle, even of a very severe character, is a frequent symptom of small-pox, and on this account it was enabled, as Klein5 observed, to cure, by virtue of similarity, a large hard swelling of the left testicle, consequently on a bruise. And another observer6 saw a similar swelling of the testicle cured by it.

Among the troublesome symptoms of small-pox is a dysenteric state of the bowels; and it subdued, as Fr. Wendt7 observed, a case of dysentery, as a similar morbific agent.

Smallpox coming on after vaccination, as well on account of its greater strength as its great similarity, at once removes entirely the cow-pox homoeopathically, and does not permit it to come to maturity; but, on the other hand, the cow-pox when near maturity does, on account of its great similarity, homoeopathically diminish very much the supervening smallpox and make it much milder8, as Muhry9and many others testify.

The inoculated cow-pox, whose lymph, besides the protective matter, contains the contagion of a general cutaneous eruption of another nature, consisting of usually small, dry (rarely large, pustular) pimples, resting on a small red areola, frequently conjoined with round red cutaneous spots and often accompanied by the most violent itching, which rash appears in not a few children several days before, more frequently, however, after the red areola of the cow-pock, and goes off in a few days, leaving behind small, red, hard spots on the skin; – the inoculated cow-pox, I say, after it has taken, cures perfectly and permanently, in a homoeopathic manner, by the similarity of this accessory miasm, analogous cutaneous eruptions of children, often of very long standing and of a very troublesome character, as a number of observers assert.10

The cow-pox, a peculiar symptom of which is to cause tumefaction (swelling) of the arm11, cured, after it broke out, a swollen half-paralyzed arm.12

The fever accompanying cow-pox, which occurs at the time of the production of the red areola, cured homoeopathically intermittent fever in two individuals, as the younger Hardege13 reports, confirming what J. Hunter14 had already observed, that two fevers (similar diseases) cannot co-exist in the same body.

The measles bear a strong resemblance in the character of its fever and cough to the whooping-cough, and hence it was that Bosquillon15 noticed, in an epidemic where both these affections prevailed, that many children who then took measles remained free from whooping-cough during that epidemic. They would all have been protected from, and rendered incapable of being infected by, the whooping-cough in that and all subsequent epidemics, by the measles, if the whooping-cough were not a disease that has only a partial similarity to the measles, that is to say, if it had also a cutaneous eruption similar to what the latter possesses. As it is, however, the measles can but preserve a large number from whooping-cough homoeopathically, and that only in the epidemic prevailing at the time.

If, however, the measles come in with a disease resembling it in its chief symptom, the eruption, it can indisputably remove, and effect a homoeopathic cure of the latter. Thus a chronic herpetic eruption was entirely and permanently (homoeopathically) cured16 by the breaking out of the measles, as Kortum17 observed. An excessively burning miliary rash on the face, neck, and arms, that had lasted six years, and was aggravated by every change of weather, on the invasion of measles assumed the form of a swelling of the surface of the skin; after the measles had run its course the exanthema was cured, and returned no more.18

1Traite de l’inoculation, p.189.

2Heilkunde fur Mutter, p.384.

3Interpres clinicus, p.293.

4Neue Heilart der Kinderpocken. Ulm, 1769, p.68; and Specim., obs. No. 18.

5Opium cit.

6Nov. Actea Nat. cur., vol, I, obs. 22.

7Nachricht Von dem Krankeninstitut zu Erlangen, 1783.

8A new footnote is added here in the Sixth Edition, as follows:

This seems to be the reason for this beneficial remarkable fact, namely that since the general distribution of Jenner’s Cow-pox vaccination, human small-pox never again appeared as epidemically or virulently as 40-45 years before, when one city visited lost at least one-half and often three-quarters of its children by death of this miserable pestilence.

9Willian, Ueber die Kuhpockenimpfung, aus dem Engl., mit Zusatzen G.P. Muhry, Gottingen, 1808.

10Especially Clavier, Hurel and Desmormeaux, in the Bulletin des sciencs medicales, publie par les membres de l’ Eure, 1808, also in the Journal de medicine continue, vol. xv, p.206.

11Balhorn, in Hufeland’s Journal, 10, ii.

12Stevenson, in Duncan’s Annals of Medicine, lustr. 2, vol. I, pt. 2, No. 9.

13In Hufeland’s Journal, xxiii.

14On the Veneral Disease, p.4.

15Cullen’s Elements of Practical Medicine, pt. 2, I, 3, ch. vii.

16Or at least that symptom was removed.

17In Hufeland’s Journal, xx, 3, p.50.

18Rau, Ueber d. Werth des hom. Heidelb., 1824, p.85.

