A Thought and Its Thinkers

THE REVELATION OF EVOLUTION

BY PERCIVAL LOWELL

A MASTER-THOUGHT lives always; it speaks forever in the echoes it evokes. We honor its conception as the Romans did Minerva sprung from the head of Jove. In it its thinker immortally lives on. For its birth we still remember long after the man himself is dead, and it is to celebrate one such centenary that so many meetings have this year been held. Yet, amid the resounding plaudits, few perhaps were conscious of what it was they cheered, nor among mankind’s conceptions how Darwin’s stood related to the rest. For the origin of species is as much a mystery as ever; it was for bringing animate existence within universal law that Darwin’s memory is kept. It was as part of cosmogony’s master-key that the thought that led to its unlocking was great. For in truth the rise of the organic is but the latest chapter in a serial of the sky. It is the culmination to the present hour of a long preparatory career. Though for us not the least important item of our world’s eventful history, the space it fills is brief beside the æons through which the prefatory process stretches back into the past. Threading the shorter and the long alike, a single causal chain binds both into an articulated whole : the principle of evolution.

Evolution is nothing more nor less than the mainspring of the universe. Grand in its simplicity, it is the one fundamental fact on which all we know depends. From its influence nothing can escape; for it has fashioned everything, from nebula to man. To appreciate it is to recognize that the universe was not made from without, but grew to be what it is from within. Not a mechanism cunningly contrived, the cosmos is an organism that includes both you and me.

In view of the simplicity, the universality, the importance of the fact, the surprising thing is that it should have escaped most men’s recognition so long. For we find it through the ages realized only by the master minds. Considering that man stands confronted by instances of it from his cradle to his grave, one is tempted to believe that the sole object exempt from its working, the one thing incapable of intelligent advance, is the mind of man himself. Certainly his selfbestowed title of homo sapiens can be only by brevet, a hoped-for honor to which so far he has but carieaturally attained. Quickness of apprehension is not his most marked trait, or he would surely have suspected the sarcasm of his scientific name. Yet, considered from the standpoint of evolution, the situation is perhaps all one could expect. Trial and error must needs have taken long to get him where he is.

Pushed or prompted from the forest, primeval man stood ushered on the plains. With the opening of the prospect thus presented him, began the widening of the horizon of his mind. Through this, as much as anything, he parted company from the brutes. Search for subsistence led him to wander, and his wanderings lured perception to journeys farther still. Alone with his flocks at night on the wide Chaldean steppes, his thoughts perforce gravitated to the stars. Something beyond the Earth swam into his ken as he sat and watched them swing silently overhead. Not less was such communion furthered through his voyages by sea. Already the stellar courses must have been well known when the Phœnicians pushed boldly out into the broad expanse of the Mediterranean, to be guided by the Sun by day, by the constellations by night. Homer enumerates the asterisms they steered by, and it argues no mean familiarity with the heavens that they dared to be thus piloted, no matter what the season of the year.

So much of knowledge led to more. We may even trace its source. Mnesarchus, the father of Pythagoras, is said to have been a Tyrian merchant, who settled finally in Samos; and it was doubtless from sailing with him out of sight of land, through the long, cold winter nights, steering by the stars, that the boy’s thoughts were turned to thinking what they meant — to better purpose than is commonly supposed. For the higher minds among the ancient Greeks reached marvelously correct ideas of the structure of the universe, considering their instrumental means. Five centuries before Christ, Pythagoras was cognizant that the Earth turned on her axis and revolved about the sun; and his doctrines, written out and extended by his follower Philolaus, were handed down in secret, for fear of priestcraft, through the centuries that followed. Debased on purpose for exposition to the people, the memory of the truth was lost, and so it came about that that arch-mediocrity, Ptolemy, imposed upon the world, to dominate it for more than a millennium, a false earth-centred astronomy by means of an imposing book.

