"We are too feeble and sluggish to make our way out to the upper limit of the air. If someone could reach the summit, or put on wings and fly aloft, when he put up his head he would see the world above, just as fishes see our world when they put up their heads out of the sea; and if his nature were able to bear the sight, he would recognize that that is the true heaven."

Source: Plato, Julius A. Sigler (1997). “Education: Ends and Means”, p.21, University Press of America