Time and Change.

by John Burroughs.

PREFACE

I suspect that in this volume my reader will feel that I have given him a stone when he asked for bread, and his feeling in this respect will need no apology. I fear there is more of the matter of hard science and of scientific speculation in this collection than of spiritual and aesthetic nutriment; but I do hope the volume is not entirely dest.i.tute of the latter. If I have not in some degree succeeded in trans.m.u.ting my rocks into a kind of wholesome literary bread, or, to vary the figure, in turning them into a soil in which some green thing or flower of human interest and emotion may take root and grow, then, indeed, have I come short of the end I had in view.

I am well aware that my own interest in geology far outruns my knowledge, but if I can in some degree kindle that interest in my reader, I shall be putting him on the road to a fuller knowledge than I possess. As with other phases of nature, I have probably loved the rocks more than I have studied them. In my youth I delighted in lingering about and beneath the ledges of my native hills, partly in the spirit of adventure and a boy's love of the wild, and partly with an eye to their curious forms, and the evidences of immense time that looked out from their gray and crumbling fronts. I was in the presence of Geologic Time, and was impressed by the scarred and lichen-coated veteran without knowing who or what he was. But he put a spell upon me that has deepened as the years have pa.s.sed, and now my boyhood ledges are more interesting to me than ever.

If one gains an interest in the history of the earth, he is quite sure to gain an interest in the history of the life on the earth. If the former ill.u.s.trates the theory of development, so must the latter. The geologist is pretty sure to be an evolutionist. As science turns over the leaves of the great rocky volume, it sees the imprint of animals and plants upon them and it traces their changes and the appearance of new species from age to age. The biologic tree has grown and developed as the geologic soil in which it is rooted has deepened and ripened. I am sure I was an evolutionist in the abstract, or by the quality and complexion of my mind, before I read Darwin, but to become an evolutionist in the concrete, and accept the doctrine of the animal origin of man, has not for me been an easy matter.

The essays on the subject in this volume are the outcome of the stages of brooding and thinking which I have gone through in accepting this doctrine. I am aware that there is much repet.i.tion in them, but maybe on that very account they will help my reader to go along with me over the long road we have to travel to reach this conclusion.

July, 1912.

TIME AND CHANGE

I

THE LONG ROAD

The long road I have in mind is the long road of evolution,--the road you and I have traveled in the guise of humbler organisms, from the first unicellular life in the old Cambrian seas to the complex and highly specialized creature that rules supreme in the animal kingdom to-day. Surely a long journey, stretching through immeasurable epochs of geologic time, and attended by vicissitudes of which we can form but feeble conceptions.

The majority of readers, I fancy, are not yet ready to admit that they, or any of their forebears, have ever made such a journey. We have all long been taught that our race was started upon its career only a few thousand years ago, started, not amid the warrings of savage elemental nature, but in a pleasant garden with everything needed close at hand. This belief has faded a good deal in our time, especially among thoughtful persons; but in a modified form, as the special creation theory, it held sway in the minds of the older naturalists like Aga.s.siz and Dawson, long after Darwin had launched his revolutionary doctrine of our animal origin, putting man in the same zoological scheme as the lower orders.

We are slow to adjust our minds to the revelations of science, they have been so long adjusted to a revelation, so-called, of an entirely different character. It gives them a wrench more or less violent when we try to make them at home and at their ease amid these new and startling disclosures. To many good people evolution seems an unG.o.dly doctrine, like setting up a remorseless logic in the place of an omnipresent Creator. But there is no help for it.

Science has fairly turned us out of our comfortable little anthropomorphic notion of things into the great out-of-doors of the universe. We must and will get used to the chill, yea, to the cosmic chill, if need be. Our religious instincts will be all the hardier for it.

When we accepted Newton's discovery of the force called gravitation, we virtually surrendered ourselves to the enemy, and started upon a road, the road of natural causation, that traverses the whole system of created things. We cannot turn back; we may lie down by the roadside and dream our old dreams, but our children and their children will press on, and will be exhilarated by the journey.

It is at first sight an unpalatable truth that evolution confronts us with, and it requires courage calmly to face it. But it is in perfect keeping with the whole career of physical science, which is forever directing our attention to common near-at-hand facts for the key to remote and mysterious occurrences.

It seems to me that evolution adds greatly to the wonder of life, because it takes it out of the realm of the arbitrary, the exceptional, and links it to the sequence of natural causation. That man should have been brought into existence by the fiat of an omnipotent power is less an occasion for wonder than that he should have worked his way up from the lower non-human forms. That the manward impulse should never have been lost in all the appalling vicissitudes of geologic time, that it should have pushed steadily on, through mollusk and fish and amphibian and reptile, through swimming and creeping and climbing things, and that the forms that conveyed it should have escaped the devouring monsters of the earth, sea, and air till it came to its full estate in a human being, is the wonder of wonders.