The idea of evolution, too, had entered the keen Greek mind. Anaximander (611 to 545 B. c.) taught that from a vast unbounded body evolved a central mass, our earth ; and out of the earth came life. Man, himself, he supposed had sprung from other animals, probably marine. Anaxagoras (450 B.c.) conceived motion to be the ruling spirit, and minute particles of things to have been gradually segregated to their present state. Cold played a part in this, and animals sprang from out the earth’s aboriginal moist clay. In Empedocles’s scheme we find spontaneous variation and the eventual survival of the fittest. While Lucretius, in his great epic on the Nature of Things, in which that brilliant poet-scientist resumed the learning of his foretime on the subject, says appositely (Book V, 826-827) that the earth spontaneously brought forth life, ceasing only when she passed the bearing age. Thus did the ancients strangely adumbrate the truth. Their cosmologic building differed from that of later ages chiefly in the character of the bricks. For the physical laws on which all such structures must be founded had not yet been found.

Then the long night of the middle ages settled down on man, when thought itself was blotted out. Nor did the idea of evolution come in with the dawn again of learning. Intellectually, men began anew, and took things as ready-made as a child his toys. Even the discoverer of the law of gravitation saw interposition in the orderly arrangement of the planets, from which the comets had been left exempt, and foresaw further interposition necessary to keep them going in the future. He tells us so very explicitly in his general scholium at the end of the Principia.

It was not till the middle of the seventeenth century of our era that the idea that the universe had evolved seems again to have occurred to man.

Descartes (1744) led speculation with his theory of vortices, the sun and planets being due to swirls in a continuous medium pervading space. It was accepted for twenty years or more by the best minds of the day, — Leibnitz, Huygens, and the like, — to be finally demolished by Newton. A century later, Kant devised another origin for the solar system. It might have been superb had Kant’s knowledge of physics equaled his divining sight. He conceived a primal nebula, originally at rest, to have given birth to the sun and his cortège by the falling together of its parts, a self-acquired vitality of movement we now know to be as vain as the attempt to lift one’s self bodily by one’s bootstraps. To be commended for its daring, though, this bold modern driving of the chariot of the sun!

To Laplace, a generation later, is due the first truly scientific attempt at explanation. For it is one thing to perceive that the solar system must have grown to its present state, as a boy grows, by a development intrinsic to itself, and another to point out the actual steps of the process. Laplace in 1796, in his Exposition of the System of the Universe, advanced a cosmogony, with the reserve of a great mathematician who realized that observation and calculation alone can give certainty of result, which dominated scientific thinkers for three-quarters of a century. At the time it was published it seemed to account for the then known facts.

Laplace supposed a pristine nebula, tenuously vast, which rotated as an articulated whole because of friction between its parts. Contracting under its own gravity, it spun faster as it condensed, till its outer parts attained such speed that they reached the limit of abandonment, and a ring was left behind. Withdrawing farther, another ring was ultimately detached, and so the process went on, each ring separating in due order of distance from the sun. These gathered upon themselves to form the planets, which, still contracting and twirling faster as they shrank, threw off their satellites in turn. A grand conception for its simplicity, but too simple to be true. The advance of science since has disclosed some fatal flaws in it, which have obliged its giving up. First: the necessary friction for such solidarity of movement is not in nature. Substitutes for this have since then been devised, but unavailingly, to save the Laplacian idea, for other flaws in it are irremediable. The solar system is not as uniform in plan as then was thought. Especially must the comets be accounted for. Laplace expressly accepted them, for he considered he had proved them unattached visitors from other stars. Two errors caused him thus to think : one, a mathematical mistake first pointed out by Gauss; the other, the overlooking the sun’s motion through space. He believed he had shown that the orbits of the comets were such as should mathematically be expected, did those bodies come to us from without. But in the course of his analytic transformations he had taken as convergent a series which in reality was not, and his formulæ had been vitiated in consequence. Gauss detected and exposed the fallacy; then, later, Schiaparelli wrote a paper showing, on other lines, that the comets must be deemed our own; and lastly Fabry of Marseilles, in a masterly memoir not sufficiently known, has demonstrated that were the comets not members of our solar system, hyperbolic, or unclosed, orbits among them should be very common, not one of which for certain has ever been observed.

