Popular Science Monthly/Volume 76/January 1910/Darwin's Probable Place in Future Biology

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DARWIN'S PROBABLE PLACE IN FUTURE BIOLOGY
By Professor WILLIAM E. RITTER

MARINE BIOLOGICAL STATION OF SAN DIEGO, CALIFORNIA

THIS centenary of Darwin's birth and semi-centenary of the publication of "The Origin of Species" will stimulate greater interest than ever in the illustrious naturalist's life and work. It may be hoped that the retrospective mood and generous spirit wont to pervade commemorative periods may contribute to better understanding and juster estimate of his achievements.

A strong current in biological thought is now running counter to belief in natural selection as an adequate explanation of evolution. One not at home in the biological literature of the day has but to read such general books as Morgan's "Evolution and Adaptation" and Kellogg's "Darwinism To-day" to feel the force of this current. That it is destined to wax stronger appears certain. Until its meaning is rightly seen it can but work injuriously to Darwin's fame.

Such productions as Dennert's "At the Deathbed of Darwinism" are symptomatic, though peevish, irreverent and false. They indicate disease somewhere in the body of evolutional doctrine. According to my diagnosis, the disease is seated near the vitals of the body and the name by which it is known is neo-Darwinism. It is a morbific growth and only its removal can restore the patient to health.

For a full generation, trade-marked expounders of evolution have insisted that only natural selection is true Darwinism. Powerful voices among these have said that natural selection is the full explanation of evolution, and on this basis are known as neo-Darwinians. By general assent natural selection becomes Darwinism, and by high authority Darwinism becomes neo-Darwinism. Consequently, now that neo-Darwinism has had time to come near its perdition, it not unnaturally seems to the little discerning to be dragging all evolution with it.

What did Darwin really do? Let us ask the question during this first centennial year of his birth, as though expecting the answer from the second centennial of his natal day.

To begin with, he gave us one of the noblest examples of a life devoted to search for truth that the modern world has seen. Splendid as are his works, more splendid still was the man. Every human life—every life—viewed from the standpoint of the larger, truer biology, must be seen to be greater than any of its works, for its works are but parts of the whole, and in biology, as elsewhere, a part is less than the whole. Viewed from the eminence of his own example, we shall see where he fell short and was led into error with as even an eye as we shall see what he did that must endure as long as science itself shall endure.

Directing our question to the works themselves, this is the answer that comes prompt and clear: Darwin convinced everybody competent to judge the case on its merits that new kinds of plants and animals originate naturally, not miraculously. He not only convinced experts of this truth, but he gained for it a secure place in the great, irresistible tide of common thought and life. Such was his supreme achievement. Many of his ardent disciples have not been content to accept this, for them, too modest appraisement of his work. They have said his true greatness lies not in his having established the "mere fact of evolution," but that he explained that fact—that he discovered the how and why of evolution.

The verdict of inexorable time will refuse to Darwin the glory of having really explained the origin of new species of organisms. It will allow that he did much in this direction, but not greatly more than others past and future have done and will do. Fame's recompense so far as this is concerned, Darwin will have to take share and share alike with many a fellow workman.

The question we have to consider is: Was establishing the truth of evolution an achievement of such magnitude as to enroll its accomplisher among those who belong beyond peradventure to all the ages? My answer is, yes. The reason for the answer, reduced to smallest compass, is that in doing this Darwin brought into the fold of observation and rational thought the latest and greatest ingredient of reliance on the order of nature, of belief in the infinite whole of things, of faith in the dignity and destiny of man. We here approach one of those vast realms of truth and human concern, the earliest visions of which are always gained by those geniuses known to us as prophets and poets. "Faith is the substance of things not seen," said in essence the philosopher disciple.

Faith, that meets ten thousand cheats
Yet drops no jot of Faith!
Devil and brute Thou dost transmute
To higher, lordlier show,
Who art in sooth that lovely Truth
The careless angels know!

So speaks England's foremost living poet.

Darwin, more perhaps than any other single man of science, contributed to the incarnation of the truth presented here as vision; and only in so far as it is incarnated does it become daily bread for common men. Through such incarnations alone are men convinced that no lawlessness exists or ever has existed anywhere in nature, that nothing ever happens or ever has happened of such character as to wholly thwart and put to confusion the perfectly sober, the truly devout mind of man. When in the future laborious science shall have made itself and common humanity more fully and securely possessed of this truth, then will Darwin's labors stand revealed in their true grandeur.

Biologists are wont to say that evolution is now universally accepted. To see how far this is from true in a thoroughgoing sense, one has but to recall that Alfred Russel Wallace, the co-discoverer with Darwin of natural selection, denies evolution for part of man; and that an untutored, unbalanced woman, Mrs. Eddy, founds a religious cult, one cornerstone of which is an implied denial of universal evolution, which cult gets in a generation a larger following than any other started in recent times.

