Darwiniana; Essays and Reviews Pertaining to Darwinism Part 11

decurrens, the incense cedar, is one of the n.o.blest a.s.sociates of the present redwoods. But all the rest are in the southern hemisphere, two at the southern extremity of the Andes, two in the South-Sea Islands. It is only by bold and far-reaching suppositions that they can be geographically a.s.sociated.

The genealogy of the Torreyas is still wholly obscure; yet it is not unlikely that the yew-like trees, named Taxites, which flourished with the Sequoias in the tertiary arctic forests, are the remote ancestors of the three species of Torreya, now severally in Florida, in California, and in j.a.pan.

As to the pines and firs, these were more numerously a.s.sociated with the ancient Sequoias of the polar forests than with their present representatives, but in different species, apparently more like those of Eastern than of Western North America. They must have encircled the polar zone then, as they encircle the present temperate zone now.

I must refrain from all enumeration of the angiospermous or ordinary deciduous trees and shrubs, which are now known, by their fossil remains, to have flourished throughout the polar regions when Greenland better deserved its name and enjoyed the present climate of New England and New Jersey. Then Greenland and the rest of the north abounded with oaks, representing the several groups of species which now inhabit both our Eastern and Western forest districts; several poplars, one very like our balsam poplar or balm-of-Gilead tree; more beeches than there are now, a hornbeam, and a hop-hornbeam, some birches, a persimmon, and a planer-tree, near representatives of those of the Old World, at least of Asia, as well as of Atlantic North America, but all wanting in California; one Juglans like the walnut of the Old World, and another like our black walnut; two or three grapevines, one near our Southern fox grape or muscadine, another near our Northern frostgrape; a Tilia, very like our ba.s.swood of the Atlantic States only; a Liquidambar; a magnolia, which recalls our M.

grandiflora; a Liriodendron, sole representative of our tulip-tree; and a sa.s.safras, very like the living tree.

Most of these, it will be noticed, have their nearest or their only living representatives in the Atlantic States, and when elsewhere, mainly in Eastern Asia. Several of them, or of species like them, have been detected in our tertiary deposits, west of the Mississippi, by Newberry and Lesquereux. Herbaceous plants, as it happens, are rarely preserved in a fossil state, else they would probably supply additional testimony to the antiquity of our existing vegetation, its wide diffusion over the northern and now frigid zone, and its enforced migration under changes of climate.[V-7] Concluding, then, as we must, that our existing vegetation is a continuation of that of the tertiary period, may we suppose that it absolutely originated then? Evidently not. The preceding Cretaceous period has furnished to Carruthers in Europe a fossil fruit like that of the Sequoia gigantea of the famous groves, a.s.sociated with pines of the same character as those that accompany the present tree; has furnished to Heer, from Greenland, two more Sequoias, one of them identical with a tertiary species, and one nearly allied to Sequoia Langsdorfii, which in turn is a probable ancestor of the common California redwood; has furnished to Newberry and Lesquereux in North America the remains of another ancient Sequoia, a Glyptostrobus, a Liquidambar which well represents our sweet-gum-tree, oaks a.n.a.logous to living ones, leaves of a plane-tree, which are also in the Tertiary, and are scarcely distinguishable from our own Plata.n.u.s occidentalis, of a magnolia and a tulip-tree, and "of a sa.s.safras undistinguishable from our living species." I need not continue the enumeration. Suffice it to say that the facts justify the conclusion which Lesquereux--a scrupulous investigator--has already announced: that "the essential types of our actual flora are marked in the Cretaceous period, and have come to us after pa.s.sing, without notable changes, through the Tertiary formations of our continent."

According to these views, as regards plants at least, the adaptation to successive times and changed conditions has been maintained, not by absolute renewals, but by gradual modifications. I, for one, cannot doubt that the present existing species are the lineal successors of those that garnished the earth in the old time before them, and that they were as well adapted to their surroundings then, as those which flourish and bloom around us are to their conditions now. Order and exquisite adaptation did not wait for man's coming, nor were they ever stereotyped. Organic Nature--by which I mean the system and totality of living things, and their adaptation to each other and to the world--with all its apparent and indeed real stability, should be likened, not to the ocean, which varies only by tidal oscillations from a fixed level to which it is always returning, but rather to a river, so vast that we can neither discern its sh.o.r.es nor reach its sources, whose onward flow is not less actual because too slow to be observed by the ephemerae which hover over its surface, or are borne upon its bosom.

