The fundamental idea of homeopathy is the Similarity (or Similia) Principle: ‘Similia similibus curentur’ (‘Let like be cured by like’), stated by the German physician Samuel Hahnemann (1755–1843) in 1796. This implies that substances capable of causing disorder in healthy subjects are used as medicines to treat similar patterns of disorder experienced by ill people. Hippocrates wrote of curing ‘like with like’ more than 2,000 years ago but it was formally systematized by Hahnemann. He viewed health as a dynamic process tending to maintain a state of optimum equilibrium. Homeopathic medicines are aimed to direct and stimulate the body’s self-regulatory mechanisms.
A second principle in homeopathy is individualization of treatment for the patient. The characteristics of the chosen medicine should be as similar as possible to the characteristics of the illness in the patient. This closest match is called the ‘simillimum’. Similarity may be at the ‘whole person’ level, taking into account the symptoms and signs of the disease, the patient’s physical build, personality, temperament and genetic predispositions. This high level of individualization is not always required: ‘similarity’ may be at a more specific, local level, especially in the treatment of acute conditions.
A third principle is the use of the minimum dose. The doses used in homeopathy range from those that are similar in concentration to some conventional medicines to very high dilutions containing no material trace of the starting substance – the latter are referred to as ‘ultra-molecular’ dilutions. Vigorous shaking of the solution together with impact or ‘elastic collision’ (known as succussion) during the manufacturing process is a key element in the production of homeopathic medicines.