It is impossible to argue out the full case of the universality of organic evolution here. To do so would lead into the lowermost subtleties of technical science and logical process. A few of its surface strata must suffice for now.

Go to history to learn about the development of great ideas in physical science and you will see how, over and over again, this development has run much the same course. Three distinctly characterized stages are seen in these developments. The first is that of intuitive perception; of spontaneous, vague, fragmentary statement; of badly jumbled observation and fancy, thoughtfulness and vagary, truth and error. During this time scientific proof in the strict sense hardly appears at all.

Then comes the stage of what might be called discursive demonstration. The advance of this beyond the first is enormous in both essentials and consequences. Its greatest significance lies in the fact that the mind's ability to distinguish between demonstrated truth and possible truth has now found itself. The difference between generalizations and theories about nature that rest on objective experience, and such as may possibly be true, though they have no experiential basis, now begins to be clearly seen.

Finally comes the third stage, fundamentally differentiated from the second by the fact that the mind has at last grasped the vital meaning of quantitative values in demonstration. Evidence is now no longer primarily discursive and incidentally mathematical, but is essentially quantitative as well as qualitative. This quantitative stage biology is now barely on the threshold of.

It was Darwin more than any other biologist who carried the idea of evolution into the second of these three stages. Failure to grasp the full significance of this forward step must mean failure to assign to him his true place in the history of thought.

It has been pointed out time and time again that the evolutionary interpretation of living nature did not originate with Darwin; that in fact it is as old as Greek philosophy at least. And because, so the view has run, he was not a discoverer in this but only a promoter, there was not sufficient ground upon which to build a truly immortal fame. Such fame, so it has been maintained, could be reached only through a supreme original discovery. Such a discovery was natural selection, the greatness of which consisted in its being the chief if not the sole explanation of evolution. Now, however, we are coming to see that Darwin erred, and that some of his followers have erred more, as to the power of natural selection in species transformation.[1]

It will require some generations yet to find out even approximately what rôle the wonderful process of struggle and selection plays in species-making. But it is becoming clear in part wherein and why Darwin and, following him, all the rest of us, have gone so wide of the mark concerning it. The subject is too vast to touch more than summarily here.

It is the very essence of the human mind to inquire after the causes of whatever happens in this world of ours. It is the essence of science to hold that these causes are natural, not supernatural. Darwin became convinced that species arise naturally while yet the philosophy of living things in which he had been nurtured contained practically nothing concerning any natural cause that could be assigned to species production. Special or supernatural causation was held as a dogma rather in default of evidence of natural causes than from proof of supernatural ones. So religious superstition and dogmatism had a free field here. Darwin's naturalist instincts said: "Since species arise naturally, natural causes sufficient therefor must exist. If they are natural they are ascertainable. I will search for them." So he set about the task with the result that all the world knows. He discovered the process called by him natural selection, and saw it to be a real cause in the generation of species.

Now comes the greatly important point. I have said Darwin carried the evolution idea into the second of three stages through which interpretations of the world usually run; the stage, namely, of qualitative, discursive demonstration. Not having yet reached the third stage, that of quantitative demonstration, he had no way of measuring in a mathematical sense the efficiency of natural selection. He could establish no quantitative relation between cause and effect. In fact he did not look at the problem from the quantitative standpoint in the proper sense at all. So it was almost inevitable that he should exaggerate the power of the cause he had discovered. And see the essential nature of this exaggeration: Before Darwin supernatural causes were held to account for the origin of species. But supernatural causes are always adequate, final. Supernaturalist doctrines are always absolutist doctrines. Therefore effort to make natural selection supplant supernatural causation is effort to make it, too, adequate, final. Attempt to make natural selection the sole, the complete cause of evolution, and you become a finalist, an absolutist. In a word you retain the essence of supernaturalism. Absolutist natural selectionism is only a disguised

form of supernaturalism. It is failure to recognize that by its essential nature physical science can deal with causation only piecemeal; that it can only grasp causes one by one and can never get them all. Absolutism is supernaturalism, and under whatever disguise is the seemingly everlasting and implacable foe, not merely of inductive science, but of rational conduct. Would that somebody might set forth this truth in words so hot that they should burn themselves ineffacably into the philosophy, the science and the daily round of common life of our and of all future generations of men! With what serenity some of our best accredited men of science are themselves striving, and advising the neophytes in science to strive, for the solution of ultimate problems! So long as this is so there is necessity for, and will surely always be, theosophy, christian science and the whole retinue of psychic absolutisms. The one brand of finality is but the counterpoise of the other.