Such ideas as these, though still repugnant to some, and not long since to many, have so possessed the minds of the naturalists of the present day that hardly a discourse can be p.r.o.nounced or an investigation prosecuted without reference to them. I suppose that the views here taken are little, if at all, in advance of the average scientific mind of the day. I cannot regard them as less n.o.ble than those which they are succeeding. An able philosophical writer, Miss Frances Power Cobbe, has recently and truthfully said:[V-8]

"It is a singular fact that, when we can find out how anything is done, our first conclusion seems to be that G.o.d did not do it. No matter how wonderful, how beautiful, how intimately complex and delicate has been the machinery which has worked, perhaps for centuries, perhaps for millions of ages, to bring about some beneficent result, if we can but catch a glimpse of the wheels its divine character disappears."

I agree with the writer that this first conclusion is premature and unworthy--I will add, deplorable. Through what faults or infirmities of dogmatism on the one hand, and skepticism on the other, it came to be so thought, we need not here consider. Let us hope, and I confidently expect, that it is not to last; that the religious faith which survived without a shock the notion of the fixity of the earth itself may equally outlast the notion of the fixity of the species which inhabit it; that, in the future even more than in the past, faith in an order, which is the basis of science, will not--as it cannot reasonably--be dissevered from faith in an Ordainer, which is the basis of religion.

VI

THE ATt.i.tUDE OF

WORKING NATURALISTS

TOWARD DARWINISM [VI-1]

(The Nation, October 16, 1873)

That homely adage, "What is one man's meat is another man's poison," comes to mind when we consider with what different eyes different naturalists look upon the hypothesis of the derivative origin of actual specific forms, since Mr. Darwin gave it vogue and vigor and a raison d'etre for the present day. This latter he did, not only by bringing forward a vera causa in the survival of the fittest under changing circ.u.mstances--about which the question among naturalists mainly is how much it will explain, some allowing it a restricted, others an unlimited operation--but also by showing that the theory may be made to do work, may shape and direct investigations, the results of which must in time tell us whether the theory is likely to hold good or not. If the hypothesis of natural selection and the things thereto appertaining had not been capable of being put to useful work, although, like the "Vestiges of the Natural History of Creation," it might have made no little noise in the world, it would hardly have engaged the attention of working naturalists as it has done. We have no idea even of opening the question as to what work the Darwinian theory has incited, and in what way the work done has reacted upon the theory; and least of all do we like to meddle with the polemical literature of the subject, already so voluminous that the German bibliographers and booksellers make a separate cla.s.s of it. But two or three treatises before us, of a minor or incidental sort, suggest a remark or two upon the att.i.tude of mind toward evolutionary theories taken by some of the working naturalists.

Mr. Darwin's own expectation, that his new presentation of the subject would have little or no effect upon those who had already reached middle-age, has--out of Paris--not been fulfilled. There are, indeed, one or two who have thought it their duty to denounce the theory as morally dangerous, as well as scientifically baseless; a recent instance of the sort we may have to consider further on. Others, like the youth at the river's bank, have been waiting in confident expectation of seeing the current run itself dry. On the other hand, a notable proportion of the more active-minded naturalists had already come to doubt the received doctrine of the entire fixity of species, and still more that of their independent and supernatural origination. While their systematic work all proceeded implicitly upon the hypothesis of the independence and entire permanence of species, they were perceiving more or less clearly that the whole question was inevitably to be mooted again, and so were prepared to give the alternative hypothesis a dispa.s.sionate consideration. The veteran Lyell set an early example, and, on a reconsideration of the whole question, wrote anew his famous chapter and reversed his former and weighty opinion. Owen, still earlier, signified his adhesion to the doctrine of derivation in some form, but apparently upon general, speculative grounds; for he repudiated natural selection, and offered no other natural solution of the mystery of the orderly incoming of cognate forms. As examples of the effect of Darwin's "Origin of Species" upon the minds of naturalists who are no longer young, and whose prepossessions, even more than Lyell's, were likely to bias them against the new doctrine, two from the botanical side are brought to our notice through recent miscellaneous writings which are now before us.[VI-2]

Before the publication of Darwin's first volume, M. Alphonse de Candolle had summed up the result of his studies in this regard, in the final chapter of his cla.s.sical "Geographie Botanique Raisonnee," in the conclusion, that existing vegetation must be regarded as the continuation, through many geological and geographical changes, of the anterior vegetations of the world; and that, consequently, the present distribution of species is explicable only in the light of their geological history. He surmised that, notwithstanding the general stability of forms, certain species or quasi-species might have originated through diversification under geographical isolation. But, on the other hand, he was still disposed to admit that even the same species might have originated independently in two or more different regions of the world; and he declined, as unpractical and unavailing, all attempts to apply hypotheses to the elucidation of the origin of species. Soon after Darwin's book appeared, De Candolle had occasion to study systematically a large and wide-spread genus-- that of the oak. Investigating it under the new light of natural selection, he came to the conclusion that the existing oaks are all descendants of earlier forms, and that no clear line can be drawn between the diversification whic h has resulted in species and that which is exhibited in races and minor varieties.