That the precise manner of the cosmos’ growth escaped its first investigator is not strange, as it has more or less eluded every thinker since who has tried to trace it. Yet, by standing on the shoulders of those who went before, each generation has peered a little farther back into the past. New acquisitions in physics, though disproving hypotheses once held, have led us by so much nearer to the truth. Its history is the chronicle of the mind’s most brilliant march, which had been more than human had it not been cumbered by mistake. To miss the road at times does not preclude an eventual reaching of the goal. For science is not a chain of disconnected, successively discarded beliefs, as is sometimes popularly supposed, but itself a development growing to greater generality, and so to truth, as its horizon spreads. It is itself the archetype of what it seeks to solve.

More has now to be explained than Laplace envisaged. Thus comets, now known to be part and parcel of the solar system and vagrants from interstellar space, demand recognition in any evolutionary scheme. Other intruding autochthones too, undiscovered a century ago, insist on disturbing the harmony of the Laplacian plan. Unconforming members, these, that cannot be ignored. It is in its outer parts that the system shows thus different and complex. The distant planets do not rotate in like sense with the near ; while their satellites all retrograde. Then, too, the last-found satellite of Saturn, and that of Jupiter as well, move contrariwise from what their sisters do. Significant it is that it should always be the system’s peripheral parts that differ from the main. Kirkwood, Roche, Trowbridge, Faye, Ligondés, and others, have met these difficulties singly or en bloc by explanations more correct than compelling. For in so many-elemented a matter the might be is other than the must. One vera causa has certainly been acquired, not subversive of, but supplementary to, what went before. For a previously unreckoned factor is tidal evolution. We owe its recognition to one almost unknown while he was living, the brilliant Edouard Roche. Ancillary, not all-directing, it has helped shape the system to its present state. At the hands of Sir George Darwin, the eldest son of the great naturalist, it has made the moon hint us the story of its birth ; and at those of See, it speaks of the genesis of double stars. Certain it is that the system bears evidence of this action in the countenance it presents. Just as the moon shows us always the same face, so Mercury and Venus we now know turn one side in perpetuity to the sun, and the best seen satellites of the other planets seem to do the like to their cynosural lords. Tidal friction this bespeaks. To this cause, too, may the planets’ axial tilts, progressing from inversion to uprightness as one comes inward to the sun, in all probability be ascribed, as Kirkwood first pointed out (1864).

Without attempting here a picture of what probably took place, let me sketch a line or two of its reconstruction as they have taken shape at midnight to one watcher of the stars. Strange to say, perhaps the latest news about our solar family has come from the smallest and most seemingly insignificant of its members. It is just because they are the simplest of its constituents and the least developed that they bear witness so well. Ask the children of a household, not their elders, if you want domestic facts. These little telltales are the meteorites, the stones which fall from heaven from time to time. Shrewdly questioned, these bits of meteoric stone and iron have a most surprising story to unfold, a tale which stretches so far back into the past as to stagger thought, and yet so fresh in their embalming of it as to seem of yesterday. Their speed and their great numbers show that they are cosmic bodies like the planets themselves, the unswept-up remnants, in fact, of what once strewed space, and out of which the planets were formed. They are thus parts of the primal nebula.

But important as this is, it is not all. Through the strange fretwork of their face, like the frosting of the cold of space upon the window-pane of time, we gaze upon a state of things antedating that nebula itself. For their Widmanstättian figures betray a constitution different from any known on earth. Most nearly kin to our deep minerals, their character and speed proclaim them as once part of some great solid globe placed where our sun now is, which at one time had itself been hot, and subsequently cooled. Fragments now, scattered orphanwise in space, they speak mutely of their parentage, and of the mighty cataclysm in that body whose shattering gave them birth. Parts of what went before, parts too of what is to-day, they are themselves the link in our chain of evidence connecting the present with the past, proving how we came to be. They are the tangible realization of what the philosophic seers saw with the mind’s eye down the far vista of recalled time. Had any one told Laplace that man would ever hold and handle parts of the very nebula from which we sprang, surely no one would have been more surprised than he.