Though still in the second stage of idea-development as regards natural selection, a few important truths about the process are being revealed to us that Darwin overlooked, or did not sufficiently emphasize. In the first place, while he soon saw that natural selection could not be the sole cause of evolution, and while he recognized it to be a cause of a general nature, he never grasped in its full meaning the truth that there are not one, nor a few, nor even many, but literally an infinite number of causes at work in the production of species.

It is curious, once one comes to think of it, that Darwin and the rest of us should have talked so long and so absorbedly about one or a few "factors" of evolution when the demands of rigorous science are that there shall be at least as many causes as there are species. Were this not so the same cause would produce different effects, and that would make biology a hocus-pocus indeed. Supernatural causes would be quite as amenable to science as such natural ones. Trouble has befallen us here from not having listened with due attention to what David Hume has told us about causes. His definition of a cause as "an object followed by another, where, if the first had not been, the second never had existed," has not sunk deeply enough into our minds.

The course by which we have seemed to keep out of this limbo has been exactly one element in our discomfiture. We have said "Why, to be sure natural selection always takes variation and heredity for granted. Darwin made that clear enough." But when we make the causes of evolution our problem, why not face the music squarely? Why not make sure of the causes first and classify and name them afterwards? That is the way we proceed in systematic botany and zoology.

The truth is, natural selection itself is a great bundle of causes some of which are different in each particular case to which the bundle applies, so must be separately investigated for each particular species.

Does any Allmacht natural selectionist believe in his heart of hearts that even an approximate consensus of opinion among biologists will ever issue from such general discussion of the "natural selection factor" as has been carried on during the last half century? I do not think so. The most that can be said for such views is that they stimulate research. But there is an aphorism in hygiene about over stimulation that ought not to be forgotten even in science, when stimulants are advocated.

What more prophetic utterance of Darwin's can be found than that made to Wallace after he had thought over natural selection for twenty years? "My work," he said, "will not fix or settle anything."

Another important matter that Darwin never laid hold upon with sufficient grip is the great significance of struggle aside from its role in species production. The numberless things that struggle may accomplish short of killing somebody, did not greatly attract his attention. From his standpoint struggle short of life and death struggle seems not to have counted for much. So in his writings struggle almost always appears as "struggle for existence."

Nature is exactly a vast system of parts, each part having a nature of its own, but at the same time being dependent upon innumerable other parts.

"Natural selection" (the expression has for the most part been restricted to the living world, but there is no essential reason why it should be. It would be quite as explanatory of the process of origination, applied in the inorganic, as in the organic, realm) is that complex of operations by which natural bodies get so located that the capabilities of portions of nature for doing their part toward the sustentation of other portions are utilized to the best advantage. Otherwise stated, it is the method by which organisms become arranged in nature according to their special needs and merits. In this operation, inconvenience, injury and destruction often result. But such results are among others, rather than the end and aim, the total result of the process. In many cases, though by no means in all, it must play a large part in determining the characteristics, especially in late life, of individual organisms. In a word, natural selection is probably one vera causa in species formation. In what instances it has been thus influential, and how far this influence has gone, are matters to be ascertained, as far as possible, in each particular case. If Greenland has the wherewithal to support men, in however meager and cheerless a way, it is at least as reasonable to conceive Mother Nature (if one is to personify nature) as congratulating herself that she has some men able to accept such bounty and like it, as to conceive her as fiendishly gloating, or filled with impotent grief, as the case may be, over having crowded a few of her mortal beings off into so hard a quarter. Darwin did not view the process in this light very much

Again, a phenomenon of organisms that Darwin appealed to in elaborating his hypothesis is their prodigality in generation. He almost always looked at this from the standpoint of the inevitable crowding and struggle, carnage, famine and death, that result.

But there is another direction from which this prodigality must be viewed, namely, from that of the absolute interdependence, the reciprocal relationships that prevail among organisms. Though always consumers, organisms are likewise always producers, and are producers in larger measure titan is necessary for their own perpetuity and best interests. "Every species is its own worst enemy." There is consequently, on the whole, a surplusage of product as regards both the individual and the kind. So it comes about that the consumption that is going on is in part a consumption of surplus. Do not understand me to say that this is the correct view of the matter while the other is incorrect. Both views are true, and hence exclusive or unbalanced attention to either is inadequate.

Our conclusion amounts to this: Darwin's fame will grow in luster parsi passu with growing recognition that he did not discover the cause of evolution. This paradoxical statement ought to be viewed askance, as all paradoxes should be. But see its justification. We biologists will be able to approach the important truth of struggle in animate nature with minds open for evidence of every sort as to its meaning when we shall have broken up the habit—for habit it has surely become—of attributing to it powers and capabilities beyond those it actually has.

We turn again to the greater side of Darwin's work. Transform yourself in imagination to a state of mind that holds all the natural kinds of plants and animals by which you are daily surrounded, to be each an independent miraculous creation, to be objects, that is, concerning the origin of which no human being shall ever gain the slightest real knowledge. Thus transform yourself, and then, and only then, may you grasp the momentous significance of the extension of the domain of law in the physical world wrought by the establishment of the "mere fact" of evolution.

