Similia similibus curentur is Latin for “let likes be cured by likes”. It is the founding maxim of homeopathy and the formal statement of the law of similars: the idea that a substance able to produce a particular set of symptoms in a healthy person can be used, in a potentised form, to treat a patient whose illness shows a matching symptom picture. In practice the word “like” is doing a lot of work — the match is between patterns of symptoms, not between a drug and a disease name.
This guide takes the phrase apart word by word, explains how the principle is actually applied in a consultation, and separates it from the older medical principle it was written to oppose.
What the Latin Actually Says
The phrase is short, and each word carries weight:
- Similia — “like things”, plural. Similar things, not identical ones.
- Similibus — “by like things”, again plural: the similar is treated by the similar.
- Curentur — a subjunctive passive verb form meaning “let them be cured” or “may they be cured”.
So the sentence is not a description of a mechanism and not a diagnosis; it is an instruction about method — a rule of prescribing. Homeopaths read it as: match the remedy to the patient’s symptom picture, not to the name of the disease.
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To understand the law of similars, it helps to see what it replaced. Long before Hahnemann, conventional therapeutics worked largely by the principle contraria contrariis curentur — “opposites are cured by opposites”. A fever was cooled, a constipation purged, an excess of one humour balanced with its contrary.
Hahnemann deliberately inverted this:
- Contraria contrariis (opposites): suppress or reverse the symptom. Antipyretic for fever, laxative for constipation. The symptom is the problem to be removed.
- Similia similibus (similars): match the symptom picture. The symptom is read as a signal of the patient’s disturbed state, and the remedy is chosen because it can reproduce that same pattern.
Modern conventional medicine does not work solely by “opposites” — vaccines, immunotherapy and allergen desensitisation are recognisably “like” principles in their own right. The distinction homeopaths draw is not “opposite versus similar” as a law of nature, but “disease-level versus person-level matching”.
Where the “Like” Comes From: Provings
The rule is only usable if you know what each substance can produce. That knowledge comes from provings — systematic experiments in which healthy volunteers take a substance and record every symptom that appears. The resulting symptom records are collected into the materia medica and indexed by symptom in the repertory.
This is why the law of similars and the proving method are inseparable. Without provings, “like” would be guesswork; with them, it becomes an indexed comparison between a substance’s symptom profile and the patient’s case.
How the Principle Is Applied in a Consultation
Applying the law of similars is a process of narrowing, not a single flash of insight. In outline:
- Take the case. The homeopath records the complaint in detail — location, sensation, timing, what makes it better or worse — plus general characteristics such as thermal preference, thirst, sleep, digestion and mood.
- Repertorise. These characteristic symptoms are looked up in the repertory to see which remedies appear across the largest number of the patient’s most unusual or striking symptoms.
- Compare materia medica. The shortlisted remedies are read in full to see which one matches the whole picture, not just one line.
- Choose potency and repetition. The remedy is then given in a potency and frequency considered appropriate to whether the situation is acute or long-standing.
Note the emphasis: the search is for the patient’s most characteristic symptoms, not their most common ones. A headache that everyone gets is less useful for matching than a headache that is always better for cold applications and always comes with irritability about being interrupted.
Similar, Not Identical
A frequent misunderstanding is that homeopathy treats “like with like” in the sense of giving a diluted version of the same thing — the way an allergy shot contains traces of the allergen. That is a different idea.
In homeopathy the substance is usually unrelated to the disease. The match is between the symptom profile the substance produced in provings and the symptom profile the patient is expressing. The substance need not be the causative agent, and usually is not.
Common Misreadings of the Phrase
- “It means treat poison with poison.” No. The remedy is not given at toxic strength; potentisation removes measurable quantity of the original substance.
- “It means one remedy per disease.” No, and this is the point of individualisation: two people with the same diagnosis may need different remedies.
- “It is the same as vaccination.” Not the same. Vaccination uses an identifiable immunological agent to generate specific immunity; the law of similars is a prescribing rule based on symptom matching.
- “It is a proven law of nature.” It is a foundational principle within homeopathy. Whether remedies produce effects beyond placebo is contested in the wider scientific literature, and honest practitioners say so.
Why the Maxim Still Matters
The phrase is not decorative. It is the reason homeopathic consultations are long, why case-taking is exhaustive, why the repertory exists, and why remedies are matched to the individual rather than to a diagnosis. If you remove similia similibus curentur, you do not get a simplified homeopathy — you get a different therapy altogether.
Frequently Asked Questions
What does similia similibus curentur mean in English?
“Let likes be cured by likes.” It is the Latin expression of the law of similars, the principle that a substance producing a set of symptoms in a healthy person is used to treat a similar symptom picture in a patient.
Who first used the phrase?
It is the maxim associated with Samuel Hahnemann, who articulated the law of similars in the 1790s and built homeopathy around it. The underlying observation that “like treats like” appears in much older medical writing.
Is the law of similars the same as the law of opposites?
No, they describe opposite strategies. Conventional drug therapy traditionally works by opposing the symptom; homeopathy matches it. Some modern therapies, such as desensitisation, use like-principles in a different framework.
Does the remedy have to be the substance that caused the illness?
No. The match is between the remedy’s proving symptoms and the patient’s symptoms — not between the remedy and the original cause of the complaint.
Can I apply the law of similars by myself?
You can learn the method for simple, self-limiting complaints, but chronic, recurring or serious conditions need proper case-taking. Self-prescribing on partial information is a common reason remedies appear not to work.
General educational content; not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified clinician for serious or worsening symptoms.
