페이지 이미지
[merged small][graphic]
[graphic][merged small][ocr errors][merged small]

In Mr. Darwin's last work we possess at length a complete and thorough exposition of his matured views. He gives us the results of the patient labor of many years unremitting investigation and of the application of a powerful and acute intellect, combined with an extraordinarily active imagination, to an unequalled collection of most varied, interesting and important biological data. In his earlier writings a certain reticence veiled, though it did not hide, his ultimate conclusions as to the origin of our own species; but now all possibility of misunderstanding or of a repetition of former disclaimers on the part of any disciple is at an end, and the entire and naked truth as to the logical consequences of Darwinism is displayed with a frankness which we had a right to expect from the distinguished author. What was but obscurely hinted in the

Tht Descent of Man, and Selection in Relation to Sex. By Charles Darwin, M.A., F.R.S., &c. 2 vols. London and New York: 1871.

New SeriesVol. XIV., No. 4.

"Origin of Species" is here fully and fairly stated in all its bearings and without disguise. Mr. Darwin has, in fact, " crowned the edifice," and the long looked for and anxiously awaited detailed statement of his views as to the human race is now unreservedly put before us.

We rise from the careful pemsal of this book with mingled feelings of admiration and disappointment. The author's style is clear and attractive—clearer than in his earlier works—and his desire to avoid every kind of conscious misrepresentation is as conspicuous as ever. The number of interesting facts brought forward is as surprising as is the ingenuity often displayed in his manipulation of them. Under these circumstances it is a most painful task to have to point out grave defects and serious short-comings. Mr. Darwin, however, seems in his recent work even more than in his earlier productions to challenge criticism and to have thrown out ideas and suggestions with a distinct view to their subsequent modification by others. It is but


an act'of fairness to call attention to this :—

"False facts," says Mr. Darwin, "are highly injurious to the progress of science, for they often long endure; but false views, if supported by some evidence, do little harm, as every one takes a salutary pleasure in proving their falseness; and when this is done, one path towards error is closed and the road to truth is often at the same time opened."—Descent of Man, vol. ii. p. 38S.

Although we are unable to agree entirely with Mr. Darwin in this remark, it none the less contains an undoubted truth. We cannot agree, because we feel that a false theory which keenly solicits the imagination, put forward by a writer widely and deservedly esteemed, and which reposes on a multitude of facts difficult to verify, skilfully interwoven, and exceedingly hard to unravel, is likely to be very prejudicial to science. Nevertheless, science cannot make progress without the action of two distinct classes of thinkers : the first consisting of men of creative genius, who strike out brilliant hypotheses, and who may be spoken of as "theorizers" in the good sense of the word; the second, of men possessed of the critical faculty, and who test, mould into shape, perfect or destroy, the hypotheses thrown out by the former class.

Obviously important as it is that there should be such theorizers, it is also most important that criticism should clearly point out when a theory is really proved, when it is but probable, and when it is a mere arbitrary hypothesis. This is all the more necessary if, as may often and very easily happen, from being repeatedly spoken of, and being connected with celebrated and influential names, it is likely to be taken for very much more than it is really worth.

The necessity of caution in respect to this is clearly shown by Mr. Darwin's present work, in which "sexual selection," from being again and again referred to as if it had proved to be a vera causa, may readily be accepted as such by the uninstructed or careless reader. For' many persons, at first violently opposed through ignorance or prejudice to Mr. Darwin's views, are now, with scarcely less ignorance and prejudice, as strongly inclined in "their favor.

