Homeopathy : Homeopathy is a system of alternative medicine created in 1796 by Samuel Hahnemann, based on his doctrine of like cures like (similia similibus curentur), a claim that a substance that causes the symptoms of a disease in healthy people would cure similar symptoms in sick people.
Hahnemann's concept : The term "homeopathy" was coined by Hahnemann and first appeared in print in 1807. Hahnemann conceived of homeopathy while translating a medical treatise by the Scottish physician and chemist William Cullen into German. Being sceptical of Cullen's theory concerning cinchona's use for curing malaria, Hahnemann ingested some bark specifically to investigate what would happen. He experienced fever, shivering and joint pain: symptoms similar to those of malaria itself. From this, Hahnemann came to believe that all effective drugs produce symptoms in healthy individuals similar to those of the diseases that they treat, in accord with the "law of similars" that had been proposed by ancient physicians.
Provings : Hahnemann began to test what effects substances produced in humans, a procedure that would later become known as "homeopathic proving". These tests required subjects to test the effects of ingesting substances by clearly recording all of their symptoms as well as the ancillary conditions under which they appeared. He published a collection of provings in 1805, and a second collection of 65 preparations appeared in his book, Materia Medica Pura, in 1810.
Miasms and disease : In the Organon, Hahnemann introduced the concept of "miasms" as "infectious principles" underlying chronic disease. Hahnemann associated each miasm with specific diseases, and thought that initial exposure to miasms causes local symptoms, such as skin or venereal diseases. If, however, these symptoms were suppressed by medication, the cause went deeper and began to manifest itself as diseases of the internal organs. Homeopathy maintains that treating diseases by directly alleviating 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 be corrected only by removing the deeper disturbance of the vital force. Hahnemann's hypotheses for the direct or remote cause of all chronic diseases (miasms) originally presented only three, psora (the itch), syphilis (venereal disease) or sycosis (fig-wart disease). Of these three 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 tuberculosis and cancer miasms. The law of susceptibility implies that a negative state of mind can attract hypothetical disease entities called "miasms" to invade the body and produce symptoms of diseases.Hahnemann rejected the notion of a disease as a separate thing or invading entity, and insisted it was always part of the "living whole". Hahnemann coined the expression "allopathic medicine", which was used to pejoratively refer to traditional Western medicine. Hahnemann's miasm theory remains disputed and controversial within homeopathy even in modern times. The theory of miasms has been criticized as an explanation developed by Hahnemann to preserve the system of homeopathy in the face of treatment failures, and for being inadequate to cover the many hundreds of sorts of diseases, as well as for failing to explain disease predispositions, as well as genetics, environmental factors, and the unique disease history of each patient.