Pioneers of Evolution from Thales to Huxley Part 4

In this brief summary of the att.i.tude of the Church toward science, it is not possible, and if it were so, it is not needful, to refer in detail to the contributions of the more speculative philosophers, who, although they made no discoveries, advocated those methods of research and directions of inquiry which made the discoveries possible. Among these a prominent name is that of Lord Bacon, whose system of philosophy, known as the Inductive, proceeds from the collection, examination and comparison of any group of connected facts to the relation of them to some general principle. The universal is thus explained by the particular. But the inductive method was no invention of Bacon's; wherever observation or testing of a thing preceded speculation about it, as with his greater namesake, there the Baconian system had its application. Lord Bacon, moreover, undervalued Greek science; he argued against the Copernican theory; and either knew nothing of, or ignored, Harvey's momentous discovery of the circulation of the blood. A more ill.u.s.trious name than his is that of Rene Descartes, a man who combined theory with observation; "one who," in Huxley's words, "saw that the discoveries of Galileo meant that the remotest parts of the universe were governed by mechanical laws, while those of Harvey meant that the same laws presided over the operations of that portion of the world which is nearest to us, namely, our own bodily frame." The greatness of this man, a good Catholic, whom the Jesuits charged with Atheism, has no mean tribute in his influence on an equally remarkable man, Benedict Spinoza. Spinoza reduced the Cartesian a.n.a.lysis of phenomena into G.o.d, mind and matter to one phenomenon, namely, G.o.d, of whom matter and spirit, extension and thought, are but attributes.

His short life fell within the longer span of Newton's, whose strange subjection to the theological influences of his age is seen in this immortal interpreter of the laws of the universe wasting his later years on an attempt to interpret unfulfilled prophecy. These and others, as Locke, Leibnitz, Herder, and Sch.e.l.ling, like the great Hebrew leader, had glimpses of a goodly land which they were not themselves to enter.

But, perhaps, in the roll of ill.u.s.trious men to whom prevision came, none have better claim to everlasting remembrance than Immanuel Kant.

For in his Theory of the Heavens, published in 1755, he antic.i.p.ates that hypothesis of the origin of the present universe which, a.s.sociated with the succeeding names of Laplace and Herschel, has, under corrections furnished by modern physics, common acceptance among us. Then, as shown in the following extract, Kant foresees the theory of the development of life from formless stuff to the highest types: "It is desirable to examine the great domain of organized beings by means of a methodical comparative anatomy, in order to discover whether we may not find in them something resembling a system, and that too in connection with their mode of generation, so that we may not be compelled to stop short with a mere consideration of forms as they are--which gives no insight into their generation--and need not despair of gaining a full insight into this department of Nature. The agreement of so many kinds of animals in a certain common plan of structure, which seems to be visible not only in their skeletons, but also in the arrangement of the other parts--so that a wonderfully simple typical form, by the shortening or lengthening of some parts, and by the suppression and development of others, might be able to produce an immense variety of species--gives us a ray of hope, though feeble, that here perhaps some results may be obtained, by the application of the principle of the mechanism of Nature; without which, in fact, no science can exist. This a.n.a.logy of forms (in so far as they seem to have been produced in accordance with a common prototype, notwithstanding their great variety) strengthens the supposition that they have an actual blood-relations.h.i.+p, due to derivation from a common parent; a supposition which is arrived at by observation of the graduated approximation of one cla.s.s of animals to another, beginning with the one in which the principle of purposiveness seems to be most conspicuous, namely, man, and extending down to the polyps, and from these even down to mosses and lichens, and arriving finally at raw matter, the lowest stage of Nature observable by us. From this raw matter and its forces, the whole apparatus of Nature seems to have been derived according to mechanical laws (such as those which resulted in the production of crystals); yet this apparatus, as seen in organic beings, is so incomprehensible to us, that we feel ourselves compelled to conceive for it a different principle. But it would seem that the archaeologist of Nature is at liberty to regard the great Family of creatures (for as a Family we must conceive it, if the above-mentioned continuous and connected relations.h.i.+p has a real foundation) as having sprung from their immediate results of her earliest revolutions, judging from all the laws of their mechanisms known to or conjectured by him."

