pre history

The Hunter gatherers thought that evil spirits caused disease. 

To cure disease they wore amulets to keep away spirits.

They also put a hole in the patient's head to release evil spirits from the body ( trephanning ).

The farmers thought that natural things caused disease.

If you had a sore throat, one of the female farmers would mix honey and herbs for you to drink. 

They focused on natural cures.

The hunters travelled a lot, so they were never in risk of being infected by polluted water etc.

The farmers settled into areas and were therefore reluctant to catching a disease.