How long I am to exist is not mine to decide, but how long I shall go on existing in my present way is in my own control. And what, you ask, is the fullest span of life? It is living until you possess wisdom. Such a one may indeed exult boldly and give thanks to the gods. Indeed, he may count himself nature's creditor for having lived. He will indeed have the right to do so, for he has paid her back a better life than he has received. Had another year been added, it would merely have been like the past. We have had the joy of learning the truth about the universe. By what successive changes she summons back the