Organon §135

To fully prove a substance multiple tests, with provers of both genders and various constitutions, are needed.

The complex of all disease elements which a medicine is capable of engendering is only brought near to completeness by means of multiple observations employed upon many differing qualified persons, both male and female. One can only be assured of having thoroughly proven a medicine for the disease states which it can arouse (i.e. , for its pure powers in altering the human condition) when subsequent provers can notice little about the medicine that is new and they almost always perceive in themselves the same symptoms that have already been observed by others.