Part 11

Sir,--One of your correspondents has pithily observed, that if he has denounced Darwinism, it is simply because he believes it to be untrue. Could you not, Sir, in the interests of science and Christian charity, prevail upon him to recall his denunciation, by showing him that intellectual error requires not to be denounced, but to be set right? The prejudice against Darwinism has undoubtedly arisen from a conflict--real or apparent--between its conclusions and certain passages of Scripture. Such a prejudice arose against the earlier advancement of astronomy and geology, and the new conclusions arrived at were ‘denounced in the interests of Christian orthodoxy,’ _simply because those who denounced them believed them to be untrue._ It is a little sad, though withal a little amusing, to observe how many persons, eminent at once for piety and Protestantism, inveigh against the Papal assumption of infallibility, while assuming an infallibility of their own. They know precisely what is Scripture doctrine and what is not. They know exactly what measure of inspiration God has been pleased to give to this writer or the other. At one time they are sure that a science is not true, because the Bible does not speak in accordance with the language of the science; at another time they discover that the science had all along been very clearly revealed in the Bible under a disguise. It unfortunately escapes their notice that by this means, while they are reverently denouncing the science ‘in the interests of Christian orthodoxy,’ they are under a disguise denouncing the Bible.

‘In my view,’ says your correspondent above referred to, ‘the Mosaic writers were divinely taught, and knew what they wrote about with a most perfect knowledge.’ In one sense, no doubt, they _did_ know what they were writing about--they knew that it was religion, and, therefore, they never pretended to ‘enunciate’ science, whether false or true; but in any other sense to say that they knew what they wrote about with a most perfect knowledge, is to assert what is highly improbable, and cannot be proved. Either it makes every writer a kind of god, so far as the attribute of infallibility is concerned, or it destroys all independence of testimony. To claim for them a perfect knowledge of which they made no use, except to mislead the world for thousands of years, is surely to commit the capital offence of ‘inciting to hatred and contempt’ of their writings. How alien, moreover, is it to the spirit of the writers themselves--men who are constantly confessing their own errors, doubts, and perplexities; men whose path in moral, let alone intellectual excellence, was not always direct and straightforward, and who knew and owned their infirmity of nature. How contrary, too, to every analogy of life is this notion of a Book, written in perfect language by men of perfect knowledge in every subject that may be even incidentally referred to in its pages. For not only is man an imperfect being, but his language is an imperfect instrument of his imperfect thoughts. His conscience is fallible; his understanding is fallible; let the Book which guides him be as infallible as you please, he will still bring it back to the inherent imperfection of things human by misreading and misconceiving it. That the law of God is perfect, follows from the very thought of God; that any particular exposition of that law to finite minds either is or can be perfect, is almost, or altogether, a contradiction in terms. Far from knowing all about modern systems of Botany, Moses did not even know all about religion as the later prophets knew; nor did _they_ know as we know. Their mission would probably have been hidden rather than forwarded, had they been able to ‘enunciate’ scientific truths in advance of their age. Their new views in religion were often roundly abused; their new views in science would hardly have escaped denouncing.

As a caution to the unwary, it should be remarked that the opposition supposed to exist between Mr. Darwin’s phrase ‘Natural Selection,’ and Mr. Herbert Spencer’s ‘Survival of the Fittest,’ is purely imaginary. The latter, no doubt, is the more philosophically accurate, the former is a convenient, popular, and telling metaphor. They both express the same conception of a large and wonderful group of facts. Perhaps it will be scarcely necessary to caution the unwary against taking for granted that ‘vestigiform structures are proofs of a typical formation;’ but if they are, they prove that in the typical formation of man a tail was included, which would be such a disgrace to the typical formation as would prevent all worthy and decorously-minded persons from believing in typical formations for a moment.

DARWINISM, AND THE FIRST VERTEBRATE.

Sir,--Your amiable and earnest correspondent does not seem to understand that men like Darwin and Wallace, who have spent years of patient labour and thought in amassing observations of nature, and grouping together the facts out of which their theories have been formed, have a right to ‘an air of philosophical superiority,’ if they choose to display it, when questions are asked or arguments put forward which imply ignorance or misconception of all they have been doing in the interests of science. When Mr. Wallace ‘very coolly’ asserts that he sees no force in an argument, it will as a rule be advisable for the argument either to withdraw itself from the public gaze, or get itself stated a little more lucidly. Again, when Mr. Darwin ‘rashly affirms that he has distinct evidence’ of a thing, it would perhaps be a good plan to get the Commissioners in Lunacy to examine the astonishing number of hard-headed men whom he induces to believe his unfounded assertion.

