The conception of evolution in its turn now demands a definite description.  How are we to regard the material things of the earth?  Are they permanent and unchanged since the beginning of time, unchanging and unchangeable at the present?  We do not need Herbert Spencer’s elaborate demonstration that this is unthinkable, for we all know from daily experience that things do change and that nothing is immutable.  Did things have a finite beginning, and have they been “made” by some supernatural force or forces, personified or impersonal, different from those agencies which we may see in operation at the present time?  So says the doctrine of special creation.  Finally, we may ask if things have changed as they now change under the influence of what we call the natural laws of the present, and which if they operated in the past would bring the world and all that is therein to be just what we find now.  This is the teaching of the doctrine of evolution.  It is a simple brief statement of natural order.  And because it has followed the method of common sense, science asserts that changes have taken place, that they are now taking place, and furthermore that it is unnecessary to appeal to other than everyday processes for an explanation of the present order of things.

Wherever we look we see evidence of nature’s change; every rain that falls washes the earth from the hills and mountains into the valleys and into the streams to be transported somewhere else; every wind that blows produces its small or greater effect upon the face of the earth; the beating of the ocean’s waves upon the shore, the sweep of the great tides,—­these, too, have their transforming power.  The geologists tell us that such natural forces have remodeled and recast the various areas of the earth and that they account for the present structure of its surface.  These men of science and the astronomers and the physicists tell us that in some early age the world was not a solid globe, with continents and oceans on its surface, as now; that it was so very hot as to be semi-fluid or semi-solid in consistency.  They tell us that before this time it was still more fluid, and even a mass of fiery vapors.  The earth’s molten bulk was part of a mass which was still more vast, and which included portions which have since condensed to form the other bodies of the solar system,—­Mars and Jupiter and Venus and the rest,—­while the sun remains as the still fiery central core of the former nebulous materials, which have undergone a natural history of change to become the solar system.  The whole sweep of events included in this long history is called cosmic evolution; it is the greater and more inclusive process comprising all the transformations which can be observed now and which have occurred in the past.