From the information afforded us by meteorites we turn to another discovery of recent date, the recognition of the spiral nebulæ. So-called for their striking structure, they are also known as white for their spectroscopic look. Known for long in some few instances, it is their overwhelming commonness which has lately been descried. For they prove to constitute by far the greater number of all the nebulæ in the sky, and are sharply differentiated from the other class, the irregular or green. To them there is reason to believe all intermediate forms belong; the ring nebulæ being in reality spiral, and the planetary nebulæ too, types both of the same process reduced to its lowest terms. Their structure speaks unmistakably of evolution, and their universality proclaims such evolution to be the inevitable procedure of the universe.

Their color, white, arises from their showing a continuous spectrum, and indicates that they are composed in large part at least of solid particles, whereas the green tint of the others comes solely from glowing gas. Now, this spectrum is just what they should show were they flocks of meteorites, — and such they undoubtedly are. They give us, therefore, the second chapter of the evolutionary history. For, from their peculiar structure, we can infer what the process was that scattered the constituents of the once compact ball whose existence the meteorites attest. They consist of a central core from which two spiral coils unfold, the starting-point of the one diametrically opposite the other. Now this is what would happen had the original mass been tidally disrupted by a passing tramp. Tides in its body would be raised toward and opposite the stranger, and these would scatter its parts outward; the motion due the tramp combining with the body’s spin to produce the spiral coils we see. Just as in the meteorites we have found the substances from which our solar system rose, so in these nebulæ we see an evolution actually in process which may have been our own.

Turning now to our solar system, we mark in it arrangements which cannot be the result of chance. An orderly disposition in the motions of its parts shows that it evolved according to definitely acting laws. In some we can trace their action analytically, in some it still remains hidden from our ken. But we already know enough to be sure that the system grew to be what it is, not that it arose as such. Every year adds something to help to point its path. Not simply the disposition of the motions, but a disposal of the masses in it has recently been recognized — a disposal so peculiar that it calls for a mechanical basis, which we shall some day find. On this, as on other signposts of the course it took to fashion the orderly arrangement we today behold, space forbids my dwelling.

But the nebular hypotheses of mechanics are only the outer portals and broad avenues of evolution. They leave us on the threshold of where the greatest, because the most intrinsic, interest begins : that strange development by which the inorganic grew into the organic by due process of change. To Lockyer we owe its far-off preface-reading in the chemistry of the stars. The dissociation of matter he thought to mark in the hottest of these suns is the point at least from which evolution set out. His detailing of the process has not indeed proved true, but his suggestion of how and where to look for it is not by that impaired. Just as the real nebula was not as Laplace supposed, so with Lockyer’s dissociation of elements in the stars. Matter may not be resolvable in the manner that he thought, but that evolution is the inevitable concomitant of the process of cooling down, everything testifies to be the fact.

Coming earthward from the stars, we can mark this causal cooling through the whole range of evolutionary development. One stage of it we see in the present constitution of the sun; another in its retinue of worlds. In our great hearth-fire all substances are in their elemental state. It is too hot there for chemical affinity to act. In the major planets, where the heat is less, compounds have begun to form, but compounds of which we have no counterpart on earth. We note them by their unknown spectral bands, so beautifully brought out by Slipher, and we think they must be compounds as we miss them in the stars. In our own world, where it is colder still, chemical combination has advanced yet further, and has been doing so increasingly since the earth began to cool. In the record of the rocks we read of eras when only the inorganic could exist. Then, as that same history reveals, the greater intricacy of the organic molecule became possible through the tempering of its habitat. The step was taken which seems to us so great but was in fact so small, the waking of the molecule to life. That its beginnings cannot be reproduced in laboratories to-day is because the conditions that evolved them have themselves changed, and those conditions are well-nigh impossible of recall. In Lucretius’s words, our mother is now too old. Nevertheless, as Professor Jaggar has suggested, volcanoes, hot springs and their surroundings, the dying-out conditions of the primeval world, are the place to look for such instructive atavism to-day; and there possibly a clue to it may yet be found. Meanwhile noteworthy experiments by Burke, with radium on gelatinous films in sterilized tubes, have led to growths singularly simulative, to say the least, of the reality; while still other very remarkable researches by Bose upon the responsiveness of metals, plants, and animals, go in another way to demonstrate them kin.