In like manner, evolution raises immensely the value of the biological processes that are everywhere operative about us, by showing us that these processes are the channels through which the creative energy has worked, and is still working. Not in the far-off or in the exceptional does it seek the key to man's origin, but in the sleepless activity of the creative force, which has been pushing onward and upward, from the remotest time, till it has come to full fruition in man.

It is easy to inject into man's natural history a supernatural element, as nearly all biologists and anthropologists before Darwin's time did, and as many serious people still do. It is too easy, in fact, and the temptation to do so is great. It makes short work of the problem of man's origin, and saves a deal of trouble.

But this method is more and more discredited, and the younger biologists and natural philosophers accept the zoological conception of man, which links him with all the lower forms, and proceed to work from that.

When we have taken the first step in trying to solve the problem of man's origin, where can we stop? Can we find any point in his history where we can say, Here his natural history ends, and his supernatural history begins? Does his natural history end with the pre-glacial man, with the cave man, or the river-drift man, with the low-browed, long-jawed fossil man of Java,--Pithecanthropus erectus, described by Du Bois? Where shall we stop on his trail? I had almost said "step on his tail," for we undoubtedly, if we go back far enough, come to a time when man had a tail. Every unborn child at a certain stage of its development still has a tail, as it also has a coat of hair and a hand-like foot. But could we stop with the tailed man--the manlike ape, or the apelike man? Did his Creator start him with this appendage, or was it a later suffix of his own invention?

If we once seriously undertake to solve the riddle of man's origin, and go back along the line of his descent, I doubt if we can find the point, or the form, where the natural is supplanted by the supernatural as it is called, where causation ends and miracle begins. Even the first dawn of protozoic life in the primordial seas must have been natural, or it would not have occurred,--must have been potential in what went before it. In this universe, so far as we know it, one thing springs from another; the sequence of cause and effect is continuous and inviolable.

We know that no man is born of full stature, with his hat and boots on; we know that he grows from an infant, and we know the infant grows from a fetus, and that the fetus grows from a bit of nucleated protoplasm in the mother's womb. Why may not the race of man grow from a like simple beginning? It seems to be the order of nature; it IS the order of nature,--first the germ, the inception, then the slow growth from the simple to the complex. It is the order of our own thoughts, our own arts, our own civilization, our own language.

In our candid moments we acknowledge the animal in ourselves and in our neighbors,--especially in our neighbors,--the beast, the shark, the hog, the sloth, the fox, the monkey; but to accept the notion of our animal origin, that gives us pause. To believe that our remote ancestor, no matter how remote in time or s.p.a.ce, was a lowly organized creature living in the primordial seas with no more brains than a shovel-nosed shark or a gar-pike, puts our scientific faith to severe test.

Think of it. For countless ages, millions upon millions of years, we see the earth swarming with life, low b.e.s.t.i.a.l life, devouring and devoured, myriads of forms, all in bondage to nature or natural forces, living only to eat and to breed, localized, dependent upon place and clime, shaped to specific ends like machines,--to fly, to swim, to climb, to run, to dig, to drill, to weave, to wade, to graze, to crush,--knowing not what they do, as void of conscious purpose as the thorns, the stings, the hooks, the coils, and the wings in the vegetable world, making no impression upon the face of nature, as much a part of it as the trees and the stones, species after species having its day, and then pa.s.sing off the stage, when suddenly, in the day before yesterday in the geologic year, so suddenly as to give some color of truth to the special creation theory, a new and strange animal appears, with new and strange powers, separated from the others by what appears an impa.s.sable gulf, less specialized in his bodily powers than the others, but vastly more specialized in his brain and mental powers, inst.i.tuting a new order of things upon the earth, the face of which he in time changes through his new gift of reason, inventing tools and weapons and language, harnessing the physical forces to his own ends, and putting all things under his feet,--man the wonder-worker, the beholder of the stars, the critic and spectator of creation itself, the thinker of the thoughts of G.o.d, the worshiper, the devotee, the hero, spreading rapidly over the earth, and developing with prodigious strides when once fairly launched upon his career. Can it be possible, we ask, that this G.o.d was fathered by the low b.e.s.t.i.a.l orders below him,--instinct giving birth to reason, animal ferocity developing into human benevolence, the slums of nature sending forth the ruler of the earth. It is a hard proposition, I say, undoubtedly the hardest that science has ever confronted us with.

