Watchfulness, Overcome
Even many eyes cannot watch if the watcher falls asleep, illustrating the need for vigilance.
Argus is fabled to have had a hundred eyes in his head, only two of which ever slept at once. Jupiter sent Mercury to slay him. Mercury put on his winged slippers, took his sleep-producing wand, and hastened to the side of Argus. He presented himself in the guise of a shepherd with his flock. Mercury began to play upon the Pandean pipes. Argus listened, delighted with the new kind of music, and invited the young shepherd to sit beside him. Mercury sat down, told stories, and played the most soothing strains upon his pipes, till it grew late, hoping to lock in sleep the watchful eyes of Argus. At length, as Mercury played, and told a long story of the discovery of his wonderful instrument, he saw the hundred eyes all closed. The head of Argus leaned upon his breast, when Mercury cut it off with a stroke, and tumbled it down the rocks. The hundred eyes availed not while the watcher slept. Juno took them, and set them in the feathers of the tail of her peacock, where they remain to this day.