In our arrival at the age of these seers, we feel the play of a freer, purer air; a lull in the miasmatic currents that bring intolerance on their wings. The tolerance that approaches is due to no surrender of its main position by dogmatic theology, but to that larger perception of the variety and complexity of life, ignorance of, or wilful blindness to, which is the secret of the survival of rigid opinion. The demonstration of the earth's roundness; the discovery of America; the growing conception of inter-relation between the lowest and the highest life-forms; the slow but sure acceptance of the Copernican theory; and, above all, the idea of a Cosmos, an unbroken order, to which every advance in knowledge contributes, justified and fostered the free play of the intellect. Foreign as yet, however, to the minds of widest breadth, was the conception of the inclusion of MAN himself in the universal order. Duality--Nature overruled by supernature--was the unaltered note; the supernature as part of Nature a thing undreamed of.

Nor could it be otherwise while the belief in diabolical agencies still held the field, sending wretched victims to the stake on the evidence of conscientious witnesses, and with the concurrence of humane judges.

Animism, the root of all personification, whether of good or evil, had lost none of its essential character, and but little of its vigour.

"I flatter myself," says Hume, in the opening words of the essay upon Miracles, in his Inquiry Concerning Human Understanding, "that I have discovered an argument of a like nature (he is referring to Archbishop Tillotson's argument on Transubstantiation) which, if just, will, with the wise and learned, be an everlasting check to all kind of superst.i.tious delusion, and, consequently, will be useful as long as the world endures." Hume certainly did not overrate the force of the blow which he dealt at supernaturalism, one of a series of attacks which, in France and Britain, carried the war into the camp of the enemy, and changed its tactics from aggressive to defensive. But none the less is it true that the "superst.i.tious delusions" against which he planted his logical artillery were killed neither by argument nor by evidence.

Delusion and error do not perish by controversial warfare. They perish under the slow and silent operation of changes to which they are unable to adapt themselves. The atmosphere is altered: the organism can neither respond nor respire; therefore, it dies. Thus, save where lurks the ignorance which is its breath of life, has wholly perished belief in witchcraft; thus, too, is slowly peris.h.i.+ng belief in miracles, and, with this, belief in the miraculous events, the incarnation, resurrection, and ascension of Jesus, on which the fundamental tenets of Christianity are based, and in which lies so largely the secret of its long hostility to knowledge.

_PART III._

THE RENASCENCE OF SCIENCE.

A. D. 1600 ONWARDS.

"Though science, like Nature, may be driven out with a fork, ecclesiastical or other, yet she surely comes back again."--HUXLEY, Prologue to Collected Essays, vol. v.

The exercise of a more tolerant spirit, to which reference has been made, had its limits. It is true that Dr. South, a famous divine, denounced the Royal Society (founded 1645) as an irreligious body; although a Dr. Wallis, one of the first members, especially declared that "matters of theology" were "precluded": the business being "to discourse and consider of philosophical inquiries and such as related thereunto; as Physick, Anatomy, Geometry, Astronomy, Navigation, Staticks, Magneticks, Chymicks, and Natural Experiments; with the state of these studies, and their cultivation at home and abroad."

Regardless of South and such as agreed with him, Torricelli worked at hydrodynamics, and discovered the principle of the barometer; Boyle inquired into the law of the compressibility of gases; Malpighi examined minute life-forms and the structure of organs under the microscope; Ray and Willughby cla.s.sified plants and animals; Newton theorized on the nature of light; and Roemer measured its speed; Halley estimated the sun's distance, predicted the return of comets, and observed the transits of Venus and Mercury; Hunter dissected specimens, and laid the foundations of the science of comparative anatomy; and many another ill.u.s.trious worker contributed to the world's stock of knowledge "without let or hindrance," for in all this "matters of theology were precluded."

But the old spirit of resistance was aroused when, after a long lapse of time, inquiry was revived in a branch of science which, it will be noticed, has no distinct place in the subjects dealt with by the Royal Society at the start. That science was Geology; a science destined, in its ultimate scope, to prove a far more powerful dissolvent of dogma than any of its compeers.

It seems strange that the discovery of the earth's true shape and movements was not sooner followed by investigation into her contents, but the old ideas of special creation remained unaffected by these and other discoveries, and the more or less detailed account of the process of creation furnished in the book of Genesis sufficed to arrest curiosity. In the various departments of the inorganic universe the earth was the last to become subject of scientific research; as in study of the organic universe, man excluded himself till science compelled his inclusion.

After more than two thousand years, the Ionian philosophers "come to their own" again. Xenophanes of Colophon has been referred to as arriving, five centuries B. C., at a true explanation of the imprints of plants and animals in rocks. Pythagoras, who lived before him, may, if Ovid, writing near the Christian era, is to be trusted, have reached some sound conclusions about the action of water in the changes of land and sea areas. But we are on surer ground when we meet the geographer Strabo, who lived in the reign of Augustus. Describing the countries in which he travelled, he notes their various features, and explains the causes of earthquakes and allied phenomena. Then eleven hundred years pa.s.s before we find any explanation of like rational character supplied.

