After watching "Why We Fight"

"'When you were last here,' said Aslan, 'that hollow was a pool, and when you jumped into it you came to the world where a dying sun shone over the ruins of Charn. There is no pool now. That world is ended, as if it had never been. Let the race of Adam and Eve take warning.'

'Yes, Aslan,' said both the children. But Polly added, "But we're not quite as bad as that world, are we, Aslan?'

'Not yet, Daughter of Eve,' he said. 'Not yet. But you are growing more like it. It is not certain that some wicked one of your race will not find out a secret as evil as the Deplorable Word and use it to destroy all living things. And soon, very soon, before you are an old man and an old woman, great nations in your world will be ruled by tyrants who care no more for joy and justice and mercy than the Empress Jadis. Let your world beware. That is the warning.'"

- C.S. Lewis, The Magician's Nephew