Just as researches on this earth all point to the bringing forth of life by a planet as the necessary outcome of its own career, provided its physical condition be right, so has investigation in the sky. From our island home in space we may peer across to other islands voyaging through the void, and by telescopic help mark what there is going on. In very different stages we find them, of their own evolutionary career. Such diversity of itself attests a general development, for on no two were either the beginnings or the course the same. Some are youthful, some are old; some were fairly like us at the start, some fundamentally diverse. Only where conditions are roughly similar could we expect to behold anything familiar, and even there it would not be the same. All the more compelling if we find evidence of the oneness of the whole. Now, within the last few years, research has brought to light testimony that our nearest of solar kin has had its organic history too. Upon the planet most likely to support such existence at the present moment, other than ourselves, study has disclosed features which cannot be explained except as evidence of transplanetary life. Pregnant with thought this is, for it brings corroboration of the whole evolutionary process from beyond the confines of our native earth. That the inorganic should develop into the organic on a single planet might perhaps be accidental, but not on two. From Mars comes the cosmic assurance that it is Nature’s law.

When now in retrospect we contemplate this growing recognition of the universe’s march, two thoughts come to us together; one of admiration, the other of surprise. For a certain grandeur possesses us at the thought of man’s perception stretching out into the vastness of space, and by it being carried into the immensity of time. Man! whose little life is rounded out by three-score years and ten, and whose tenantable domain is the film-like cuticle of this small earth; an inheritance shrinking, like Balzac’s Peau de Chagrin, year by year through his enjoyment of it. For steadily he is diminishing his supply: exterminating its simpler denizens, deforesting it of trees, and crowding it continuously more and more. That man, whose ancestors entered on all fours, should at last look up, then look before, and ultimately beyond, has in it force to fire imagination and clothe him with something close of kin to immortality.

Side by side with this is the wonder that his awakening took so long. How man, so ingenious in what affects him, should have remained blind to the process of which he is a part, seems glaringly absurd. One had almost deemed the thought intuitive, did man not insist on testifying to the reverse. Darwin’s contemporaries refused even to consider his conception, demanding proof he had not to give, deaf to the self-conviction of common sense. Theirs was the cautious logic of the Irishman who, when arraigned on a charge of theft, and asked if he pleaded guilty, said, “ Faith, and how can I tell until I’ve heard the ividence.” Logic is good, but the analogic at times does better. For there is nothing but what, by slow gradation, is turning into something else. The very world he lives in changes while he is there, and the earth he waked to as a boy, by middle age has already passed away.

His very opportunity for noting was cause why he failed to see. What is oft repeated ceases to impress. Familiarity dulls perception, and leads us to accept as matters of course the daily miracle of the course of matter. His unique position as the highest product of that evolution up to date abetted his blindness. He was too self-centred to look around. The egotistic interest that nature gave him to further and perpetuate his kind grew by what it fed on, till in its overweening vanity it shut out all beyond. From the moment he began to think, we find him fashioning the universe about himself as core. His very fears and weaknesses receive anthropomorphic treatment at his hands, and hover round him to injure if not propitiated or cajoled. All else he finds designed to minister to his wants. The spot he stands on must be the pivot about which the very cosmos turns. The earth, forsooth, is the centre of the universe, because to have it otherwise detracts from his importance and minifies his fame. Around it must turn the sun, and about it revolve the stars. And all because nature implanted in him the sense of his own importance that he might the more evolve. Puppet of her contrivance, he has outdone her most sanguine hopes by taking seriously the flattery she meant for spur. The humoring of nature has its innate humor too.

Out of this plane of myopic mediocrity rises now and then a man. A mutation, the biologist would call him, a sport. And the world’s sport he usually is, or worse. The fact that he differs from his fellows is cause for condemnation at once. All animals show the like aversion to what is not their kind. It is a well-known biologic law. The sole difference in the case of man is that mental variations are most hated by humanity, bodily ones by brutes. Only intrinsic excellence enables such mutations to survive; the fact that they can stand alone in self-sufficiency.