Since my position makes so much of the distinction between establishing the truth of evolution and discovering the adequate cause of evolution I must justify myself more fully. Let us ask how sharply Darwin himself made this distinction, and how he appraised his own work from this standpoint.

That Darwin was convinced of the fact of descent with modification before he had any working hypothesis as to its cause, in other words, that he was an evolutionist before he was a natural selectionist has not been given due weight, though perhaps is well enough known. Let us look briefly at the evidence for this statement.

The aid of Francis Darwin, his son is important here. The chief sources of information are the two editions of the "Journal of Researches," and his early notes and queries printed after his death. The first edition of the "Journal" was finished in 1838, though not published till the following year. It was in October, 1838, that he read Malthus's "Essay on Population," the incident that started him on the road to natural selection. The first edition of the "Journal" was, consequently, practically uninfluenced by his famous causal hypothesis.

Discussing this early period of his father's ideas, the son writes:

After reading the second edition of the "Journal" (published in 1845) we find a strong sense of surprise at how far developed were his views in 1837.[2]

It will be observed that 1837 was the year before the Malthus essay was read. But the evidence from posthumous notes is more to the point. The son remarks:

We are enabled to form an opinion on this point from the note-books in which he wrote down detached thoughts and queries.

From these I quote a few.

Propagation explains why modern animals same type as extinct, which is law, almost proved.

If we choose to let conjecture run wild, then animals, our fellow brethren in pain, disease, death, suffering and famine—our slaves in the most laborious works, our companions in our amusements—they partake (of) our origin in one common ancestor—we all may be melted together.

It is a wonderful fact, horse, elephant, and mastodon, dying out about same time in such different quarters.

They die, without they change, like golden pippins; it is a generation of species like generation of indivduals.

. . . so with useless wings under elytra of beetles—born from beetles with wings, and modified; if simple creation merely, would have been without them.

So much for evidence that Darwin was an evolutionist before he was a natural selectionist or had any other causal hypothesis. As to the relative value set by him on his part in establishing the "mere fact" of evolution, and his effort to explanation of that fact, the son's testimony is again important. He writes:

It comes out very clearly that. . . my father did not rejoice over the success of his special view of evolution, viz., that modification is mainly due to natural selection; on the contrary, he felt strongly that the really important point was that the doctrine of Descent should be accepted.[3]

Any one who knows Darwin's life-work in spirit as well as in letter will accept this statement unhesitatingly. Utterances of like import by Darwin himself are numerous. For brevity's sake I give but one. Writing to Asa Gray in 1863, he said:

I have sometimes almost wished that Lyell had pronounced against me. When I say "me," I only mean change of species by descent. That seems to me the turning-point. Personally, of course, I care much about natural selection, but that seems to me utterly unimportant, compared to the question of Creation or Modification.[4]

How vitally it concerns both justice to Darwin and sound views of 'life generally that technical biology and lay understanding alike should face right in this matter!

But if natural selection is really unimportant as contrasted with evolution, how has it come to occupy so large a part of the stage? How is it that accredited expounders of evolution the world over have insisted that natural selection is the only genuine brand of Darwinism, and must be the corner-stone of Darwin's greatness?

The elements entering into the answer are manifold. Three have been indicated already. These may be summarized thus:

1. Undue weight has been attached to the fact that the idea of evolution did not originate with Darwin but is "old as thought itself." Absence of adequate experiential evidence for the truth of this vague idea until Darwin produced it, has not been given enough importance.

2. With the passage of time and our familiarization with the idea of evolution there has been a tendency to minimize the importance of the grip in which miraculous creation held men's minds up to the Darwinian era.

3. A wholly unwarranted importance has been attached to the part played by the natural selection hypothesis in promoting belief in the truth of evolution. Darwin became an evolutionist before he was a natural selectionist, and there is good reason for supposing the rest of us would have gone with him had he never thought of natural selection.

Other elements in the answer to our query must now be taken up. In the first place, Darwin himself placed a heavier burden of causal efficiency on his hypothesis than it is able to bear. This he at length acknowledged in his usual open, honest way. Perhaps his most positive statement to this effect is in "The Descent of Man."[5] It has often been quoted, though hardly enough heeded. He says:

I now admit, after reading the essay by Nägeli on plants, and the remarks' of 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 have altered the fifth edition of the Origin so as to confine my remarks to adaptive changes in structure. 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.

But the mischief had been done, and Darwin's inability to remedy it troubled him not a little.

Let us see if there is anything either in his argument itself, or in his mode of handling it, that set the tide of his influence wrong beyond his power of righting.

