It's a puzzle — the deepest puzzle I know. The question is: What are we?
One answer, from physicist-novelist Alan Lightman, is we are stuff. Just stuff.
"Let me explain. A highly unpleasant idea, but one that has been accepted by scientists over the last couple of centuries, is that we human beings, and all living beings, are completely material. That is, we are made of material atoms, and only material atoms.
