Homeopathy is a vitalist philosophy in that it interprets diseases and sickness as caused by disturbances in a hypothetical vital force or life force and sees these disturbances as manifesting themselves in unique symptoms. Homeopathy maintains that the vital force has the ability to react and adapt to internal and external causes, which homeopaths refer to as the "law of susceptibility". The law of susceptibility states that a negative state of mind can attract hypothetical disease entities called "miasms" to invade the body and produce symptoms of diseases. However, Hahnemann rejected the notion of a disease as a separate thing or invading entity and insisted that it was always part of the "living whole"

Law of similars

Hahnemann observed from his experiments with cinchona bark, used as a treatment for malaria, that the effects he experienced from ingesting the bark were similar to the symptoms of malaria. He therefore reasoned that cure proceeds through similarity, and that treatments must be able to produce symptoms in healthy individuals similar to those of the disease being treated. Through further experiments with other substances, Hahnemann conceived of the "law of similars", otherwise known as "like cures like" (Latin: similia similibus curentur) as a fundamental healing principle. He believed that by inducing a disease through use of drugs, the artificial symptoms empowered the vital force to neutralise and expel the original disease and that this artificial disturbance would naturally subside when the dosing ceased.

Miasms and disease

Hahnemann found as early as 1816 that the patients he treated through homeopathy still suffered from chronic diseases that he was unable to cure.[26] In 1828, he introduced the concept of miasms, which he regarded as underlying causes for many known diseases. A miasm is often defined by homeopaths as an imputed "peculiar morbid derangement of [the] vital force". Hahnemann associated each miasm with specific diseases, with each miasm seen as the root cause of several diseases. According to Hahnemann, initial exposure to miasms causes local symptoms, such as skin or venereal diseases, but if these symptoms are suppressed by medication, the cause goes deeper and begins to manifest itself as diseases of the internal organs. Homeopathy maintains that treating diseases by directly opposing their symptoms, as is sometimes done in conventional medicine, is ineffective because all "disease can generally be traced to some latent, deep-seated, underlying chronic, or inherited tendency". The underlying imputed miasm still remains, and deep-seated ailments can only be corrected by removing the deeper disturbance of the vital force.

Hahnemann's miasm theory remains disputed and controversial within homeopathy even in modern times. In 1978, Anthony Campbell, then a consultant physician at The Royal London Homeopathic Hospital, criticised statements by George Vithoulkas claiming that syphilis, when treated with antibiotics, would develop into secondary and tertiary syphilis with involvement of the central nervous system. This conflicts with scientific studies, which indicate that penicillin treatment produces a complete cure of syphilis in more than 90% of cases. Campbell described this as "a thoroughly irresponsible statement which could mislead an unfortunate layman into refusing orthodox treatment".

Originally Hahnemann presented only three miasms, of which the most important was "psora" (Greek for itch), described as being related to any itching diseases of the skin, supposed to be derived from suppressed scabies, and claimed to be the foundation of many further disease conditions. Hahnemann believed psora to be the cause of such diseases as epilepsy, cancer, jaundice, deafness, and cataracts. Since Hahnemann's time, other miasms have been proposed, some replacing one or more of psora's proposed functions, including tubercular miasms and cancer miasms.