(Plato: the myth of the cave) (from "The Republic" by Plato, book VII, 514 a)
Translation:
Think of men in an underground cave, equipped with an opening towards the light that occupy the entire long wall. They have been closed there since childhood, burdened with chains around their necks and legs that force them to remain there. and to look only forward, since? the chain around their neck prevents them from turning their heads around. High above them, a distant flame shines