Homeopathic Medicine is a medical experimental and clinical method founded on the law of similars :
 
“similia similibus curentur”.
 
All the substances able to alter the health state of a healthy person producing an ensemble of symptoms “a pathogenesis”, when administered to a ill person which shows symptoms similar to those revealed on the healthy persons which experimented the substance, act in a homeopathic fashion.
 
The law of similars shows the correlation between the power of a substance to alter the health state and its therapeutic action; in fact every substance biologically activated by the experimentation on the healthy produces symptoms typical and characteristic.
 
"To treat a patient following the law of similars” means therefore to use for the cure only those substances that have revealed, in healthy persons under experimentation, temporary symptoms similars to those shown by a ill person.