This aphorism is also filled with several gems, but they are not easy to see. The examples that Hahnemann gave in this aphorism are not his own direct observations. He has cited other authorities as a proof and validation of his own observations. Smallpox doesn’t occur anymore and most other examples are difficult to verify in modern times. While some observations might not have been accurate, we will have to trust Hahnemann and other observers for what they have remarked. I won’t dwell on each example here; instead I’ll show you the hidden gems in this aphorism.

In the beginning of this aphorism, Hahnemann states:

“…to confine our attention solely to those (few) diseases which are invariably the same, arise from a fixed miasm, and hence merit a distinct name…”

As I have said earlier, Hahnemann was well aware of infectious diseases and the principle of specific contagion causing specific disease. In modern terminology the ‘fixed miasm’ causing infectious diseases like Smallpox, Chickenpox, Measles etc, are nothing but bacteria and viruses. Ignoring this truth is like putting blinds on your eyes and denying the sun!

And he also says that such diseases merit a ‘distinct name’. Why would he suggest the use of distinct disease names if he had to ignore them altogether? This is not against the principle of individuality or totality of symptoms or vital force. While treating acutes, first find the remedies that match the presenting symptoms of the disease broadly, and then individualize to find the most suitable remedy amongst them. This holds true in most chronic cases too, but the variables there are much more and the treatment needs greater insight and patience.

An example of interest to me is:

“…the cow-pox when near maturity does, on account of its great similarity, homoeopathically diminish very much the supervening smallpox and make it much milder…”

What does this mean? It means that when two similar diseases, differing in kind, meet in our body, the stronger (smallpox) will remove the weaker (chickenpox) but the weaker also diminishes the effect of the stronger. This is also easy to explain. Due to the existing infection, the innate defense mechanism is already activated. When the stronger disease supervenes, the defense mechanism is able to deal with it more effectively, thus reducing its severity.

Another line that I would like to bring your attention to is:

“…The inoculated cow-pox, whose lymph, besides the protective matter, contains the contagion of a general cutaneous eruption of another nature…”

What can we learn from this sentence? Read carefully. Hahnemann is talking about the cowpox vaccination here. I have explained in an earlier lecture how the inoculation was done. What is significant here is the use of the word ‘besides’. Hahnemann is saying that the lymph that is used for cowpox inoculation has two distinct parts:

  1. the protective matter

  2. the contagion that results in eruptions

So he felt that what protects from future infections is distinct from the contagion. Technically this is right, as the antibodies that protect from the future infections are distinct from the contagion that contains the antigen. But Hahnemann was not aware of all this and if you look at the context in which he states this, his statement is wrong. Hahnemann’s observation shows the limitation of knowledge of his times (not his personal ignorance). Today we know that the protective effect results from the antibodies generated in response to the contagion and the inoculums does not have anything ‘protective’ besides the contagion.

And while we are discussing the effect of cowpox vaccination, let me point your attention towards the footnote number 8 to this aphorism.

This seems to be the reason for this beneficial remarkable fact namely that since the general distribution of Jenner’s Cow-pox vaccination, human small-pox never again appeared as epidemically or virulently as 40-45 years before when one city visited lost at least one-half and often three-quarters of its children by death of this miserable pestilence.”

Hahnemann is very categorically praising Jenner’s cowpox vaccination. He says that due to this vaccination, smallpox has significantly reduced in epidemy and virulence. This is not the only place where Hahnemann has praised Jenner’s work. You will find him mentioned in many places in Organon, Chronic Diseases and Lesser Writings of Hahnemann.

Today there is a very passionate debate about the usefulness and side effects of Vaccination. Today we are aware that vaccines have been a source of infection at times; their additives and preservatives can be harmful too. Many vaccines in the market are not effective and many are not needed. At the same time, the statistical data does show that vaccines can help in fighting epidemics and virulent diseases like Smallpox and Polio. The question is where does the balance lie? How much vaccination is right; at what age; in what diseases; in what form? It’s a much greater ethical debate and fresh research is needed to answer these questions.

Ponder over these thoughts and questions and in our next lecture, we will move ahead with Hahnemann and explore the need for similar medicines.

About the author

Dr. Manish Bhatia

Dr. Manish Bhatia

- BHMS, BCA, M.Sc Homeopathy (UK), CICH (Greece)
- Ass. Professor, Organon & Homeopathic Philosophy, SKH Medical College, Jaipur
- Founder Director of
- Editor, Homeopathy 4 Everyone
- Member, Advisory Board, Homeopathic Links
- Co-author - Homeopathy and Mental Health Care: Integrative Practice, Principles and Research
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- Awardee - Raja Pajwan Dev Award for Excellence in the Field of Medicine; APJ Abdul Kalam Award for Excellence in Homeopathy Education
- For consultation, seminars or clinical training, write to [email protected]


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