Various ancient civilizations, from the Egyptians to the Chinese, developed their own unique systems for practicing medicine in the fields of herbalism, anatomy, public health, and clinical diagnostics1. Medicine was not practiced by physicians, but rather by the common people through observation and empiricism. The great Greek poet Homer described Egypt as a land where “the earth, the giver of grain, bears the greatest store of drugs” and where “every man is a physician”. Homer’s mythology does have some truth to it. In the famous Ebers papyrus, dating back to 1550 B.C., the ancient Egyptians describe more than 700 medicinal formulas; some were incantations and placebos that delivered their therapeutic effects through spiritual healing.