There is the fable of Orpheus and Eurydice. Eurydice had been captured and taken to the infernal regions, and Orpheus went after her, taking with him his harp and playing as he went. When he came to Pluto's realm he began to play, and Sysiphus, charmed by the music, sat down upon the stone that he had been heaving up the mountain's side for so many years, and which continually rolled back upon him; Ixion paused upon his wheel of fire; Tantalus ceased his vain efforts for water; the daughters of the Danaides left off trying to fill their sieves with water; Pluto smiled, and for the first time in the history of hell the cheeks of the Furies were wet with tears. The god relented, and said, "Eurydice may go with you, but you must not look back." So Orpheus again threaded the caverns, playing as he went, and as he reached the light he failed to hear the footsteps of Eurydice. He looked back, and in a moment she was gone. Again and again Orpheus sought his love. Again and again looked back.
This fable gives the idea of the perpetual effort made by the human mind to rescue truth from the clutch of error.
Some time Orpheus will not look back. Some day Eurydice will reach the blessed light, and at last there will fade from the memory of men the monsters of superstition.