This was furnished by the Arabian philosopher, Avicenna, whose theory of the origin of mountains is the more marvellous when we remember what intellectual darkness surrounded him. He says that "mountains may be due to two different causes. Either they are effects of upheavals of the crust of the earth, such as might occur during a violent earthquake, or they are the effect of water, which, cutting for itself a new route, has denuded the valleys, the strata being of different kinds, some soft, some hard. The winds and waters disintegrate the one, but leave the other intact. Most of the eminences of the earth have had this latter origin. It would require a long period of time for all such changes to be accomplished, during which the mountains themselves might be somewhat diminished in size. But that water has been the main cause of these effects is proved by the existence of fossil remains of aquatic and other animals on many mountains" (cf. Osborn's From the Greeks to Darwin, p. 76). A similar explanation of fossils was given by the engineer-artist Leonardo de Vinci in the fifteenth century, and by the potter Bernard Palissy, in the sixteenth century; but thence onward, for more than a hundred years, the earth was as a sealed book to man.

The earlier chapters of its history, once reopened, have never been closed again. Varied as were the theories of the causes which wrought manifold changes on its surface, they agreed in demanding a far longer time-history than the Church was willing to allow. If the reasoning of the geologists was sound, the narrative in Genesis was a myth. Hence the renewal of struggle between the Christian Church and Science, waged, at first, over the six days of the Creation.

Here and there, in bygone days, a sceptical voice had been raised in denial of the Mosaic authors.h.i.+p of the Pentateuch. Such was that of La Peyrere who, in 1655, published an instalment of a work in which he antic.i.p.ated what is nowadays accepted, but what then was akin to blasphemy to utter. For not only does he doubt whether Moses had any hand in the writings attributed to him: he rejects the orthodox view of suffering and death as the penalties of Adam's disobedience; and gives rationalistic interpretation of the appearance of the star of Bethlehem, and of the darkness at the Crucifixion. But La Peyrere became a Roman Catholic, and, of course, recanted his opinions. Then, nearer the time when controversy on the historical character of the Scriptures was becoming active, one Astruc, a French physician, suggested, in a work published in 1753, that Moses may have used older materials in his compilation of the earlier parts of the Pentateuch.

But, practically, the five books included under that name, were believed to have been written by Moses under divine authority. The statement in Genesis that G.o.d made the universe and its contents, both living and non-living, in six days of twenty-four hours each, was explicit. Thus interpreted, as their plain meaning warranted, Archbishop Usher made his famous calculation as to the time elapsing between the creation and the birth of Christ. Dr. White, in his important Warfare of Science with Theology, gives an amusing example of the application of Usher's method in detail. A seventeenth century divine, Dr. Lightfoot, Vice-Chancellor of Cambridge University, computed that "man was created by the Trinity on 23d October, 4004 B. C., at nine o'clock in the morning." The same theologian, who, by the way, was a very eminent Hebrew scholar, following the interpretation of the great Fathers of the Church, "declared, as the result of profound and exhaustive study of the Scriptures, that 'heaven and earth, centre and circ.u.mference, and clouds full of water, were created all together, in the same instant.'"

The story of the Deluge was held to furnish sufficing explanation of the organic remains yielded by the rocks, but failing this, a mult.i.tude of fantastic theories were at hand to explain the fossils. They were said to be due to a "formative quality" in the soil; to its "plastic virtue"; to a "lapidific juice"; to the "fermentation of fatty matter"; to "the influence of the heavenly bodies," or, as the late eminent naturalist, Philip Gosse, seriously suggested in his whimsical book Omphalos: an Attempt to untie the Geological Knot, they were but simulacra wherewith a mocking Deity rebuked the curiosity of man. Every explanation, save the right and obvious one, had its defenders, because it was essential to support some theory to rebut the evidence supplied by remains of animals as to the existence of death in the world before the fall of Adam. Otherwise, the statements in the Old Testament, on which the Pauline reasoning rested, were baseless, and to discredit these was to undermine the authority of the Scriptures from Genesis to the Apocalypse. No wonder, therefore, that theology was up in arms, or that it saw in geology a deadlier foe than astronomy had seemed to be in ages past. The Sorbonne, or Faculty of Theology, in Paris burnt the books of the geologists, banished their authors, and, in the case of Buffon, the famous naturalist, condemned him to retract the awful heresy, which was declared "contrary to the creed of the Church," contained in these words: "The waters of the sea have produced the mountains and valleys of the land; the waters of the heavens, reducing all to a level, will at last deliver the whole land over to the sea, and the sea successively prevailing over the land, will leave dry new continents like those which we inhabit." So the old man repeated the submission of Galileo, and published his recantation: "I declare that I had no intention to contradict the text of Scripture; that I believe most firmly all therein related about the creation, both as to order of time and matter of fact.