And now, in the introductory chapter of the volume of essays before us, he informs us that the idea which pervades them all, and in some sort connects very diverse topics, is that of considering this principle of selection. Of the principle itself, he remarks that it is neither a theory nor an hypothesis, but the expression of a necessary fact; that to deny it is very much like denying that round stones will roll downhill faster and farther than flat ones; and that the question of the present day in natural history is not whether there be natural selection, or even whether forms are derived from other forms, but to comprehend how, in what proportions, and by what means hereditary deviations take place, and in what ways an inevitable selection takes effect upon these. In two of these essays natural selection is directly discussed in its application to the human race; the larger one dealing ably with the whole subject, and with results at first view seemingly in a great degree negative, but yet showing that the supposed "failure of natural selection in the case of man" was an unwarrantable conclusion from too limited a view of a very complicated question. The article abounds in acute and fertile suggestions, and its closing chapter, "on the probable future of the human species" under the laws of selection, is highly interesting and noteworthy. The other and shorter essay discusses a special point, and brings out a corollary of the law of heredity which may not have been thought of before, but which is perfectly clear as soon as it is stated. It explains at once why contagious or epidemic diseases are most fatal at their first appearance, and less so afterward: not by the dying out of a virus--for, when the disease reaches a new population, it is as virulent as ever (as, for instance, the smallpox among the Indians)--but by the selection of a race less subject to attack through the destruction of those that were more so, and the inheritance of the comparative immunity by the children and the grandchildren of the survivors; and how this immunity itself, causing the particular disease to become rare, paves the way to a return of the original fatality; for the ma.s.s of such population, both in the present and the immediately preceding generation, not having been exposed to the infection, or but little exposed, has not undergone selection, and so in time the proportion liable to attack, or to fatal attack, gets to be as large as ever. The greater the fatality, especially in the population under marriageable age, the more favorable the condition of the survivors; and, by the law of heredity, their children should share in the immunity. This explanation of the cause, or of one cause, of the return of pests at intervals no less applies to the diminution of the efficacy of remedies, and of preventive means, such as vaccination. When Jenner introduced vaccination, the small-pox in Europe and European colonies must have lost somewhat of its primitive intensity by the vigorous weeding out of the more susceptible through many generations. Upon the residue, vaccination was almost complete protection, and, being generally practised, small-pox consequently became rare. Selection thus ceasing to operate, a population arises which has not been exposed to the contagion, and of which a considerable proportion, under the common law of atavism, comes to be very much in the condition of a people invaded for the first time by the disease. To these, as we might expect, vaccination would prove a less safeguard than to their progenitors three or four generations before.

Mr. Bentham is a veteran systematic botanist of the highest rank and widest knowledge. He had not, so far as we know, touched upon questions of origination in the ante-Darwinian era. The dozen of presidential addresses delivered at anniversary meetings of the Linnean Society, from his a.s.sumption of the chair in the year 1862 down to the current year--each devoted to some topic of interest--and his recent "Memoir on Compositae,"

summing up the general results of a revision of an order to which a full tenth of all higher plants belong, furnish apt examples both of cautious criticism, conditional a.s.sent (as becomes the inaugurator of the quantification of the predicate), and of fruitful application of the new views to various problems concerning the cla.s.sification and geographical distribution of plants. In his hands the hypothesis is turned at once to practical use as an instrument of investigation, as a means of interrogating Nature. In the result, no doubt seems to be left upon the author's mind that the existing species of plants are the result of the differentiation of previous species, or at least that the derivative hypothesis is to be adopted as that which offers the most natural, if not the only, explanation of the problems concerned. Similar conclusions reached in this country, from a study of the relations of its present flora with that which in earlier ages occupied the arctic zone, might also be referred to. (See preceding article.)

An excellent instance of the way in which the derivative hypothesis is practically applied in these days, by a zoologist, is before us in Prof.