Now the chief distinction between this man and his mates is one so evident as at first to elude full recognition. For it is simply that he is intrinsically distinct. Not so much that his intellect is keener, nor that his energy is great, though both these are ancillary to the result, but that he sees things untrammeled by the prejudices of his time. He rises superior to the crystallized conceptions of the race. This may seem a trifling matter ; in truth it involves all. If we scan history we shall find that every age has had its dogmas in every branch of life, dogmas which have completely swayed the thought of its day. It is part and parcel of man’s constitution that this should be so. Without the balance-wheel of retarding conservatism, the human machine would run awry. Nor were such ideas blamable at the time they first took start. But not one of them but had become a debased fetish at the time of its greatest cult. Like coins that have long passed current, the face they stood for has all been worn away, though their face-value remains the same. The world that uses them as counters is a different world from that which gave them vogue.

The quality of a genius consists in the ability to put off these shackles on reason and see things as they are. Bowing neither to custom nor authority, he perceives facts undistorted by the glasses society has self-imposed. Perspective orders thus the view; and imagination synthesizes the survey to inevitable conflict with his time. Lamarck saw thus, and Darwin, too; and both in their day were the abjured, not only of the ignorant, but of that lower class of scientists who conceive science to be limited to the accumulation of facts. The fact-gatherer is a necessary factor in all advance, but for him to usurp its captaincy is like the labor-champion who claimed that labor built the railroads because it laid the rails. “ Did you ever think,” said the man he addressed, “ that the end attained depended on where the rails were laid ? ”

By rising above the conventionalities and prejudices of his time, the genius attacks the problem with an open mind and gives his own fertility free scope. Had the old Greeks not been ingrained with the notion that the circle was the only perfect figure, and thus the only one that heavenly bodies could pursue, they might themselves have discovered the elliptic character of the planet’s paths. Kepler, by discarding the dogma, lit upon the law. So Darwin upset all tradition by looking it in the face. The eventual effect of such envisaging is twofold : direct, upon those capable of comprehending it ; indirect, in altering the mental attitude of mankind at large. And the second is the more potent of the two. The chief function of genius is to change the world’s point of view.

The point of view has more to do with comprehension than any amount of proof. We remember how Voltaire exposed the social fallacies of his time by introducing to their notice an unconventionalized soul, Candide, and narrating what befell him under the simple guidance of rationality and truth. How ill reason fared by the process, though every one professed to be governed by it, is there set forth. We all now see with Voltaire and are amused at the self-deception of two centuries ago. Yet the mass of us are just as blind when it comes to matters of to-day; the objects have changed, the subject remains as before.¹

The fact is, we believe we act from reason when reasoning shows we acted from belief. What we were taught in our earliest years is very hard to unlearn afterwards. And this is not only natural, but the expression of a fundamental cosmic law. One quality of matter is what is called its inertia. Inertia means a body’s objection to change of state; if the body was at rest, at rest it stays if unimpressed; if moving, it continues to move in the same direction and with like speed. It would go on forever in the same way, were no other force or friction to stop it. Now, ideas are just as subject to this basic principle as a cannon-ball. They require force to start them, but once started their momentum is immense. They go rolling down the ages long after the force that impelled them has been forgotten, so long since it was spent.

Each century starts with the ideas it was bequeathed. To alter them is no easy task. For whether right or wrong their own inertia carries them on. Even the sun could not stop the earth in a moment. A new idea means the introduction of a new force. Now, no finite force can produce its full effect at once Time is necessary for it to tell, even were it to act unhindered. But it is rarely suffered to do anything of the sort. The ideas already in the field oppose it to the utmost of their power, with the dogged persistency of the popular precept: “ Don’t push, just shove.” No wonder the newcomer finds it hard. When at last such a one has made its way we say, How simple! forgetting that the half of genius is the ability to see clearly where others are preconceivably blind, the other half the force to set its concept going. The more fundamental the idea, the more it runs counter to current belief, and the harder for it to make headway.

