Classical Homoeopathic philosophy revolves around the following principles:
1) The Law of Similars:
"Any substance which can produce a totality of symptoms in a healthy human being, can cure that totality of symptoms in a sick human being".
The knowledge of which remedy to prescribe for a patient comes from an understanding of what are called "provings".
Provings occur when groups of healthy people, under double-blind conditions, take remedies and keep meticulous diaries over following days, weeks and months, noting down accurately all the resulting symptoms. These can be physical or mental/emotional.
All these symptoms (both objective and subjective) are collated and written up in a book called aMateria Medica. Homoeopaths, through many years' extensive study, have a good working knowledge of what is contained in a Materia Medica. Therefore, when sick people present at the Clinic and their signs and symptoms are taken down, the "Simillimum" or similar remedy which closely matches the current symptom picture is selected.