THE LAPSE OF TIME.
The divergence of opinion between scientific and unscientific persons is scarcely anywhere more conspicuous than in their measurements of the age of the world we live in. A popular impression still prevails that the old beldame earth, as Hotspur calls it, is about six thousand years of age. A little margin is sometimes allowed. By an exercise of heroic liberality a period of ten or twelve thousand years is occasionally conceded for the earth’s existence. Any chronology discontented with these ample limits comes within the domain of rash and dangerous speculation. Some, indeed, who would fain conciliate all parties, are willing to extend the bounds on certain conditions. They will grant a large extra slice of time, provided that during that period the earth was a shapeless uninhabited lump, or if inhabited, not inhabited by men. ‘Come, now,’ says the cheap-jack, ‘I’ll tell you what I’ll do with you; I’ll throw you in another five thousand years; fifteen thousand years! and take the lot. What! not do? I’ll make it twenty thousand. Now, I’ll tell you what I’ll do with you: I’ll make it five-and-twenty thousand years, and if that won’t satisfy you, you aren’t worth arguing with.’
What scientific men think of the cheap-jack’s offer it is the object of this essay to consider.
The problem upon which many thoughts and speculations of science are for the moment converging is the origin of life. There are some who believe that under certain chemical conditions living creatures are continually coming into existence, ungenerated by any living parent, born as it were without birth, acquiring an animated existence, with powers of motion, feeding, and reproduction, from substances previously wanting in one or all of these capacities; such creatures, in short, as, if asked for their parentage, could but answer, each for itself, my father was an atom, and my mother a molecule. It should be remembered that the little animals supposed to arise in the manner described first become visible, if at all, as the tiniest objects that microscopes can detect. But whether there is or is not in these days a continual coming into existence of these infinitesimal pigmies, they are just such productions as the Theory of Development would suppose to have arisen originally, constituting the first outburst of life upon the globe, ancestral to the noblest forms of animated nature now extant, progenitors in an unbroken line of man himself. As a rule, among living things we find that offspring bear a tolerably exact resemblance to their parents. The lower the organism the less easy is it to distinguish specimens of one generation from those of another; and even in the most highly organized creatures the points of resemblance generally far outweigh the points of difference between the parents and their children. In short, under ordinary circumstances, not one generation only, but a hundred, may pass away without registering any perceptible alteration in the character of a species. A hundred generations of mankind would require a period of about three thousand years. A hundred generations of less important creatures might not perhaps require even as large a number of hours. But between the two extremes the necessary periods would bear a kind of ratio to the perfection of the organism. Variations might now and then follow one another in quick succession, and then a pause come of a thousand generations or so before any further changes in the character of a species.
Such are the conditions under which Mr. Darwin and his followers believe it possible for the whole sequence of changes to have been effected, which have ended in peopling the whole earth with a countless variety of the most diverse forms of life. Many persons are horrified at the notion of linking together a man and a monkey even by the most distant ties of consanguinity; what will they say to a genealogy which begins with an almost invisible speck and ends with a Patagonian giant—a genealogy which asserts that, through the slow process of minute changes occurring for the most part at rare intervals, our fair humanity has been developed or evolved out of creatures which no unaided human eye could distinguish from the dust on which we carelessly trample. To some ears such a theory must sound wild and preposterous beyond all the boundaries of sane and rational thinking. And, in truth, no censure could be too severe, no ridicule too keen for so extravagant a piece of folly as this theory must be, if the old and still prevailing notions about the age of the world have any foundation in fact. It only begins to be reasonable, if we can afford to stretch our notions of history from the narrow margin of six thousand to the broader field of six hundred thousand years, with an indefinite past in the background.
This vast lapse of time, as commensurate with the existence of the inhabited globe, is essential to the Theory of Development. It must be established, as it has been, by independent evidence of its own, before it can give to that theory its absolutely necessary support. But the Theory of Development in its turn helps the mind to believe and realize this enormous lapse of time, with its seemingly never-ending march and flow, rank upon rank, wave upon wave, by finding work and employment for all its almost measureless duration. It explains, as it were, why the drama of life still goes on, why the play was not long ago played out, and the curtain let fall upon all the busy multitudinous actors.
Time of itself does nothing; but nothing can be done without time. It is not a personal agent, but a necessary condition. We cannot even think, much less reason, of things as occurring out of time and independently of it, any more than we can think or reason of matter as existing independent of space. Every occurrence takes time: and yet we may not leap from this fact to the conclusion that a countless multitude of occurrences will require a vast duration of time. Professor Tyndal, in his Lecture on the Scientific Use of the Imagination, refers to waves of light less than 1/50000 of an inch in length. How many do you suppose of such waves would be required to compass a mile? How many to accomplish the 185,000 miles which light travels in a second? Each undulation is a separate occurrence, so that we have millions of millions of occurrences following one upon another in a second of time. In studying, therefore, the complete fabric of the globe, or even of the whole material universe as far as it comes within our ken, the problem for solution is not whether these great results could or could not have been brought to pass in an indefinitely short space of time, in the twinkling of an eye, as one might say, but whether the space of time employed in their production has actually and in fact been indefinitely short or indefinitely long. We ought also to bear in mind that the terms we use when we speak of long and short, are relative not absolute—relative to the duration of our own lives, or to some other arbitrary standard which we are pleased to set up for purposes of comparison. Thus a year is long compared with a minute, but short compared with a millennium; a thousand years would be an enormous length for the life of a mortal man, but compared with the ceaseless flow of ages, which we call eternity, this same thousand years becomes, as it were, an imperceptible speck, less than a drop of water compared to the Atlantic, a point of time so inconceivably minute, that no human mind could grasp it as an intelligible unit of measurement. For time, we have an inexhaustible past on which to draw. Against any given theory of production, no objection pure and simple that the theory makes too large a demand upon time, can be maintained. An objection, to be valid against the existence of life on the earth a million of years back, must postulate that there was no earth then in existence, or none capable of supporting life; for if we choose to stand by the doctrine of final causes, life upon the earth must have begun as soon as life upon the earth was possible, otherwise we should have a fair and perfect design with its purpose unaccomplished; or, if we prefer the Theory of Development carried out to its legitimate consequences, equally must we admit, that as soon as the earth was fitted for living creatures, living creatures would be generated upon it.