Neither strength nor courage is needed to profess what every one admits; to progress needs both, opposed as it is, not only by the ignorant, but by the organized scientific orthodoxy of its time. For scientists, like other men, are prone to forget that the unaccepted of to-day is the established of to-morrow, and in their attitude toward new concepts remind one of the bashful young man who was afraid to propose. At last his father twitted him with his timidity. “ That I should have a son who dared not come to the point. Where would you have been, I should like to know, had I not proposed to your mother ?” “ Oh, that is quite different,” the son replied; “ you only asked mother. I have got to ask a strange girl.” Our scientific heirlooms are our mothers; our own additions to science, the girl we have got to win. Every mother was a stranger once — and the less near of kin, the fresher blood she brought.

Especially is this the case where the new idea affects man’s vanity by lessening his self-esteem. Darwin’s ideas did both, and many of us can remember the storm of opposition they evoked. Not very creditable, as we look back upon it, to man’s intelligence, but understandable when we consider the underlying principle of inertia of mind. Perhaps no event ever brought it out more saliently, crowded with such cases as history is. For common sense, rather than uncommon subtlety, was here concerned. Proof, properly speaking, there was not. Yet the subversion was complete. Hardly a man of his own generation accepted his ideas; not a man of the next but subscribed.

But there is, unfortunately, a sad side to it which we shall do well to let sink into our hearts. A genius speaks to one world, only to be heard by another. The world of his own day turns a deaf ear to him, the world of the generation that comes after acclaims. The cause is none the less pitiful for being tautologic. Were he not ahead of his time he were no prophet. For a man to get the world’s ear while he is yet alive is his damning with faint praise. To be easily appreciated argues one too much a creature of the moment to outlast it long. Vox posteritatis vox veritatis.

But think what this means to the man himself. Any one who has ever stood at night on some isolated mountain-top, held up unshielded to the stars, knows the awe-enshrouded solitude that strikes into his soul. Under his feet is naked rock, foothold and no more; about him scanty air that yields the merest pittances of breath; above, seemingly so close at hand, the silent void where shine the frosty stars amid the outer cold of space. Everything around him stands eternally inert. No sign of life, or even hint that such a thing can be, extends so much as mute companionship. Absent are the very fringes of his own existence deemed solitude below: the trees, the grass, the flowers. Only the great elemental forces exist for him, with which he has no kin, forces working out their alien ends with an indifference that kills. To oppose them all he has but his own unconquerable will.

To be a pioneer in thought is to stand thus alone with nature, not for a few minutes, but for life. The isolateness of the few great minds of each generation of men is utterly undreamed of, for want of understanding, by those about them. Yet think what it is to pass one’s days in a thought-world where the thinker roams alone; to grapple with problems the very terms of which are beyond ordinary comprehension, and the solution appreciated only in years to come; to contemplate in lonely ecstasy, after still lonelier despair, the revelation that comes with months and more of pondering. When some one asked Newton how he came to make his wonderful discoveries, he replied, “ Simply by always thinking about them,” Consider Kepler toiling year after year fruitlessly for some ratio that should link the planet’s motions by a general law, calculating assiduously and putting hypothesis after hypothesis aside as he found it would not work, until at last, after almost inconceivable toil, he hit upon the one that would.

As if this loneliness by nature were not enough, it must needs be accentuated by man. For he rises in such cases in chorus to condemn. Consider Darwin, in patient study, testing the working out of natural selection and adding fact to fact, only to have the whole denounced as ridiculously absurd. Think you the denunciations of the master while living are wholly compensated by the plaudits after he is dead ? The loneliness of greatness is the price men make the genius pay for posthumous renown.

To him we may never make amends. But we may vicariously atone for past stupidity by timely care not to commit the like ourselves. The truest tribute to the dead is not to praise him, but to practice the principle for which his life was great. Let us, then, free ourselves as much as may be from those blinding prejudices by which each generation seeks to better its successor. Let us be open-minded, and remember that the true regard is not to accept to-day what yesterday failed to appreciate, but to champion the advance that now is making while yet it is to-day.

1. Even as this essay stood between pen and print a geologist out West, in a long letter to Science, has repeated, in reference to the facts here set forth, the old attacks on Darwin for daring to synthesize the facts ; though the geologic facts are from Sir Archibald Geikie, our own Dana, and DeLapparent, who should certainly geologically be treated with respect. Astronomically he is unaware that what prompted his contention, the Planetesimal Hypothesis, is mathematically unsound.↩