But now that I have prevailed with your correspondent to give up ‘denouncing’ Darwinism, I wish further to press upon him the advantage of ceasing to ‘deny’ it, and, above all, of ceasing to deny it with any admixture of religious phraseology in his denial. He has himself allowed that sciences, seemingly most at variance with the language of Scripture, have come to be reconciled with it; he must see, therefore, that the appearances of Scriptural language can be no objection to Darwinism or to any other scientific theory whatever. Darwinism is founded on the comparison of an enormous number of well-ascertained facts issuing in a few generalizations of extreme importance if true, but also of considerable importance, even if far short of the truth. Every hypothesis which will explain a large number of hitherto disconnected facts, though it may be in itself erroneous, helps and guides men in the end towards the true explanation. To ‘deny,’ or, in other words, to make a public protest against such hypotheses without having anything better or equal, or a tenth part as good to offer in their stead, is to be a hinderer of science, and, instead of being really pious and reverent, is a very pretty, though doubtless unconscious imitation of that rhetoric which, because of the acknowledged difficulties in every form of religion, ‘denies’ religion altogether.

That your correspondent _does_ lay just a little tiny claim to infallibility is clear from the very letter in which he modestly disowns it: for he therein prays always to be enabled to think and act about the interpretation of Scripture as he now thinks and acts, which would be a foolish prayer, if his present thoughts and actions might possibly be wrong or misguided. And yet he differs from a very large number of divines, in supposing that the prophets, for instance, knew all that their own prophecies portended; so that if all those worthy divines be right in assuming that the inspired writers did not always ‘know what they wrote about,’ then your correspondent, who makes the contrary supposition, must be wrong,--and there will still be some hope for Darwinism.

It is scarcely fair to ask for space to answer his momentous challenge about the first vertebrate, or to explain the thoroughly sceptical form which the challenge assumes. When the Apostle Thomas said, ‘except I see the print of the nails, I will not believe,’ he had no logical claim to receive the proof of the resurrection which he demanded, because _a priori_ it would have been quite fair to suppose our Lord’s resurrection-body would retain no such signs of previous outrage; and it is a kindred mistake to suppose that the truth of the development-theory in any way hinges upon the possibility of constructing an effigy of the first vertebrate either as it actually was, or to suit an anti-Darwinian’s notions of what it ought to have been. According to the development-theory, it must have been the product of innumerable antecedent factors, itself the heir of many far-descended and often modified characters; and yet, for all that, it will probably have been a far simpler organism than the simplest modern vertebrate. It is well known by what insensible gradations the natural kingdoms and the classes in those great divisions pass, so to speak, into one another; it need, therefore, cause no surprise if the primary vertebrate of all the vertebrates should prove neither to have been fish, flesh, fowl, nor good red herring; but for an actual specimen of a living vertebrate that can neither ‘swim, crawl, fly, nor walk,’ I cannot do better than refer my philosophical opponent to a new-born baby.

THE FIRST VERTEBRATE, AND THE BEGINNING OF REASON.

Sir,--Against your correspondent’s preference for vernacular terms may be set a remark by Dr. Whewell, that ‘the loose and _infantine_ grasp of common language cannot hold objects steadily enough for scientific examination, or lift them from one stage of generalization to another. They must be secured by the rigid mechanism of a scientific phraseology.’ To say that ‘the first vertebrate must have been the product of innumerable antecedent factors,’ is, perhaps, an expression more puzzling than if one merely said that ‘its immediate progenitors’ were ‘a single pair;’ but then it has the advantage of being considerably more suggestive, and a good deal more to the purpose. Among these ‘factors’ of a living creature parents commonly find a place,--two parents generally; in some cases, only one; in some cases, not even one, if we are to believe the advocates of spontaneous generation, or the still popular view in regard to the Creation. To the parental factors of any particular offspring must be added those which are constituted by food and climate and a multitude of changes and chances in the whole course of its existence. Some characters it may derive from remote ancestors, transmitted through, though not developed in, its ‘immediate progenitors.’ It is now forty years since two French anatomists showed the possibility, or even probability, of a connection between the molluscous cuttle-fish and the vertebrate type; and, considering the propensity of the highest vertebrate for perpetually squirting ink at those who meddle with it, most readers of controversy will think the instance well selected. Those who wish to be told what the first vertebrate was probably like, should first accurately define what they mean by a vertebrate. Is a jointed backbone the only essential? And if so, how many vertebræ are essentially requisite? A creature with two vertebræ would be as much a vertebrate as a creature with three. What shall we say, then, of a creature possessing, if we may use the expression, but a single vertebra? It would not have a jointed backbone. It would not be a vertebrate. Yet, by the simple multiplication of similar parts, in accordance with a thousand analogies, a vertebrate could be developed from it. By the differentiation of these similar parts, which not only might follow, but must follow, a great variety of species could easily be evolved. Those who really take an interest in the problems connected with this subject, and whose ‘convictions’ are not too strong and absolute to be swayed by ascertained facts and logical reasoning will do well to study the ‘Principles of Biology,’ Herbert Spencer. They will there see by what extraordinarily simple gradations the lowliest organisms are connected with higher and the highest forms. They will there find that ‘modification of characters’ is a doctrine less intricate than might be supposed, even if it cannot be wholly explained in words of one syllable.

