Petra Weiermayer et al.

According to the simile principle (Similia similibus curentur, or ‘Let like be cured by like’), classical (=individualized) homeopathic therapy is based on the individual and not on the indication. Based on the following three facts, the discussion of the evidence in human and veterinary homeopathy lays the foundations for a comprehensive presentation of the evidence on homeopathy: (a) homeopathic medicinal products without indication are 100% identical with regard to production, quality, safety, and principles of application, regardless of whether they are used in animals or humans; (b) if the simile principle is adhered to that classical (=individualized) homeopathic therapy is based on the individual and not on the indication; and (c) if the proof of effectiveness of individualized homeopathy in one or more indications is available, the logical consequence seems to be that it can be concluded that it is effective in other indications.