This refilling of the Mediterranean, which by the rough chronology we are employing in this book may have happened somewhen between 30,000 and 10,000 B.C., must have been one of the greatest single events in the pre-history of our race. If the later date is the truer, then, as the reader will see plainly enough after reading the next two chapters, the crude beginnings of civilization, the first lake dwellings and the first cultivation, were probably round that eastern Levantine Lake into which there flowed not only the Nile, but the two great rivers that are now the Adriatic and the Red Sea. Suddenly the ocean waters began to break through over the westward hills and to pour in upon these primitive peoples--the lake that had been their home and friend became their enemy; its waters rose and never abated; their settlements were submerged; the waters pursued them in their flight. Day by day and year by year the waters spread up the valleys and drove mankind before them. Many must have been surrounded and caught by the continually rising salt flood. It knew no check; it came faster and faster; it rose over the treetops, over the hills, until it had filled the whole basin of the present Mediterranean and until it lapped the mountain cliffs of Arabia and Africa. Far away, long before the dawn of history, this catastrophe occurred. XII EARLY THOUGHT[62] § 1. _Primitive Philosophy._ § 2. _The Old Man in Religion._ § 3. _Fear and Hope in Religion._ § 4. _Stars and Seasons._ § 5. _Story-telling and Myth-making._ § 6. _Complex Origins of Religion._ § 1 Before we go on to tell how 6000 or 7000 years ago men began to gather into the first towns and to develop something more than the loose-knit tribes that had hitherto been their highest political association, something must be said about the things that were going on inside these brains of which we have traced the growth and development through a period of 500,000 years from the Pithecanthropus stage. What was man thinking about himself and about the world in those remote days?