I will take one example to serve for an introduction to the story of man. It illustrates what I mean by saying that a certain childish directness is needed to see the truth about the childhood of the world. It illustrates what I mean by saying that a mixture of popular science and journalistic jargon have confused the facts about the first things, so that we cannot see which of them really comes first. It illustrates, though only in one convenient illustration, all that I mean by the necessity of seeing the sharp differences that give its shape to history, instead of being submerged in all these generalisations about slowness and sameness.