All the life upon the globe, including man with all his marvelous powers, surely originated upon the globe, surely arose out of the non-living and the non-thinking, not by the fiat of some power external to nature, but through the creative energy inherent in nature and ever active there.  The great physical instrumentality was heat—­without heat the reaction called life could never have taken place.  This fact has led a French biologist to say that life is only a surface accident in the history of the thermic evolution of the globe.  Without the disintegration of the rocks and the formation of the soil and the precipitation of watery vapor, which was indirectly the work of heat, the vegetable and the animal could not have developed.  If we succeed in proving that all these things are of chemico-mechanical origin, we still want to know who or what instituted these chemical and mechanical powers and the laws that govern them.  Creation by chemistry and mechanics is as mysterious as creation by miracle.  We must still have a creator, while we can do nothing with him nor find any place for him in an endless, beginningless, infinite series of events.  So there we are.  We go out of the same door by which we came in.

When all life vanishes from the earth, as it will when the condition of heat and moisture has radically changed, and eternal refrigeration sets in—­what then?  The potencies of matter will not have changed and life will reappear and go through its cycle again on some other sphere.

Life began upon this earth not by miracle in the old sense, but by miracle in the new scientific sense—­by the immanence and ceaseless activity of the creative energy in the physical world about us—­in the sunbeam, in the rains, in the snows, in the air currents, and in the soil underfoot; in oxygen, hydrogen, carbon, nitrogen, in lime, iron, silex, phosphorus, and in all the rest of them.  Each has its laws, its ways, its fixed mode of procedure, its affinities, its likes and dislikes, and life is bound up with all of them.  If we hypothesize the ether to explain certain phenomena, why should we not hypothesize a vital force to account for other mysteries?

The inorganic passes into the organic as night passes into day.  Where does one end and the other begin?  No man can tell.  There is no beginning and no ending of either, and yet night comes and goes and day comes and goes—­a constant becoming and a constant ending.  We are probably in the midday of the life of the globe—­life huge and rank and riotous—­the youth of life has passed, life more sedate and aspiring and spiritual has come.  The gigantic has gone or is going, the huge monsters of the sea and of the land have had their day, man appears at the end of the series of lesser but more complete forms.