Haeckel, discussing this subject, suggests that it is the parvenu in us that is reluctant to own our lowly progenitors, the pride of family and position, like that of would-be aristocratic sons who conceal the humble origin of their parents. But it is more than that; it is the old difficulty of walking by faith where there is nothing visible to walk upon: we lack faith in the efficiency of the biologic laws, or any mundane forces, to bridge the tremendous chasm that separates man from even the highest of the lower orders. His radical unlikeness to all the forms below him, as if he moved in a world apart, into which they could never enter, as in a sense he does, is where the difficulty lies. Moreover, evolution balks us because of the inconceivable stretch of time during which it has been at work. It is as impossible for us to grasp geological time as sidereal s.p.a.ce. All the standards of measurement furnished us by experience are as inadequate as is a child's cup to measure the ocean.

Several million years, or one million years,--how can we take it in?

We cannot. A hundred years is a long time in human history, and how we pause before a thousand! Then think of ten thousand, of fifty thousand, of one hundred thousand, of ten hundred thousand, or one million, or of one hundred million! What might not the slow but ceaseless creative energy do in that time, changing but a hair in each generation! If our millionaires had to earn their wealth cent by cent, and carry each cent home with them at night, it would be some years before they became millionaires. This is but a faint symbol of the slow process by which nature has piled up her riches.

She has had no visions of sudden wealth. To clothe the earth with soil made from the disintegrated mountains--can we figure that time to ourselves? The Orientals try to get a hint of eternity by saying that when the Himalayas have been ground to powder by allowing a gauze veil to float against them once in a thousand years, eternity will only have just begun. Our mountains have been pulverized by a process almost as slow. In our case the gauze veil is the air, and the rains, and the snows, before which even granite crumbles. See what the G.o.d of erosion, in the shape of water, has done in the river valleys and gorges--cut a mile deep in the Colorado canyon, and yet this canyon is but of yesterday in geologic time. Only give the evolutionary G.o.d time enough and all these miracles are surely wrought.

Truly it is hard for us to realize what a part time has played in the earth's history,--just time, duration,--so slowly, oh, so slowly, have the great changes been brought about! The turning of mud and silt into rock in the bottom of the old seas seems to have been merely a question of time. Mud does not become rock in man's time, nor vegetable matter become coal. These processes are too slow for us. The flexing and folding of the rocky strata, miles deep, under an even pressure, is only a question of time. Allow time enough and force enough, and a layer of granite may be bent like a bow. The crystals of the rock seem to adjust themselves to the strain, and to take up new positions, just as they do, much more rapidly, in a cake of ice under pressure. Probably no human agency could flex a stratum of rock, because there is not time enough, even if there were power enough. "A low temperature acting gradually,"

says my geology, "during an indefinite age would produce results that could not be otherwise brought about even through greater heat." "Give us time," say the great mechanical forces, "and we will show you the immobile rocks and your rigid mountain chains as flexible as a piece of leather." "Give us time," say the dews and the rains and the snowflakes, "and we will make you a garden out of those same stubborn rocks and frowning ledges." "Give us time," says Life, starting with her protozoans in the old Cambrian seas, "and I will not stop till I have peopled the earth with myriad forms and crowned them all with man."

Dana thinks that had "a man been living during the changes that produced the coal, he would not have suspected their progress," so slow and quiet were they. It is probable that parts of our own sea-coast are sinking and other parts rising as rapidly as the oscillation of the land and sea went on that resulted in the laying down of the coal measures.

An eternity to man is but a day in the cosmic process. In the face of geologic time, man's appearance upon the earth as man, with a written history, is something that has just happened; it was in this morning's paper, we read of it at breakfast. As evolution goes, it will not be old news yet for a hundred thousand years or so, and by that time, what will he have done, if he goes on at his present rate of accelerated speed? Probably he will not have caught the G.o.ds of evolution at their work, or witnessed the origin of species by natural descent, these things are too slow for him; but he will certainly have found out many things that we are all eager to know.

In nature as a whole we see results and not processes. We see the rock strata bent and folded, we see the whole mountain-chains flexed and shortened by the flexure; but had we been present, we should not have suspected what was going on. Our little span of life does not give us the parallax necessary. The rock strata, miles thick, may be being flexed now under our feet, and we know it not. The earth is shrinking, but so slowly! When, under the slow strain, the strata suddenly give way or sink, and an earthquake results, then we know something has happened.

A recent biologist and physicist thinks, and doubtless thinks wisely, that the reason why we have never been able to produce living from non-living matter in our laboratories, is that we cannot take time enough. Even if we could bring about the conditions of the early geologic ages in which life had its dawn, which of course we cannot, we could not produce life because we have not geologic time at our disposal.

