I've always felt that death is the greatest invention of life. I'm sure that life evolved without death at first and found that without death, life didn't work very well because it didn't make room for the young. It didn't know how the world was fifty years ago. It didn't know how the world was twenty years ago. It saw it as it is today, without any preconceptions, and dreamed how it could be based on that. We're not satisfied based on the accomplishment of the last thirty years. We're dissatisfied because the current state didn't live up to their ideals. Without death there would be very little progress.