What an astonishing revelation, for instance, that the soil was born of the rocks, and is still born of the rocks; that every particle of it was once locked up in the primitive granite and was unlocked by the slow action of the rain and the dews and the snows; that the rocky ribs of the earth were clothed with this fertile soil out of which we came and to which we return by their own decay; that the pulling-down of the inorganic meant the building-up of the organic; that the death of the crystal meant the birth of the cell, and indirectly of you and me and of all that lives upon the earth.

Had there been no soil, had the rocks not decayed, there had been no you and me.  Such considerations have long made me feel a keen interest in geology, and especially of late years have stimulated my desire to try to see the earth as the geologist sees it.  I have always had a good opinion of the ground underfoot, out of which we all come, and to which we all return; and the story the geologists tell us about it is calculated to enhance greatly that good opinion.

I think that if I could be persuaded, as my fathers were, that the world was made in six days, by the fiat of a supernatural power, I should soon lose my interest in it.  Such an account of it takes it out of the realm of human interest, because it takes it out of the realm of natural causation, and places it in the realm of the arbitrary, and non-natural.  But to know that it was not made at all, in the mechanical sense, but that it grew—­that it is an evolution as much as the life upon the surface, that it has an almost infinite past, that it has been developing and ripening for millions upon millions of years, a veritable apple upon the great sidereal tree, ameliorating from cycle to cycle, mellowing, coloring, sweetening—­why, such a revelation adds immensely to our interest in it.

As with nearly everything else, the wonder of the world grows the more we grasp its history.  The wonder of life grows the more we consider the chaos of fire and death out of which it came; the wonder of man grows the more we peer into the abyss of geologic time and of low bestial life out of which he came.

Not a tree, not a shrub, not a flower, not a green thing growing, not an insect of an hour, but has a background of a vast aeon of geologic and astronomic time, out of which the forces that shaped it have emerged, and over which the powers of chaos and darkness have failed to prevail.

The modern geologist affords us one of the best illustrations of the uses of the scientific imagination that we can turn to.  The scientific imagination seems to be about the latest phase of the evolution of the human mind.  This power of interpretation of concrete facts, this Miltonic flight into time and space, into the heavens above, and into the bowels of the earth beneath, and bodying forth a veritable history, a warring of the powers of light and darkness, with the triumph of the angels of light and life, makes