If any intelligent persons can discern the undulatory theory of light and the modern system of botany in the first chapter of Genesis, no one would wish to complain of their ingenuity, unless they proposed to support a particular theory of inspiration by these discoveries. But then, if the theories of science are only ‘the undulations of human opinion,’ it becomes necessary to ask why the botanical undulation of the present day is accepted as a witness, and the Darwinian undulation rejected. Had the famous Pagan critic, to whom your correspondent ‘R. T. E.’ refers, imagined the sentence, ‘Let there be light, and there was light,’ to be a scientific description instead of a theological one, we may feel sure that he would have condemned it for bombast instead of praising it for its majesty of expression. As it is, he does not declare it to be the sublimest sentence ever uttered, but remarks that ‘the lawgiver of the Jews, no common man, having comprehended the power of the divinity according to the just conception of it, unfolded it agreeably thereto,’ both in this and in the parallel phrase, ‘Let the dry land appear, and it was so.’ That all things which _are_ and which _become_, both are what they are and become what they become by the simple fiat of the supreme God, is a piece of elementary philosophy and religion, which, I conceive, Sir, none of your correspondents can have any wish to dispute; but that the writer of Genesis anticipated by his scientific knowledge the epoch of Copernicus and Newton, Young and Fresnel, Linnæus, De Jussieu and Cuvier, is not only not proven by the few simple phrases of his writings that have anything remotely to do with the branches of science which they so nobly illustrated; much more than this, it would be a disgrace and heavy imputation upon him had he known all _they_ believed, and yet expressed himself so badly as to leave the world for thousands of years in ignorance of the very germs of the true theories, so obscurely that no one should ever have dreamed that he was alluding to the true theories till after they had been independently discovered.

Your correspondent ‘Xn’ will find both his pleasure and his profit in reading the chapter on Instinct in ‘Darwin’s Origin of Species.’ It will give him some idea, I say not, how the reasoning faculty was first acquired, but how it may have been gradually developed. By a careful study of the same work he, and many others who need the knowledge, will see that in accordance with Darwinism the deterioration of a species is quite possible. His quaintly expressed argument about Adam’s ‘immediate progenitor’ omits to notice that in the moral world it is a step upward to become capable of sinning, just as in the physical world it is a step upward to become capable of dying, so that the wretchedest man with reason is higher in the scale than the noblest dog, and the humblest plant than the costliest and most beautiful stone. The other difficulty which he puts forward of an abrupt transition between the first man with reason and the parents of such a man without reason is a difficulty, like that in regard to the first vertebrate, one of words rather than of facts. As with the origin of language and of languages, as with the origin of the natural kingdoms and of every individual form of life, so with the origin of reason; could we see the whole series of steps, with their infinitely numerous and sometimes almost infinitely fine and subtle points of discrimination, we should probably be unable to fix upon any one definite division and say, here noise ends and articulate language begins; or, here Saxon ends and English begins; or, _this_ is the top of instinct, and _this_ the dawn of reason.

OYSTERS OF THE CHALK, AND THE THEORY OF DEVELOPMENT.[65]

The interesting notice in your last number, of M. Coquand’s ‘Oysters of the Chalk,’ draws inferences unfavourable to the theory of development or evolution which scarcely seem warranted by the facts. It need not be ‘difficult to imagine the creature as existing under such conditions, that one species, while engaged in “the struggle for existence,” should starve out and extinguish another;’ for however widely we may find a fossil species dispersed, it is not probable that it occupied the whole of its territory at one and the same time, and in the limited area occupied immediately before its extinction, new varieties may have prevailed over and displaced the old by some slightly superior adaptation to the food-supply of the region. The extinction of any particular species may in some instances have been due to the extinction, or loss by other means, of its own appropriate food. Again, it is not necessary to suppose that the hinge, or the internal or external structure of the shell of an oyster, has been altered by what may be called the direct action of ‘natural selection,’ since by the well-established principle of ‘correlation’ the variation in one part of an organism is nearly or quite certain to produce variations in other parts. ‘If any such change did occur,’ it is argued, ‘it must have been _per saltum_, since with these mollusks, numerous as they are, there are no forms that can fairly be recognised as transitional.’ But this appeal to the evidence of facts is somewhat premature. The immense difference pointed out between the geological records of England and France in regard to these very oysters of the chalk, leaves it perfectly open for us to suppose that even the comparatively full French record is itself exceedingly imperfect, and that the transitional forms have either not been preserved, or remain yet to be discovered. Mr. Darwin gives reasons for believing that when variation once begins it continues with some vigour; hence, between two settled wide-spread species connected genealogically together we might expect a large number of transitional varieties, each represented by only a few individuals, so that the whole number of these transitional forms might well be lost to the genealogical record.