For one thing, Darwin was unfortunate in the title chosen for his foundation book. "The Origin of Species by Means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life" is the title in full. A little reflection discovers ambiguity in this. Is the author concerned primarily with the origin of species or with a particular way of accounting for their origin? One piece of internal evidence of a general character is to the effect that the second alternative is the true one. The explanatory hypothesis is treated first and occupies fully half the work, while the observed proofs of origin by natural modification are given second place. Why did not Darwin present his proofs of evolution first and his hypothesis second, thus making his title and order of treatment correspond? The fact is he wavered as to where the emphasis should be laid touching the relative importance of the two objects he tells us he had in view in writing the "Origin." This wavering he never to the end of his life was able to fully correct.

We can point out specifically how this equivocal meaning of the title has operated to make Darwin a natural selectionist in a sense that he himself resisted. One biologist, a particularly strong pro-natural selectionist, has written:

This title is of interest, as has been pointed out by Professor E. Ray Lankester, in relation to the controversy upon the exact meaning of the word "Darwinism." Some writers have argued that the term "Darwinism" includes the whole of the causes of evolution accepted by Darwin—the supposed inherited effects of use and disuse and the direct influence of environment, which find a subordinate place in the "Origin," as well as natural selection, which is the real subject of the book and which is fully defined in the title. It would seem appropriate to use the term "Darwinism" as Wallace uses it, to indicate the causes of evolution which were suggested by Darwin himself, excluding those supposed causes which had been previously brought forward by earlier writers, and especially by Lamarck.[6] (Italics mine.)

The large conception that "Darwinism" might be "evolutionism" has no place in this author's mind, so it would seem from this statement. Darwinism according to such a view must have sole reference to certain specified causes of evolution instead of evolution itself through any and all causes that may be behind it. The power of mental bias to lead men unconsciously wrong is not often more strikingly illustrated than in this; for here it goes to the extent of making professed followers and admirers of Darwin do him grave injustice. What meaning can Darwinians who thus circumscribe "Darwinism" put into such of their prophet's language as this?

I may be permitted to say, as some excuse, that I had two distinct objects in view, firstly, to show that species had not been separately created, and secondly, that natural selection had been the chief agent of change, though largely aided by the inherited effects of habit, and slightly by the direct action of the surrounding conditions. . . . Some of those who admit the principle of evolution, but reject natural selection, seem to forget. . . that I had the above two objects in view; hence if I have erred in giving natural selection great power, which I am far from admitting, or in having exaggerated its power, which is in itself probable, I have at least, as I hope, done good service in aiding to overthrow the dogma of separate creations.[7] (Italics mine.)

The kernel of the bias that has done so much harm is not difficult to find. Pursuit of the question as to which one of several supposed causes of evolution is the whole cause, has been so ardent that the extremists among the upholders of the particular cause discovered by Darwin, have been blinded to what he himself has declared to have been the first of two objects in writing the "Origin of Species."

The question of what "Darwinism proper" shall be is relatively insignificant. If one's linguistic taste favors making Darwinism apply to the particular causal principle discovered by Darwin, well and good. Then Darwinism is of no great moment, relatively. On the other hand, if one's taste is more catholic, he will prefer to have Darwinism apply to the really great thing that Darwin did, and the term will mean organic evolution, the unfailing reign of law in the origination of living beings, one of the greatest truths of nature, when its establishment shall be complete, that the mind of man has yet possessed itself of.

While Darwin himself was not without responsibility for this narrowing, withering view of what "Darwinism really is," by far the greater responsibility rests upon two other men, namely, Alfred Eussel Wallace and August Weismann. These two, each truly eminent in his own right, have been looked upon by a too little-discerning biological period as those upon whom the "mantle of Darwin" has fallen. Let us away once and for all with this false and flimsy notion about any man's mantle falling upon some other man! Every man's mantle, be he great or small, is his own alone, and goes to his grave with him, or ought to be allowed to. What kind of self-esteem is that which wants the distinction of wearing another's clothes? Mr. Wallace has certain interesting biological ideas and so has Professor Weismann. The ideas of both have much in common with ideas held by Darwin. Both men have worked out their ideas as best they could, greatly influenced no doubt by the methods and writings of Darwin. But Mr. Wallace's ideas are his, Professor Weismann's are his and Mr. Darwin's were, and shall be, his. Let us take them all and estimate them on this basis. In so far as all three or any two sets are alike, let us recognize the resemblance; but in so far as they differ, let us see the differences also. The relation of Weismann's doctrines to Darwin's I merely touch upon here. It should be recalled that Weismann is a neo-Darwinian of the Neodarwinians so far as natural selection goes. By far the most important nexus between Darwin and Weismann, when it comes to the deeper reaches of biological theory, is through Darwin's pangenesis hypothesis and Weismann's germ-plasm-determinant doctrine. This I treat at length elsewhere. It may be left to one side here because of its relative unimportance as touching Darwin's work proper, though of fundamental importance to an exhaustive discussion of the present status of biological philosophy.