Mr. Darwin's recent work, supplemen

ting and completing, as it does, his earlier publications, offers a good opportunity for reviewing his whole position. We shall thus be better able to estimate the value of his convictions regarding the special subject of his present inquiry. We shall first call attention to his earlier statements, in order that we may see whether he has modified his views, and, if so, how far and with what results. If he has, even by his own showing and admission, been overhasty and seriously mistaken previously, we must be the more careful how we commit ourselves to his guidance now. We shall endeavor to show that Mr. Darwin's convictions have undergone grave modifications, and that the opinions adopted by him now are quite distinct from, and even subversive of, the views hq originally put forth. The assignment of the law of "natural selection " to a subordinate position is virtually an abandonment of the Darwinian theory ;. for the one distinguishing feature of that theory was the all-sufficiency of "natural selection." Not the less, however, ought we to feel grateful to Mr. Darwin for bringing forward that theory, and for forcing on men's minds, by his learning, acuteness, zeal, perseverance, firmness, and candor, a recognition of the probability, if not more, of evolution and of the certainty of the action of "natural selection." For though the "survival of the fittest" is a truth which readily presents itself to any one who considers the subject, and though its converse, the destruction of the least fit, was recognized thousands of years ago, yet to Mr. Darwin, and (through Mr. Wallace's reticence) to Mr. Darwin alone, is due the credit of having first brought it prominently forward and demonstrated its truth in a volume which will doubtless form a landmark in the domain of zoological science.

We find even in the third edition of his "Origin of Species" the following passages :—" Natural selection can act only by taking advantage of slight successive variations; she can never take a leap, but must advance by short and slow steps." (p. 214.) Again he says:—"If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case." (p. 208.) He adds:—

"Every detail of structure in every living creature (making some little allowance for the direct action of physical conditions) may be viewed, either as having been of special use to some ancestral form, or as being now of special use to the descendants of this form —either directly, or indirectly through the complex laws of growth ;" and "if it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species, it would annihilate my theory, for such could not have been produced through natural selection." —p. 220

It is almost impossible for Mr. Darwin to have used words by which more thoroughly to stake the whole of his theory on the non-existence or non-action of causes of any moment other than natural selection. For why should such a phenomenon "annihilate his theory "? Because the very essence of his theory, as originally stated, is to recognize only the conservation of minute variations directly beneficial to the creature presenting them, by enabling it to obtain food, escape enemies, and propagate its kind. But once more he says :—

"We have seen that species at any one period are not indefinitely variable, and are not linked together by a multitude of intermediate gradations, partly because the process of natural selection will always be very slow, and will act, at any one time, only on a very few forms ; and partly because the very process of natural selection almost implies the continual supplanting and extinction of preceding and intermediate gradations."— p. 223.

Such are Mr. Darwin's earlier statements. At present we read as follows:—

"I now admit, after reading the essay by Nageli on plants, and the rem- rks by various authors with respect to animals, more especially those recently made by Professor Broca, that in the earlier editions of my ' Origin of Species' I probably attributed too much to the action of natural selection or the survival of the fittest." .... "I had not formerly sufficiently considered the existence of many structures which appear to be, as far as we can judge, neither beneficial nor injurious ; and this I believe to be one of the greatest oversights as yet detected in my work."—Descent of Man, vol. i. p. 152.

A still more remarkable admission is that in which he says, after referring to the action of both natural and sexual selection :—

"An unexplained residuum of change, per

haps a large one, must be left to the assumed action of those unknown agencies, which occasionally induce strongly marked and abrupt deviations of structure in our domestic productions."—vol. i. p. 154.

But perhaps the most glaring contradiction is presented by the following passage :—

"No doubt man, as well as every other animal, presents structures, which, as far as we can judge with our little knowledge, are not now of any service to him, nor have been so during any former period of his existence, either in relation to his general conditions of life, or of one sex to the other. Such structures cannot be accounted for by any form of selection, or by the inherited effects of the use and disuse of parts. We know, however, that many strange and strongly marked peculiarities of structure occasionally appear in our domesticated productions ; and if the unknown causes which produce them were to act more uniformly, they would probably become common to all the individuals of the species.''—vol. ii. p. 387.

Mr. Darwin, indeed, seems now to admit the existence of internal, innate powers, for he goes on to say :—

"We may hope hereafter to understand something about the causes of such occasional modifications, especially through the study of monstrosities." .... "In the greater number of cases we can only say that the cause of each slight variation and of each monstrosity lies much more in the nature or constitution of the organism* than in the nature of the surrounding conditions; though new and changed conditions certainly play an important part in exciting organic changes of all kinds."

Also, in a note (vol i. p. 223), he speaks of " incidental results of certain unknown differences in the constitution of the reproductive system."