Finally, the objection from the scarcity of oysters at the present day, compared with the great abundance of species in the past, does not really touch the theory of development, which is concerned to explain how species come into existence, not how they go out of it. That varieties, species, genera, have been superseded or extinguished, within longer or shorter periods, is a fact admitted on all hands. The general principle of natural selection will account for this in the rough, maintaining as it does that fresh varieties, species, and genera better adapted to the surrounding circumstances have arisen, and by their superior adaptation unavoidably ousted the older forms. Digging down into the records of history we find a time when the Romans were supreme in the civilized world; no two consecutive years of the interval present any remarkable divergence of the prevailing conditions, yet now we may say of that Roman supremacy in the civilized world, that, ‘like the Mastodon, it is a thing of the past.’

Torquay, May 14, 1870.

THE MATHEMATICAL TEST OF NATURAL SELECTION.[66]

The soul of many an anti-Darwinian will have been cheered by Mr. A. W. Bennett’s paper on ‘The Theory of Natural Selection from a Mathematical Point of View.’ It is, in fact, a very admirable piece of special pleading, based on a skilful assumption of premisses which, to a careless or biassed observer, might seem indisputable.

The tendency to variation is spoken of as something very mysterious, of which no adequate account has ever yet been given. Yet the very simple explanation is no bad one,--that where two parents are concerned in the production of any offspring, the product in part resembling each of the producers must of necessity also in part differ from each of them. Between the parents themselves, Mr. Herbert Spencer has shown that differences of age and external circumstances would ensure the requisite want of resemblance in the absence of any other cause.

‘The rigid test of mathematical calculation’ is then applied to the case of mimetic butterflies, with the view of showing that they could not have been produced simply according to the laws of variation, inheritance, and natural selection. In the application of this rigid test, the very first step is a perfectly gratuitous assumption, ‘that it would require, at the very lowest calculation, one thousand steps to enable the normal _Leptalis_ to put on its protective form.’ Who is to prove that fifty differences would be insufficient? An interval of a thousand years might be granted for establishing each one of these variations. Suppose even fifty thousand, instead of only fifty steps, to be necessary, it is another gratuitous assumption that ‘the smallest change in the direction of the _Ithomia_, which we can conceive on any hypothesis to be beneficial to the _Leptalis_, is at the very lowest one-fiftieth of the change required to produce perfect resemblance.’ How small a difference must decide the choice made by a donkey placed equidistant between two bundles of hay! Certainly, then, a bird on the wing, having to choose amidst myriads of butterflies, may be determined by an almost infinitesimal distinction. Further, though the whole change may be produced by an immense number of small changes, it is not necessary to suppose that all the changes will be equally small. It is merely begging the question to assume that the first change could not possibly be large enough to be of any use. And if it may be of use, the whole mathematical calculation, based on its being useless, breaks down from the beginning. Again, since the _Leptalis_ may have spent one million years in arriving at its present likeness to the present _Ithomia_, it is impossible to assert that the normal forms of the two butterflies were as wide apart at the beginning of that period as they are at present. The mimicry having once set in, might be retained by parallel variations. This, indeed, cannot fail to be the case, if the protection is to be a lasting one; for when the _Ithomia_ varies in outward appearance, unless the _Leptalis_ varies in the same direction, the resemblance will be lost. This progressive mimicry would be more valuable than an imitation in which no changes occurred, since the enemies of a mimetic species would in time become aware of a fraud which had no variations at its command, as birds are said now-a-days to pounce without hesitation upon caterpillars which very much resemble twigs[67]. Even ‘a rough imitation’ may be useful in the first instance, and yet when hostile eyes have long been exercised, and have acquired greater and greater sharpness, finally nothing less than _absolute identity_ of appearance may be thoroughly effective. Thus the perfecting of the resemblance will be no ‘mere freak of Nature,’ nor shall we be ‘landed in the dilemma that the _last_ stages are comparatively useless’ in this procedure.