Mr. Wallace's ungrudging recognition of Darwin's towering genius as compared with his own is one of the particularly bright and inspiriting examples of what personal relationship between men may be. And to Mr. Wallace is the greater honor because his was the lesser intellectual endowment and achievement.

Turning from Mr. Wallace's beautifully deferential attitude toward his friend, to the facts upon which he based this, what do we find?

We have already seen that Darwin had convinced himself of the truth of descent with modification before he thought of natural selection, and that it was the essay of Malthus on population that gave him the idea of struggle and survival. On December 22, 1857, he said in a letter to Mr. Wallace:

My work at which I have now been at work more or less for twenty years, will not fix or settle anything; but I hope it will aid by giving a large collection of facts, with one definite end.[8] (Italics mine.)

It should be remembered that Malthus's essay was read in 1837.

The circumstances under which Mr. Wallace became the co-propounder of evolution and co-discoverer of natural selection are told by himself. He says:

After writing the preceding paper (On the Law which has Regulated the Introduction of New Species) the question of how changes in species could have been brought about was rarely out of my mind, but no satisfactory conclusion was reached till February, 1858. At that time I was suffering from a rather severe attack of intermittent fever at Ternate in the Moluccas, and one day, while lying on my bed during the cold fit, wrapped in blankets, though the thermometer was 88° Fahrenheit, the problem again presented itself to me, and something led me to think of the "positive checks" described by Malthus in his "Essay on Population," a work I had read several years before, and which had made a deep and permanent impression on my mind. These checks—war, disease, famine and the like—must, it occurred to me, act on animals as well as man. Then I thought of the enormously rapid multiplication of animals, causing these checks to be much more effective in them than in the case of man; and while pondering vaguely upon this fact there suddenly flashed upon me the idea of the survival of the fittest—that the individuals removed by these checks must be on the whole inferior to those that survived. In the two hours that elapsed before my ague fit was over, I had thought out almost the whole of the theory, and the same evening I sketched the draft of my paper, and in the two succeeding evenings wrote it out in full, and sent it by the next post to Mr. Darwin.

Then Mr. Wallace goes on to speak of the letter from Mr. Darwin containing the quotation given above, and says:

The words I have italicised (the same italicized in my quotation) and the whole tone of his letters, led me to conclude that he had arrived at no definite view as to the origin of species, and I fully anticipated that my theory would be new to him, because it seemed to me to settle a great deal.[9]

There you have the difference between the two men's minds, at least in their attitude toward survival of the fittest, put in a nut-shell by "Wallace himself. What seemed to him from two days' reflection able "to settle a great deal," seemed to Darwin after twenty years' reflection, not able to "fix or settle anything."

Another highly instructive exemplification of this difference is furnished by a discussion between the two on natural selection and sterility. This is given us in "More Letters of Charles Darwin," letters 209-216, the correspondence having been carried on in 1868. Wallace presents (letter 211) "what appears to me a demonstration on your own principles, that natural selection could produce sterility of hybrids." Darwin's general position on the point is well indicated in letter 213. He says:

I have been considering the terrible problem. Let me first say that no man could have more earnestly wished for the success of Natural Selection in regard to sterility than I did, and when I considered a general statement (as in your last note) I always felt sure it could be worked out, but always failed in detail. The cause being, as I believe, that Natural Selection can not effect what is not good for the individual, including in this term a social community.

Although Darwin was sure there was something wrong in Wallace's argument, and was not budged an inch by it, he seems not to have recognized its logical preposterousness. He did not explicitly point out to Mr. Wallace that since over-productivity, or geometrical increase, is one of the fundamental presuppositions of natural selection, to suppose natural selection could produce sterility would make it capable of negativing one of its own presuppositions. Stating the matter figuratively, Darwin saw no logical difficulty in the supposition that natural selection might commit suicide. With him it was merely a question of whether it does this or not, and he could not make out from the evidence that it does. But he did not see that Wallace's argument carried out consistently would not only enable natural selection to commit suicide, but in reality would make it able to prevent itself from coming into existence.

The scope and balance of Darwin's mind are seen nowhere to better advantage than in his efforts to prevent his own causal hypothesis from going beyond bounds. Nevertheless the true inwardness of the difference between himself and those who later were to produce the socalled neo-Darwinian school, the school founded on the omnipotence of natural selection, is nowhere better seen than in his position relative to the application of natural selection to man. While one of Darwin's greatest achievements was his proximate demonstration that man is not a being wholly cut off by his origin from the rest of nature, and while he saw prophetically rather than rigorously, that the final test and goal of all science, evolutional biology with the rest, must be its ability to help man to understand and guide himself in the full scope of his nature, he did not see, at any rate clearly, what must be the inevitable outcome of trying to make struggle and selection explain fully the evolutionary process.