I abandon everything in my book respecting the formation of the earth, and generally all which may be contrary to the narrative of Moses." That was in the year 1751.

If the English theologians could not deliver heretics of the type of Buffon to the secular arm, they used all the means that denunciation supplied for delivering them over to Satan. Epithets were hurled at them; arguments drawn from a world accursed of G.o.d levelled at them.

Saint Jerome, living in the fourth century, had pointed to the cracked and crumpled rocks as proof of divine anger: now Wesley and others saw in "sin the moral cause of earthquakes, whatever their natural cause might be," since before Adam's transgression, no convulsions or eruptions ruffled the calm of Paradise. Meanwhile, the probing of the earth's crust went on; revealing, amidst all the seeming confusion of distorted and metamorphosed rocks, an unvarying sequence of strata, and of the fossils imbedded in them. Different causes were a.s.signed for the vast changes ranging over vast periods; one school believing in the action of volcanic and such like catastrophic agents; another in the action of aqueous agents, seeing, more consistently, in present operations the explanation of the causes of past changes. But there was no diversity of opinion concerning the extension of the earth's time-history and life-history to millions on millions of years.

So, when this was to be no longer resisted, theologians sought some basis of compromise on such non-fundamental points as the six days of creation. It was suggested that perhaps these did not mean the seventh part of a week, but periods, or eons, or something equally elastic; and that if the Mosaic narrative was regarded as a poetic revelation of the general succession of phenomena, beginning with the development of order out of chaos, and ending with the creation of man, Scripture would be found to have antic.i.p.ated or revealed what science confirms. It was impossible, so theologians argued, that there could be aught else than harmony between the divine works and the writings which were a.s.sumed to be of divine origin. Science could not contradict revelation, and whatever seemed contradictory was due to misapprehension either of the natural fact, or to misreading of the written word. But although the story of the creation might be clothed, as so exalted and moving a theme warranted, in poetic form, that of the fall of Adam and of the drowning of his descendants, eight persons excepted, must be taken in all its appalling literalness. Confirmation of the Deluge story was found in the fossil sh.e.l.ls on high mountain tops; while as for the giants of antediluvian times, there were the huge bones in proof. Some of these relics of mastodon and mammoth were actually hung up in churches as evidence that "there were giants in those days"! Geoffroy Saint-Hilaire tells of one Henrion, who published a book in 1718 giving the height of Adam as one hundred and twenty-three feet nine inches, and of Eve as one hundred and eighteen feet nine inches, Noah being of rather less stature. But to parley with science is fatal to theology. Moreover, arguments which involve the cause they support in ridicule may be left to refute themselves. And while theology was hesitating, as in the amusing example supplied by Dr. William Smith's Dictionary of the Bible (published in 1863) wherein the reader, turning up the article "Deluge,"

is referred to "Flood," and thence to "Noah"; archaeology produced the Chaldaean original of the legend whence the story of the flood is derived. With candour as commendable as it is rare, the Reverend Professor Driver, from whom quotation has been made already, admits that "read without prejudice or bias, the narrative of Genesis i. creates an impression at variance with the facts revealed by science"; all efforts at reconciliation being only "different modes of obliterating the characteristic features of Genesis, and of reading into it a view which it does not express."

While the ground in favour of the literal interpretation of Genesis was being contested, an invading force, that had been gathering strength with the years, was advancing in the shape of the science of Biology.

The workers therein fall into two cla.s.ses: the one, represented by Linnaeus and his school, applied themselves to the cla.s.sifying and naming of plants and animals; the other, represented by Cuvier and his school, examined into structure and function. Anatomy made clear the machinery: physiology the work which it did, and the conditions under which the work was done. Then, through comparison of corresponding organs and their functions in various life-forms, came growing perception of their unity. But only to a few came gleams of that unity as proof of common descent of plant and animal, for, save in scattered hints of inter-relation between species, which occur from the time of Lord Bacon onward, the theory of their immutability was dominant until forty years ago.

