Amid thousands of symptoms, which ones are most valuable in choosing a medicine?
According to §7, the basis of medicine selection is the totality of symptoms — the complete picture formed by all the patient's physical and mental symptoms together is matched against the medicine's proving picture.
But not all symptoms carry equal weight. The teaching of §153: the unusual, rare and peculiar (strange, rare, peculiar) symptoms are the most valuable. For example — complete absence of thirst in fever, pain relieved by heat, a sore throat moving from left to right — symptoms of this kind single out a medicine.
On the other hand, symptoms that are common to almost all patients (such as feeling weak when there is fever) help comparatively less in choosing a medicine. An experienced doctor therefore identifies the characteristic symptoms first when hearing a case.