Will human nature itself change? Will we soon pass some point where we are so altered by our imaginations and inventions as to be unrecognizable to Shakespeare or the writers of the ancient Greek plays?

No one knows, but many are trying to imagine such a world. They describe our children and grandchildren as no longer really being like us. They call them trans-human, or post-human. They see our lives changing more dramatically in the next few decades than in most of recorded history. And who knows? Perhaps they are right.