Four men form the chief vanguard of the biological movement. "Modern cla.s.sificatory method and nomenclature have largely grown out of the work of Linnaeus; the modern conception of biology, as a science, and of its relation to climatology, geography, and geology, are as largely rooted in the labours of Buffon; comparative anatomy and palaeontology owe a vast debt to Cuvier's results; while invertebrate zoology and the revival of the idea of Evolution are intimately dependent on the results of the work of Lamarck. In other words, the main results of biology up to the early years of this century are to be found in, or spring out of, the works of these men."

Linnaeus, son of a Lutheran pastor, born at Roeshult, in Sweden, in 1707, had barely pa.s.sed his twenty-fifth year before laying the ground-plan of the system of cla.s.sification which bears his name, a system which advance in knowledge has since modified. Based on external resemblances, its formulation was possible only to a mind intent on minute and accurate detail, and less observant of general principles. In brief, the work of Linnaeus was constructive, not interpretative. Hence, perhaps, conjoined to the theological ideas then current, the reason why the larger question of the fixity of species entered not into his purview. To him each plant and animal retained the impress of the Creative hand that had shaped it "in the beginning," and, throughout his working life, he departed but slightly from the plan with which he started, namely, "reckoning as many species as issued in pairs" from the Almighty fiat.

Not so Buffon, born on his father's estate in Burgundy in the same year as Linnaeus, whom he survived ten years, dying in 1788. His opinions, clas.h.i.+ng as they did with orthodox creeds, were given in a tentative, questioning fas.h.i.+on, so that where ecclesiastical censure fell, retreat was easier. As has been seen in his submission to the Sorbonne, he was not of the stuff of which martyrs are made. Perhaps he felt that the ultimate victory of his opinions was sufficiently a.s.sured to make self-sacrifice needless. But, under cover of pretence at inquiry, his convictions are clear enough. He was no believer in the permanent stability of species, and noted, as warrant of this, the otherwise unexplained presence of aborted or rudimentary structures. For example, he says, "the pig does not appear to have been formed upon an original, special, and perfect plan, since it is a compound of other animals; it has evidently useless parts, or rather, parts of which it cannot make any use, toes, all the bones of which are perfectly formed, and which, nevertheless, are of no service to it. Nature is far from subjecting herself to final causes in the formation of her creatures." Then, further, as showing his convictions on the non-fixity of species, he says, how many of them, "being perfected or degenerated by the great changes in land and sea, by the favours or disfavours of Nature, by food, by the prolonged influences of climate, contrary or favourable, are no longer what they formerly were." But he writes with an eye on the Sorbonne when, hinting at a possible common ancestor of horse and a.s.s, and of ape and man, he slyly adds that since the Bible teaches the contrary, the thing cannot be. Thus he attacked covertly; by adit, not by direct a.s.sault; and to those who read between the lines there was given a key wherewith to unlock the door to the solution of many biological problems. Buffon, consequently, was the most stimulating and suggestive naturalist of the eighteenth century. There comes between him and Lamarck, both in order of time and sequence of ideas, Erasmus Darwin, the distinguished grandfather of Charles Darwin.

Born at Eton, near Newark, in 1731, he walked the hospitals at London and Edinburgh, and settled, for some years, at Lichfield, ultimately removing to Derby. Since Lucretius, no scientific writer had put his cosmogonic speculations into verse until Dr. Darwin made the heroic metre, in which stereotyped form the poetry of his time was cast, the vehicle of rhetorical descriptions of the amours of flowers and the evolution of the thumb. The Loves of the Plants, ridiculed in the Loves of the Triangles in the Anti-Jacobin, is not to be named in the same breath, for stateliness of diction, and majesty of movement, as the De rerum Natura. But both the prose work Zoonomia and the poem The Temple of Nature (published after the author's death in 1802) have claim to notice as the matured expression of conclusions at which the clear-sighted, thoughtful, and withal, eccentric doctor had arrived in the closing years of his life. Krause's Life and Study of the Works of Erasmus Darwin supplies an excellent outline of the contents of books which are now rarely taken down from the shelves, and makes clear that their author had the root of the matter in him. His observations and reading, for the influence of Buffon and others is apparent in his writings, led him to reject the current belief in the separate creation of species. He saw that this theory wholly failed to account for the existence of abnormal forms, of adaptations of the structure of organs to their work, of gradations between living things, and other features inconsistent with the doctrine of "let lions be, and there were lions."

