The Breath of Life

by John Burroughs

IX

The evolution of life is, of course, bound up with the evolution of the world. As the globe has ripened and matured, life has matured; higher and higher forms—forms with larger and larger brains and more and more complex nerve mechanisms—have appeared.

Physicists teach us that the evolution of the primary elements—hydrogen, oxygen, nitrogen, carbon, calcium, and the like—takes place in a solar body as the body cools. As temperature decreases, one after another of the chemical elements makes its appearance, the simpler elements appearing first, and the more complex compounds appearing last, all apparently having their origin in some simple parent element. It appears as if the evolution of life upon the globe had followed the same law and had waited upon the secular cooling of the earth.

Does not a man imply a cooler planet and a greater depth and refinement of soil than a dinosaur? Only after a certain housecleaning and purification of the elements do higher forms appear; the vast accumulation of Silurian limestone must have hastened the age of fishes. The age of reptiles waited for the clearing of the air of the burden of carbon dioxide. The age of mammals awaited the deepening and the enrichment of the soil and the stability of the earth's crust. Who knows upon what physical conditions of the earth's elements the brain of man was dependent? Its highest development has certainly taken place in a temperate climate. There can be little doubt that beyond a certain point the running-down of the earth-temperature will result in a running-down of life till it finally goes out. Life is confined to a very narrow range of temperature. If we were to translate degrees into miles and represent the temperature of the hottest stars, which is put at 30,000 degrees, by a line 30,000 miles long, then the part of the line marking the limits of life would be approximately three hundred miles.

Life does not appear in a hard, immobile, utterly inert world, but in a world thrilling with energy and activity, a world of ceaseless transformations of energy, of radio-activity, of electro-magnetic currents, of perpetual motion in its ultimate particles, a world whose heavens are at times hung with rainbows, curtained with tremulous shifting auroras, and veined and illumined with forked lightnings, a world of rolling rivers and heaving seas, activity, physical and chemical, everywhere. On such a world life appeared, bringing no new element or force, but setting up a new activity in matter, an activity that tends to check and control the natural tendency to the dissipation and degradation of energy. The question is, Did it arise through some transformation of the existing energy, or out of the preëxisting conditions, or was it supplementary to them, an addition from some unknown source? Was it a miraculous or a natural event? We shall answer according to our temperaments.

One sees with his mind's eye this stream of energy, which we name the material universe, flowing down the endless cycles of time; at a certain point in its course, a change comes over its surface; what we call life appears, and assumes many forms; at a point farther along in its course, life disappears, and the eternal river flows on regardless, till, at some other point, the same changes take place again. Life is inseparable from this river of energy, but it is not coextensive with it, either in time or in space.

In midsummer what river-men call "the blossoming of the water" takes place in the Hudson River; the water is full of minute vegetable organisms; they are seasonal and temporary; they are born of the midsummer heats. By and by the water is clear again. Life in the universe seems as seasonal and fugitive as this blossoming of the water. More and more does science hold us to the view of the unity of nature—that the universe of life and matter and force is all natural or all supernatural, it matters little which you call it, but it is not both. One need not go away from his own doorstep to find mysteries enough to last him a lifetime, but he will find them in his own body, in the ground upon which he stands, not less than in his mind, and in the invisible forces that play around him. We may marvel how the delicate color and perfume of the flower could come by way of the root and stalk of the plant, or how the crude mussel could give birth to the rainbow-tinted pearl, or how the precious metals and stones arise from the flux of the baser elements, or how the ugly worm wakes up and finds itself a winged creature of the air; yet we do not invoke the supernatural to account for these things.

It is certain that in the human scale of values the spirituality of man far transcends anything in the animal or physical world, but that even that came by the road of evolution, is, indeed, the flowering of ruder and cruder powers and attributes of the life below us, I cannot for a moment doubt. Call it a transmutation or a metamorphosis, if you will; it is still within the domain of the natural. The spiritual always has its root and genesis in the physical. We do not degrade the spiritual in such a conception; we open our eyes to the spirituality of the physical. And this is what science has always been doing and is doing more and more—making us familiar with marvelous and transcendent powers that hedge us about and enter into every act of our lives. The more we know matter, the more we know mind; the more we know nature, the more we know God; the more familiar we are with the earth forces, the more intimate will be our acquaintance with the celestial forces.