Thus, then, it is admitted by our author that we may have "abrupt, strongly marked " changes, "neither beneficial nor injurious" to the creatures possessing them, produced "by unknown agencies" lying deep in " the nature or constitution of the organism," and which, if acting uniformly, would "probably" modify similarly "all the individuals of a species." If this is not an abandonment of " natural selection," it would be difficult to select terms more calculated to express it. But

* The italics in the quotations from Mr. Darwin's book in this article are, in almost all cases, ours and not the author's.

Mr. Darwin's admissions of error do not stop here. In the fifth edition of his "Origin of Species" (p. 104) he says, "Until reading an able and valuable article in the 'North British Review' (1867), I did not appreciate how rarely single variations, whether slight or strongly marked, could be perpetuated." Again: he was formerly "inclined to lay much stress on the principle of protection, as accounting for the less bright colors of female birds" (Descent of Man, vol. ii. p. 198); but now he speaks as if the correctness of his old conception of such colors being due to protection was unlikely. "Is it probable," he asks, "that the head of the female chaffinch, the crimson on the breast of the female bullfinch, the green of the female chaffinch, the crest of the female goldencrested wren, have all been rendered less bright by the slow process of selection for the sake of protection? / cannot think so." (vol. ii. p. 176.)

Once more Mr. Darwin shows us (vol. i. p. 125) how he has been over-hasty in attributing the development of certain structures to reversion. He remarks, "In my 'Variations of Animals under Domestication' (vol. ii. p. 57) I attributed the not very rare cases of supernumerary mamma: in women to reversion." "But Professor Preyer states that mamma erraticoz have been known to occur in other situations, even on the back; so that the force of my argument is greatly weakened or perhaps quite destroyed."

Finally, we have a postscript at the beginning of the second volume of the "Descent of Man" which contains an avowal more remarkable than even the passages already cited. He therein declares :—

"I have fallen into a serious and unfortunate error, in relation to the sexual differences of animals, in attempting to explain what seemed to me a singular coincidence in the late period of life at which the necessary variations have arisen in many cases, and the late period at which the sexual selection acts. The explanation given is wholly erroneous, as I have discovered by working out an illustration in figures."

While willingly paying a just tribute of esteem to the candor which dictated these several admissions, it would be idle to dissemble, and disingenuous not to declare, the amount of distrust with which such repeated over-hasty conclusions and errone

ous calculations inspire us. When their author comes before us anew, as he now does, with opinions and conclusions still more startling, and calculated in a yet greater degree to disturb convictions reposing upon the general consent of the majority of cultivated minds, we may well pause before we trust ourselves unreservedly to a guidance which thus again and again declares its own reiterated fallibility. Mr. Darwin's conclusions may be correct, but we feel we have now indeed a right to demand that they shall be proved before we assent to them; and that since what Mr. Darwin before declared '■'■must be," he now admits not only to be unnecessary but untrue, we may justly regard with extreme distnist the numerous statements and calculations which, in the "Descent of Man," are avowedly recommended by a mere "may be." This is the more necessary, as the author, starting at first with an avowed hypothesis, constantly asserts it as an undoubted fact, and claims for it, somewhat in the spirit of a theologian, that it should be received as an article of faith. Thus the formidable objection to Mr. Darwin's theory, that the great break in the organic chain between man and his nearest allies, which cannot be bridged over by any extinct or living species, is answered simply by an appeal " to a belief in the general principle of evolution" (vol. i. p. 200), or by a confident statement that "we have every reason to believe that breaks in the series are simpiy the result of many forms having become extinct." (vol. i. p. 187.) So, in like manner, we are assured that " the early progenitors of man were, no doubt, once covered with hair, both sexes having beards; their ears were pointed and capable of movement; and their bodies were provided with a tail, having the proper muscles." (vol. i. p. 206.) And, finally, we are told, with a dogmatism little worthy of a philosopher, that, "unless we wilfully close our eyes" we must recognize our parentage.—vol. i. p. 213.

These are hard words ; and, even at the risk of being accused of wilful blindness, we shall now proceed, with an unbiassed and unprejudiced mind, to examine carefully the arguments upon which Mr. Darwin's theoiy rests. Must we acknowledge that "man with all his noble qualities, with sympathy which feels for the most debased, with benevolence which extends

« 이전계속 »