I learnt it (the charm) on a campaign over there, from one of the Thracian physicians of Zalmoxis who are said to make one immortal. This Thracian said that the Greeks were right in advising as I told you just now: “but Zalmoxis,” he said, “our king, who is a god, says that as you ought not to attempt to cure eyes without head, or head without body, so you should not treat a body without soul… And the treatment of the soul, so he said… is by means of certain charms, and these charms are words of the right sort…”

Plato, Charmides