In tracing back the duration of the globe, the first demand of the uninitiated will be for the written evidence of historical records. The popular impression claims to be founded upon such evidence of the most authoritative description. Little do the upholders of this impression in general understand that they are building their faith, not upon the Book of Genesis, or the inspiration of the Hebrew lawgiver, but on the arithmetical speculations of an Irish archbishop, who lived in the seventeenth century.
Before we can accept the Hebrew genealogies as competent data for historical chronology, we must understand the principles on which they were framed. In ancient languages we have abundant evidence to show that the ties of blood were not as sharply distinguished as among ourselves. The same word sufficed to designate son and grandson, and even the most remote descendant. A man’s heir was called his son; an usurping successor might receive the same title[43]; and, beyond all this, it has been shown to have been ‘a common practice with the Jews to distribute genealogies into divisions, each containing some favourite or mystical number; and that, in order to do this, generations were either repeated or left out.’ Some persons, perhaps, will say, ‘We don’t believe it, or we don’t believe it in regard to any of the biblical genealogies.’ And yet the very first chapter of the New Testament is the most conclusive and incontrovertible proof of the statement; for our Lord’s genealogy[44] is there expressly divided into three periods of fourteen generations each, and the middle period has been stripped of three generations in order to bring it down to the pre-determined number. The names of three well-known princes (Ahaziah, Joash, Amaziah), whose histories occupy several chapters in the Second Book of Kings, are omitted, and Amaziah’s son is described, without further note or comment, as a son begotten by one who was really his father’s great-grandfather. In a matter so obvious, there cannot attach to the compiler of the genealogy the very faintest suspicion of bad faith. He was following the custom of his country, for reasons then deemed, and perhaps in those days actually being, good and sufficient. Can we make as satisfactory an apology for men in the present day, who shut their eyes to the nature of the evidence on which they build opinions about the age of the world opposed to the discoveries of science? If in the first century of the Christian era, in times of comparative enlightenment, by men of approved truth and uprightness, genealogies could be compiled without the smallest regard being paid to the actual number of successive generations, it becomes impossible to attach any value as chronological evidence to Hebrew genealogies fifteen hundred, or, for all that we can tell, fifteen thousand years more ancient. Had the genealogy on which this conclusion rests admitted a chance of error, had there been any motive for fraud in its construction, did any suspicion lie against its authenticity, the case would be weakened. But just because there neither was nor could have been error in the mind of the writer, or deceit in his intention, just because what he wrote, he wrote deliberately and of set purpose, it is certain that his record is not, and was never meant to be, a measure of time; and that those who persist in measuring time by similar records, are the victims of a manifest delusion, ensnared, it may be feared in too many cases, with their eyes open.
There is an old jest that, in the pride of antiquity, a Welshman generally traces back his lineage not only as far as Adam, but a great deal further. Nothing was easier, before the age of historical criticism, than for men or nations, whose real origin was lost in obscurity, to link their names to an illustrious past. Nothing was easier than to develope the obscurity itself into a long line of remote ancestors, whose names and virtues could be invented and multiplied at pleasure. What the poet was only too willing to imagine, the mathematician seemed able to confirm, by registering astronomical occurrences in far-distant long-past ages with as much precision as those which he predicted, and predicted truly, for his own and future times. The Hindoo chronology reckons the age of the world by millions of years. The Egyptians twenty centuries ago used to tell of 330 kings of whom they knew no more than the names. There were Greeks who claimed to be older than the moon; others who anticipated the theory of abiogenesis by claiming to be sprung from the earth itself without the intervention of parents; and yet others, who with more modesty or more pride, as we please to regard it, derived their origin from gods and demigods. None were willing to be thought new people. The man of yesterday, the novus homo, the upstart, the parvenu, has ever been disliked and laughed at by society. And in like manner, among nations, a new rival excites the fears and encounters the ridicule of the established clique. Claims to antiquity, therefore, were as advantageous to possess as they were easy to forge. Those that have been mentioned, being unattested by any corroborative facts, and, where they are not obviously false, being unsusceptible of proof, are worthless in themselves. One thing they tend to show, namely, that all remembrance of the real origin of mankind, and of the date of that origin, had been absolutely lost to those ancient peoples. From over the sea, from beyond the mountains, from the bright east or the frozen north, they might know that their forefathers had made pilgrimage in distant ages—or they might know of no time, however far back, when the seat of their habitation had not been occupied by their own progenitors. In either case their ignorance of primeval history is as absolute as it is conspicuous. One prevailing tradition, it is true, is current alike in sacred and profane literature, of a far-off golden time, an age of simplicity, when man conversed with the beasts of the field, when the earth brought forth her fruits spontaneously, with her bosom as yet unvexed by the ploughshare, ere the knowledge or the discrimination of good and evil had come into the world—the record, in one word, as all these details tend to prove, of a time before man had become a moral being; a dim mysterious recollection, almost like a dream, of a time before the animal nature had been decisively exalted into humanity.