He failed to. see the deeper meaning of the circumstance that it must work toward making the brightness and beauty of the living world appear as though seen through a somber-colored distorting-surfaced, glass screen.

He did not see that it must foster a sort of egoism that would make the golden rule as dead on the statute books of human relationship as a mastodon in a Siberian ice-bed.[10]

The golden rule in its ethical significance does not now concern me. It is as a biological phenomenon that I am looking at it. Living organisms, and each one in its totality or so much of its totality as I can reach, are my biological data. Should I study the honey bee or the American beaver I should be adjudged an unsound biologist were I to draw sweeping conclusions about them, in which little or no cognizance should be taken of some of their most prominent traits, as for instance, of their community habits. Or still more should I be adjudged unsound were I to enter upon the study with already-fixed conceptions about instincts, let us say, that would lead me to overlook, or have to explain away, certain prominent traits.

The golden-rule trait is one that man actually presents no less surely than is the iron-rule trait. There it is, written into his history and stamped upon his behavior almost everywhere.

It is exactly the office of biology as it undertakes the study of man to frame its explanatory theories large enough to take in whatever it finds characteristic of him. If man really is a part of nature, as an unflinching evolution seems to say he is; and if natural causation really can be relied upon throughout the world, then there must be something wrong with a causal theory of evolution that not only makes no provision for, but actually negates, some of the most fundamental qualities that man's nature presents. Let us not fail to see that Huxley's trouble over the conflict between the cosmic and ethical processes involves not merely natural selection, but goes to the vitals of evolution and natural law itself. This is a mighty question.

He did not perceive that it would enable pride, avarice, cruelty and injustice to draw the sacred mantle of science about them.

Read the encyclopædias of biography from A to Z and you will find portrayed there no warmer hearted, more genuine, generous souled, open minded man than was Charles Darwin. But when you read his life for aid in understanding his work, do not fail to read the whole of it. He was a nature-loving, country-dwelling English gentleman of the best type—not a gentleman in the political and social sense, but in the manly sense. Further, he was to the very marrow of his bones an English naturalist as well as an English gentleman. He inherited the instincts of the naturalist and likewise the worldly wherewithal that enabled him to follow his bent without let or hindrance. So it was that the naturalist's standpoint was literally both first and second nature to him. Rarely is it the fortune of a scientific career to run through from beginning to end so strictly along the lines of instinctive choice and least resistance, as Darwin's ran. It is not too much to say that Darwin knew nothing of that sort of discipline that comes from compelling one's self to do things which initially he does not like. It is well known that even in biology, the realm of science to which by nature he so clearly belonged, he as a youth dodged those of its disciplines that he did not like, however basal they might be. For example, when trying himself out as a medical student, he did not like anatomy, so anatomy he did not study in any serious way.

Comprehensive and well balanced as became his scientific efforts and knowledge, these were always so within the bounds of predilection rather than of logical and philosophical compulsion. This I believe to be the weightiest of several reasons why Darwin saw so imperfectly the direction in which the struggle-selection principle must lead those who misunderstand and exaggerate it.

Had he grounded himself in mathematics, psychology and ethics, not necessarily as fully but as sympathetically as he did in natural history, he might have anticipated, at least in outline, what has actually happened. He might have foreseen the fate of his friend Huxley, who found himself driven to attempt the rehabilitation under an altered nomenclature of the old, old conception of the world as a battle ground, with man the chief prize, where an infinite, beneficent God is field-marshal on one side, and an infinite, malevolent devil leads the hosts on the other; and of his friend Wallace who landed finally in the shadow-realms of disembodied spirits and ghosts; and of such strong-timbered, though loosely-framed minds as that of Friedrich Nietzsche,[11] for whom the way of a self-annihilating individualism and utilitarianism, could hardly be other than the way to the mad-house; and finally of numberless mediumly endowed souls in whom such doctrines could not fail to beget a pusillanimous indifferentism toward all human weal excepting such as can be seen to be directly advantageous to one's own weal.

We may be sure that the volumes of social and ethical doctrine that have been written from, not the Darwinian, but the neo-Darwinian, standpoint, and the still larger volumes of unethical practise that have consciously and unconsciously been instigated and justified from the same standpoint, would have brought inexpressible anguish to the noble spirit of Charles Darwin, could he but have seen them in full flower and fruit.

My conclusion then as to Darwin's probable place in future biology may be summed up thus: Darwin has been frequently called the Newton of Biology. Not so! Newton discovered a great mathematical, that is, exactly expressible law of nature. Darwin found no such law. For its real Newton, biology will probably have to wait another fifty years at least. When he appears he will be a mathematical biologist.