His shrewd comment on the preformation notion of development has been quoted (p. 20). The substance of his argument in support of a "physical basis of life" is as follows: "When we revolve in our minds the metamorphosis of animals, as from the tadpole to the frog; secondly, the changes produced by artificial cultivation, as in the breeds of horses, dogs, and sheep; thirdly, the changes produced by conditions of climate and of season, as in the sheep of warm climates being covered with hair instead of wool, and the hares and partridges of northern climates becoming white in winter; when, further, we observe the changes of structure produced by habit, as seen especially by men of different occupations; or the changes produced by artificial mutilation and prenatal influences, as in the crossing of species and production of monsters; fourth, when we observe the essential unity of plan in all warm-blooded animals--we are led to conclude that they have been alike produced from a similar living filament." The concluding words of this extract make remarkable approach to the modern theory of the origin of life in the complex jelly-like protoplasm, or, as some call it, nuclein or nucleoplasm. And, on this, Erasmus Darwin further remarks: "As the earth and ocean were probably peopled with vegetable productions long before the existence of animals, and many families of these animals long before other animals of them, shall we conjecture that one and the same kind of living filament is and has been the cause of all organic life?"

Nor does he make any exception to this law of organic development. He quotes Buffon and Helvetius to the effect--"that many features in the anatomy of man point to a former quadrupedal position, and indicate that he is not yet fully adapted to the erect position; that, further, man may have arisen from a single family of monkeys, in which, accidentally, the opposing muscle brought the thumb against the tips of the fingers, and that this muscle gradually increased in size by use in successive generations." While we who live in these days of fuller knowledge of agents of variation may detect the _minus_ in all foregoing speculations, our interest is increased in the thought of their near approach to the cardinal discovery. And a rapid run through the later writings of Dr. Darwin shows that there is scarcely a side of the great theory of Evolution which has escaped his notice or suggestive comment.

Grant Allen, in his excellent little monograph on Charles Darwin, says that the theory of "natural selection was the only cardinal one in the evolutionary system on which Erasmus Darwin did not actually forestall his more famous and greater namesake. For its full perception, the discovery of Malthus had to be collated with the speculations of Buffon."

In the Historical Sketch on the Progress of Opinion on the Origin of Species, which Darwin prefixed to his book, he refers to Lamarck as "the first man whose conclusions on the subject excited much attention;"

rendering "the eminent service of arousing attention to the probability of all change in the organic, as well as in the inorganic world, being the result of law, and not of miraculous interposition." Lamarck was born at Bezantin, in Picardy, in 1744. Intended for the Church, he chose the army, but an injury resulting from a practical joke cut short his career as a soldier. He then became a banker's clerk, in which occupation he secured leisure for his favourite pursuit of natural history. Through Buffon's influence he procured a civil appointment, and ultimately became a colleague of Cuvier and Geoffroy St. Hilaire in the Museum of Natural History at Paris. Of Cuvier it will here suffice to say that he remained to the end of his life a believer in special creation, or, what amounts to the same thing, a series of special creations which, he held, followed the catastrophic annihilations of prior plants and animals. Although orthodox by conviction, his researches told against his tenets, because his important work in the reconstruction of skeletons of long extinct animals laid the foundation of palaeontology.

To Lamarck, says Haeckel, "will always belong the immortal glory of having for the first time worked out the Theory of Descent as an independent scientific theory of the first order, and as the philosophical foundation of the whole science of Biology." He taught that in the beginnings of life only the very simplest and lowest animals and plants came into existence; those of more complex structure developing from these; man himself being descended from ape-like mammals. For the Aristotelian mechanical figure of life as a ladder, with its detached steps, he subst.i.tuted the more appropriate figure of a tree, as an inter-related organism. He argued that the course of the earth's development, and also of all life upon it, was continuous, and not interrupted by violent revolutions. In this he followed Buffon and Hutton. Buffon, in his Theory of the Earth, argues that "in order to understand what had taken place in the past, or what will happen in the future, we have but to observe what is going on in the present." This is the keynote of modern geology. "Life," adds Lamarck, "is a purely physical phenomenon. All its phenomena depend on mechanical, physical, and chemical causes which are inherent in the nature of matter itself."

He believed in a form of spontaneous generation. Rejecting Buffon's theory of the direct action of the surroundings as agents of change in living things, he sums up the causes of organic evolution in the following propositions:

1. Life tends by its inherent forces to increase the volume of each living body and of all its parts up to a limit determined by its own needs.

