But if you write a version of Ragnarok in the twenty-first century, it is haunted by the imagining of a different end of things. We are a species of animal which is bringing about the end of the world we were born into. Not out of evil or malice, or not mainly, but because of a lopsided mixture of extraordinary cleverness, extraordinary greed, extraordinary proliferation of our own kind, and a biologically built-in short-sightedness.