Once upon a time, long ago, an older man, a youth, and a young lady made history. Their time is far enough behind us so that we can reflect upon their significance. A hundred years ago we might have thought that the late Stone Age, known as the Neolithic Era, was a threshold, over which we stepped, to become modern man. Nowadays, in the best new light shed on the expanding boundaries of anthropology, and on the physics of time, we are not sure when modern man began, if it matters. The history of the trio in this narrative is not from the very distant past, before our use of language, or...