2. New wants in animals give rise to new movements which produce organs.

3. The development of these organs is in proportion to their employment.

4. New developments are transmitted to offspring.

The second and third propositions were ill.u.s.trated by examples which have, with good reason, provoked ridicule. Lamarck accounts for the long neck of the giraffe by that organ being continually stretched out to reach the leaves at the tree-tops; for the long tongue of the ant-eater or the woodp.e.c.k.e.r by these creatures protruding it to get at food in channel or crevice; for the webbed feet of aquatic animals by the outstretching of the membranes between the toes in swimming; and for the erect position of man by the constant efforts of his ape-like ancestors to keep upright. The legless condition of the serpent which, in the legend of the Garden of Eden, is accounted for on moral grounds, is thus explained by Lamarck: "Snakes sprang from reptiles with four extremities, but having taken up the habit of moving along the earth and concealing themselves among bushes, their bodies, owing to repeated efforts to elongate themselves and to pa.s.s through narrow s.p.a.ces, have acquired a considerable length out of all proportion to their width.

Since long feet would have been very useless, and short feet would have been incapable of moving their bodies, there resulted a cessation of use of these parts, which has finally caused them to totally disappear, although they were originally part of the plan of organization in these animals." The discovery of an efficient cause of modifications, which Lamarck refers to the efforts of the creatures themselves, has placed his speculations in the museum of biological curiosities; but sharp controversy rages to-day over the question raised in Lamarck's fourth proposition, namely, the transmission of characters acquired by the parent during its lifetime to the offspring. This burning question between Weismann and his opponents, involving the serious problem of heredity, will remain unsettled till a long series of observations supply material for judgment.

Lamarck, poor, neglected, and blind in his old age, died in 1829. Both Cuvier, who ridiculed him, and Goethe, who never heard of him, pa.s.sed away three years later. The year following his death, when Darwin was an undergraduate at Cambridge, Lyell published his Principles of Geology, a work destined to a.s.sist in paving the way for the removal of one difficulty attending the solution of the theory of the origin of species, namely, the vast period of time for the life-history of the globe which that theory demands. As Lyell, however, was then a believer--although, like a few others of his time, of wavering type--in the fixity of species, he had other aims in view than those to which his book contributed. But he wrote with an open mind, not being, as Herbert Spencer says of Hugh Miller, "a theologian studying geology." Following the theories of uniformity of action laid down by Hutton, by Buffon, and by that industrious surveyor, William Smith, who travelled the length and breadth of England, mapping out the sequence of the rocks, and tabulating the fossils special to each stratum, Lyell demonstrated in detail that the formation and features of the earth's crust are explained by the operation of causes still active. He was one among others, each working independently at different branches of research; each, unwittingly, collecting evidence which would help to demolish old ideas, and support new theories.

A year after the Principles of Geology appeared, there crept unnoticed into the world a treatise, by one Patrick Matthew, on Naval Timber and Arboriculture, under which unexciting t.i.tle Darwin's theory was antic.i.p.ated. Of this, however, as of a still earlier antic.i.p.ation, more presently. About this period Von Baer, in examining the embryos of animals, showed that creatures so unlike one another in their adult state as fishes, lizards, lions, and men, resemble one another so closely in the earlier stages of their development that no differences can be detected between them. But Von Baer was himself antic.i.p.ated by Meckel, who wrote as follows in 1811: "There is no good physiologist who has not been struck, incidentally, by the observation that the original form of all organisms is one and the same, and that out of this one form, all, the lowest as well as the highest, are developed in such a manner that the latter pa.s.s through the permanent forms of the former as transitory stages" (Osborn's From the Greeks to Darwin, p. 212). In botany Conrad Sprengel, who belongs to the eighteenth century, had shown the work effected by insects in the fertilization of plants. Following his researches, Robert Brown made clear the mode of the development of plants, and Sir William Hooker traced their habits and geographical distribution. Von Mohl discovered that material basis of both plant and animal which he named "protoplasm." In 1844, nine years before Von Mohl told the story of the building-up of life from a seemingly structureless jelly, a book appeared which critics of the time charged with "poisoning the fountains of science, and sapping the foundations of religion." This was the once famous Vestiges of Creation, acknowledged after his death as the work of Robert Chambers, in which the origin and movements of the solar system were explained as determined by uniform laws, themselves the expression of Divine power. Organisms, "from the simplest and oldest, up to the highest and most recent," were the result of an "inherent impulse imparted by the Almighty both to advance them from the several grades and modify their structure as circ.u.mstances required."

