So the Ice Ages and their glaciers and the Romans and their Cæsars melted away. We know them only by the marks they left on the walls of time. But why this constant doing and undoing of things? We have seen it going on from the very beginning; rock crumbling to dust, dust changing back to rock; rocks raised up into mountains, mountains worn down to plains; then more mountains, and on through the same cycle of endless change; as if always starting the whole thing over again.
What is it all about? Are we getting anywhere? If so, where?
Ever since men looked out upon the world around them and began to think, they have puzzled not only about the causes but the purpose of this endless drama of creation and decay. Some said one thing; some said another. The Persian poet who wrote those fine lines about the lion and the lizard in the ruins of the palaces meant to say that's all that everything comes to; all things, men included, return to the elements of which they were made and that's the end of them. So, said he, what's the use of bothering one's head about it? There's nothing to be learned. One verse of his famous song reads like this:
"Myself when young did eagerly frequent
Doctor and saint, and heard great argument
About it and about; but evermore
Came out by the same door wherein I went."
But Science, as we shall now see, has a better answer.
I. Nothing Happens
In the first place you must have noticed as we came along through this little book that nothing happens in this world of ours; everything is under a government of laws. Not only did it turn out that there was method in the apparent madness of the sea but we found method everywhere. It was not chance that made our worlds, whether they were born full-grown or grew up piece by piece. And we see the same forces at work in small things as in the great. The force that keeps the earth in its orbit is just as careful to catch and plant the tiny seeds of the grasses and the pine-trees drifting forward in the wind, so keeping the world clothed with life and verdure.