Among the traditions of the Greeks was one of an ancient hero whose name, Prometheus, signified “forethought,” and his brother Epimetheus, whose name meant “afterthought.”
It was Prometheus who stole fire from Zeus and brought it to mortals, and who taught them in all the useful arts and sciences.
It was Epimetheus who, against the advice of his wiser brother, became flattered by the charms of Pandora and prevailed upon her to open the box from which then escaped all the evils that have since plagued mankind. But the tradition chiefly relates the punishment inflicted by Zeus upon Prometheus for stealing the divine fire.
He was caused to be chained to a rock upon the side of a mountain, and there, defenseless, he was attacked every day by a huge bird, an eagle or a vulture, which feasted upon his liver. Each night his wounds were healed, only to be subjected to the attack of the evil bird the following day.
This continued until after eons of torture, Zeus relented and permitted Heracles to kill the bird and break the chains of Prometheus.
Our adjective Promethean may thus be connected with recurring ills, reminiscent of the punishment of this mythical hero, or with any of the many skills and arts credited to his beneficence.