Although now referred to only as "marking time" in the history of the theory of Evolution, the book created a sensation which died away only some years after its publication. Darwin remarks upon it in his Historical Sketch that although displaying "in the earlier editions little accurate knowledge and a great want of scientific knowledge, it did excellent service in this country in calling attention to the subject, in removing prejudice, and in thus preparing the ground for the reception of a.n.a.logous views."

Three years after the Vestiges, there was, although none then knew it, or knowing the fact, would have admitted it, more "sapping of the foundations" of orthodox belief, when M. Boucher de Perthes exhibited some rudely-shaped flint implements which had been found at intervals in hitherto undisturbed deposits of sand and gravel--old river beds--in the Somme valley, near Abbeville, in Picardy. For these rough stone tools and weapons, being of human workmans.h.i.+p, evidenced the existence of savage races of men in Europe in a dim and dateless past, and went far to refute the theories of his paradisiacal state on that memorable "23 October, 4004 B. C.," when, according to Dr. Lightfoot's reckoning (see p. 103), Adam was created. While the pickaxe, in disturbing flint knives and spearheads, that had lain for countless ages, was disturbing much besides, English and German philosophers were formulating the imposing theory which, under the name of the Conservation of Energy, makes clear the indestructibility of both matter and motion. Then, to complete the work of preparation effected by the discoveries now briefly outlined, there appeared, in a now defunct newspaper, the Leader, in its issue of 20th of March, 1852, an article by Herbert Spencer on the Development Hypothesis, in which the following striking pa.s.sage occurs: "Those who cavalierly reject the Theory of Evolution, as not adequately supported by facts, seem quite to forget that their own theory is supported by no facts at all. Like the majority of men who are born to a given belief, they demand the most rigorous proof of any adverse belief, but a.s.sume that their own needs none. Here we find, scattered over the globe, vegetable and animal organisms numbering, of the one kind (according to Humboldt) some 320,000 species, and of the other, some 2,000,000 species (see Carpenter); and if to these we add the numbers of animal and vegetable species that have become extinct, we may safely estimate the number of species that have existed, and are existing, on the earth, at not less than _ten millions_. Well, which is the most rational theory about these ten millions of species? Is it most likely that there have been ten millions of special creations? or is it most likely that by continual modifications, due to change of circ.u.mstances, ten millions of varieties have been produced, as varieties are being produced still?...

Even could the supporters of the Development Hypothesis merely show that the origination of species by the process of modification is conceivable, they would be in a better position than their opponents.

But they can do much more than this. They can show that the process of modification has effected, and is effecting, decided changes in all organisms subject to modifying influences.... They can show that in successive generations these changes continue, until ultimately the new conditions become the natural ones. They can show that in cultivated plants, domesticated animals, and in the several races of men, such alterations have taken place. They can show that the degrees of difference so produced are often, as in dogs, greater than those on which distinctions of species are in other cases founded. They can show, too, that the changes daily taking place in ourselves--the facility that attends long practice, and the loss of apt.i.tude that begins when practice ceases--the strengthening of pa.s.sions habitually gratified, and the weakening of those habitually curbed--the development of every faculty, bodily, moral, or intellectual, according to the use made of it--are all explicable on this same principle. And thus they can show that throughout all organic nature there is at work a modifying influence of the kind they a.s.sign as the cause of these specific differences; an influence which, though slow in its action, does, in time, if the circ.u.mstances demand it, produce marked changes--an influence which, to all appearance, would produce in the millions of years, and under the great varieties of condition which geological records imply, any amount of change."

This quotation shows, as perhaps no other reference might show, how, by the middle of the present century, science was trembling on the verge of discovery of that "modifying influence" of which Mr. Spencer speaks.

That discovery made clear how all that had preceded it not only contributed thereto, but gained a significance and value which, apart from it, could not have been secured. When the relation of the several parts to the whole became manifest, each fell into its place like the pieces of a child's puzzle map.

LEADING MEN OF SCIENCE.

A. D. 800 TO A. D. 1800.

--------------------+-----------------+------+------------------------ Place and date NAME. of birth. Died. Speciality.

--------------------+-----------------+------+------------------------ Geber (Djafer). Mesopotamia, .... Earliest known Chemist.

830. Avicenna (Ibu Sina). Bokhara, 980. 1037 Expositor of Aristotle; Physician and Geologist.

Averroes (Ibu Spain, 1126. 1198 Translator and Roshd). Commentator of Aristotle.