If the counterpart of Darwin in inorganic science is to be sought, Copernicus rather than Newton would be the man. The revolution in men's attitude toward nature wrought by each of these was much the same, both in kind and magnitude, and both men's names will grow brighter on the pages of history so long as mortals are stirred by the beauty of orderliness and law, and by what is lovely in form and color and motion; so long as they have feelings of gratitude and obligation for what has gone to the making of themselves and the things they enjoy, what they are; and so long as their faith in the Infinite Whole of Things abides and waxes stronger.

    the misshapen legs, cloven feet, pendulous lips, and curiously mounded back of the sleepy beast, the old man turned away with the remark "there ain't no such animal!" I may be wrong as my sources of knowledge are limited, but I believe a considerable number of British naturalists will refuse to let Sir E. Ray take them with him into the class with the Jersey farmer.

  1. Since the manuscript of this essay went to the publisher, the celebrations of Darwin's birth have been held at Cambridge University. On one of the occasions Sir E. Ray Lankester is reported (Nature, July 1) to have said:

    "I think that the one thing about Charles Darwin which the large majority of British naturalists would wish to be to-day proclaimed, in the first place—with no doubtful or qualifying phrase—is that, in their judgment, after these fifty years of examination and testing, his 'theory of the origin of species by means of natural selection or the preservation of favored races in the struggle for life' remains whole and sound and convincing in spite of every attempt to upset it."

    Also in the meantime the paper by Drs. Raymond Pearl and Frank M. Surface, entitled "A Biometrical Study of Egg Production in the Domestic Fowl" (Bull. 110, part 1, Bureau of Animal Industry, U. S. Dept. of Agricul.) has reached me.

    From the mathematical treatment of the data collected through eight years of rigid selective breeding aimed at the improvement of egg production in chickens, the authors say: "It is shown that during the period covered by the statistics (1899-1907), which covers practically the whole period of the breeding experiment, there has been, apart from fluctuations up and down in individual years, a small but steady decrease in the mean or average annual egg production."

    "The percentage of extremely high layers (producing more than 195 eggs in the pullet year) in the flock decreased during the period from 1899 to 1907. The percentage of exceptionally poor layers (producing less than 45 eggs in the pullet year) in the flock increased during the same period."

    And concluding, the authors say: "It is shown that the intensity or stringency of selection became relatively greater during the progress of the experiment, though the absolute standard of selection remained the same. It is further shown that there is no evidence that the selective breeding practiced has improved the strain in respect to egg production. On the contrary, the data show that (a) the mean egg production has diminished during the experiment; (b) the variability in egg production has remained unchanged, and (c) in the last years of the experiment relatively slight environmental changes caused very marked changes in the flock productiveness. This is obviously inconsistent with the view that any particular type of egg production has in any way been fixed in a strain by breeding."

    Reading Lankester's statement in the light of this work at the Maine Agricultural Experiment Station, and of several other late researches of like import but less demonstrative value, I am, after the manner of Abraham Lincoln, reminded of a story: A Jersey farmer on his first visit to a menagerie came upon the dromedary. After scrutinizing for a long time in amazed silence

  2. "Letters," I., p. 367.
  3. "Letters," II., p. 163.
  4. "Letters," II., p. 163.
  5. I., p. 146.
  6. "Poulton, "Charles Darwin," p. 99.
  7. "Descent," I., p. 147.
  8. "Letters," I., p. 467.
  9. Poulton, "Darwinism," p. 88.
  10. My point here could hardly be misunderstood were it possible to read these statements properly set in the general discussion to which they belong.
  11. This does not necessarily mean that I take sides in the controversy as to the extent of Darwin's direct influence on Nietzsche. From my standpoint it matters little, if it be true, that Nietzsche never understood natural selection. The case has to be viewed in a much broader way. Nietzsche's ethics is one precipitate, so to speak, out of the same solution that Darwin's famous hypothesis came from. This solution filled the atmosphere of the whole western world for at least a half century before these two precipitates were thrown down. The essence of this solution was not so much an exaggerated individualism as it was an individualism waging its warfare within itself, i. e., with no supreme outside judge and power to guide and check, to approve fair fighting and punish unfair, and to direct the whole to some glorious end. Whatever Nietzsche's "Super-man" may be, this much is certain: It, or he, is man-, not God-conceived, and is to be man-, not God-created.

    Nietzsche's enterprise made it necessary for him to kill God thoroughly. While even the suggestion of such a thing was abhorrent to Darwin, it is nevertheless true that among the most trusted weapons used by Nietzsche in his killing, were the very ones of individualism and conflict used by Darwin, and it matters not so far as my main point is concerned, whether Nietzsche got his instruments from Darwin or from the same factory that Darwin's came from.