The reaction which we call life was probably as much a cosmic or geologic event as were the reactions which produced the different elements and compounds, and demanded the same slow gestation in the womb of time. During what cycles upon cycles the great mother-forces of the universe must have brooded over the inorganic before the organic was brought forth! The archean age, during which the brooding seems to have gone on, was probably as long as all the ages since.

How we are baffled when we talk about the beginning of anything in nature or in our own lives! In our experience there must be a first, but when did manhood begin; when did p.u.b.erty, when did old age, begin? When did each stage of our mental growth begin? When or where did the English language begin, or the French, or the German? Was there a first English word spoken? From the first animal sound, if we can conceive of such, up to the human speech of to-day, there is an infinite gradation of sounds and words.

Was there a first summer, a first winter, a first spring? There could hardly have been a first day even for ages and ages, but only slowly approximating day. After an immense lapse of time the air must have cleared and the day become separated from the night, and the seasons must have become gradually defined. Things slowly emerge one after another from a dim, nebulous condition, both in our own growth and experience and in the development of the physical universe.

In nature there is no first and last. There is an endless beginning and an endless ending. There was no first man or first woman, no first bird, or fish, or reptile. Back of each one stretches an endless chain of approximating men and birds and reptiles.

This talk about the time and place where man began his existence seems to me misleading, because it appears to convey the idea that he began as man at some time, in some place. Whereas he grew. He began where and when the first cell appeared, and he has been on the road ever since. There is no point in the line where he emerged from the not-man and became man. He was emerging from the not-man for millions of years, and when you put your finger on an animal form and say, This is man, you must go back through whole geologic periods before you reach the not-man. If Darwin is right, there is no more reason for believing that the different species or forms of animal life were suddenly introduced than there is for believing that the soil, or the minerals, gold, silver, diamonds, or vegetable mold and verdure were suddenly introduced.

II

If we know anything of the earth's past history, we know that the continents were long in forming, that they pa.s.sed through many vicissitudes of heat and cold, of fire and flood, of upheaval and subsidence--that they had, so to speak, their first low, simple rudimentary or invertebrate life, that they were all slow in getting their backbones, slower still in clothing their rock ribs with soil and verdure, that they pa.s.sed through a sort of amphibian stage, now under water, now on dry land, that their many kinds of soils and climes were not differentiated and their complex water-systems established till well into Tertiary times--in short, that they have pa.s.sed more and more from the simple to the complex, from the disorganized to the organized. When man comes to draw his sustenance from their b.r.e.a.s.t.s, may they not be said to have reached the mammalian stage?

The fertile plain and valley and the rounded hill are of slow growth, immensely slow. But any given stage of the earth has followed naturally from the previous stage, only more and more and higher and higher forces took a hand in the game. First its elements pa.s.sed through the stage of fire, then through the stage of water, then merged into the stage of air. More and more the aerial elements--oxygen, carbon, nitrogen--have entered into its const.i.tuents and fattened the soil. The humanizing of the earth has been largely a process of oxidation. More than disintegrated rock makes up the soil; the air and the rains and the snows have all contributed a share.

The history of the soil which we turn with our spade, and stamp with our shoes, covers millions upon millions of years. It is the ashes of the mountains, the leavings of untold generations of animal and vegetable life. It came out of the sea, it drifted from the heavens; it flowed out from the fiery heart of the globe; it has been worked over and over by frost and flood, blown by winds, shoveled by ice, --mixed and kneaded and moulded as the house-wife kneads and moulds her bread,--refining and refining from age to age. Much of it was held in solution in the primordial seas, whence it was filtered and used and precipitated by countless forms of marine life, making a sediment that in time became rocks, that again in time became continents or parts of them, which the aerial forces reduced to soil. Indeed, the soil itself is an evolution, as much so as the life upon it.

We probably have little conception of how intimate and cooperative all parts of the universe are with one another,--of the debt we owe to the farthest stars, and to the remotest period of time. We must owe a debt to the monsters of Mesozoic and Caenozoic time; they helped to fertilize the soil for us, and to discipline the ruder forces of life. We owe a debt to all that has gone before: to the heavens above and to the earth-fires beneath, to the ice-sheets that ground down the mountains, and to the ocean currents. Just as we owe a debt to the men and women in our line of descent, so we owe a debt to the ruder primordial forces that shaped the planet to our use, and took a hand in the game of animal life.

The G.o.ds of evolution had served a long apprenticeship; they had gained proficiency and were master workmen. Or shall we say that the elements of life had become more plastic and adaptable, or that the life fund had acc.u.mulated, so to speak? Had the vast succession of living beings, the long experience in organization, at last made the problem of the origin of man easier to solve?