Flower's modest and admirable paper on the Ungulata, or hoofed animals, and their geological history. We refer to it here, not so much for the conclusions it reaches or suggests, as to commend the clearness and the impartiality of the handling, and the sobriety and moderation of the deductions. Confining himself "within the region of the known, it is shown that, at least in one group of animals, the facts which we have as yet acquired point to the former existence of various intermediate forms, so numerous that they go far to discredit the view of the sudden introduction of new species. . . . The modern forms are placed along lines which converge toward a common centre." The gaps between the existing forms of the odd-toed group of ungulates (of which horses, rhinoceroses, and tapirs, are the princ.i.p.al representatives) are most bridged over by palaeontology, and somewhat the same may be said of the even-toed group, to which the ruminants and the porcine genus belong. "Moreover, the lines of both groups to a certain extent approximate, but, within the limits of our knowledge, they do not meet. . - . Was the order according to which the introduction of new forms seems to have taken place since the Eocene then entirely changed, or did it continue as far back as the period when these lines would have been gradually fused in a common centre?"

Facts like these, which suggest grave diversification under long lapse of time, are well supplemented by those which essentially demonstrate a slighter diversification of many species over a wide range of s.p.a.ce; whether into species or races depends partly upon how the naturalist uses these terms, partly upon the extent of the observations, or luck in getting together intermediate forms. The researches of Prof. Baird upon the birds of this continent afford a good ill.u.s.tration. A great number of our birds which have been, and must needs have been, regarded as very distinct species, each mainly with its own geographical area, are found to mingle their characters along bordering lines; and the same kinds of differences (of coloration, form, or other) are found to prevail through the species of each region, thus impressing upon them a geographical facies. Upon a submergence of the continent, reducing these several regions to islands sufficiently separated, these forms would be unquestioned species.

Considerations such as these, of which a few specimens have now been adduced (not general speculations, as the unscientific are apt to suppose), and trials of the new views to see how far they will explain the problems or collocate the facts they are severally dealing with, are what have mainly influenced working naturalists in the direction of the provisional acceptance of the derivative hypothesis. They leave to polemical speculators the fruitless discussion of the question whether all species came from one or two, or more; they are trying to grasp the thing by the near, not by the farther end, and to ascertain, first of all, whether it is probable or provable that present species are descendants of former ones which were like them, but less and less like them the farther back we go.

And it is worth noting that they all seem to be utterly unconscious of wrong-doing. Their repugnance to novel hypotheses is only the natural and healthy one. A change of a wonted line of thought is not made without an effort, nor need be made without adequate occasion. Some courage was required of the man who first swallowed an oyster from its sh.e.l.l; and of most of us the snail would still demand more. As the unaccustomed food proves to be good and satisfying, and also harmless, we may come to like it. That, however, which many good and eminent naturalists find to be healthful and reasonable, and others innocuous, a few still regard as most unreasonable and harmful. At present, we call to mind only two who not only hold to the entire fixity of species as an axiom or a confirmed principle, but also as a dogma, and who maintain, either expressly or implicitly, that the logical ant.i.thesis to the creation of species as they are, is not by law (which implies intention), but by chance. A recent book by one of these naturalists, or rather, by a geologist of eminence, the "Story of the Earth and Man," by Dr. Dawson,4 is now before us. The t.i.tle is too near that of Guyot's "Earth and Man," with the publication of which popular volume that distinguished physical naturalist commenced his career in this country; and such catch-t.i.tles are a sort of trade-mark. As to the nature and merits of Dr. Dawson's work, we have left ourselves s.p.a.ce only to say: 1. That it is addressed ad populum, which renders it rather the more than less amenable to the criticisms we may be disposed to make upon it. 2. That the author is thoroughly convinced that no species or form deserving the name was ever derived from another, or originated from natural causes; and he maintains this doctrine with earnestness, much variety of argument and ill.u.s.tration, and no small ability; so that he may be taken as a representative of the view exactly opposed to that which is favored by those naturalists whose essays we have been considering--to whom, indeed, he stands in marked contrast in spirit and method, being greatly disposed to argue the question from the remote rather than the near end. 3. And finally, he has a conviction that the evolutionary doctrines of the day are not only untrue, but thoroughly bad and irreligious. This belief, and the natural anxiety with which he contemplates their prevalence, may excuse a certain vehemence and looseness of statement which were better avoided, as where the geologists of the day are said to be "broken up into bands of specialists, little better than scientific banditti, liable to be beaten in detail, and p.r.o.ne to commit outrages on common-sense and good taste which bring their otherwise good cause into disrepute;" and where he despairingly suggests that the prevalence of the doctrines he deprecates "seems to indicate that the acc.u.mulated facts of our age have gone altogether beyond its capacity for generalization, and, but for the vigor which one sees everywhere, might be taken as an indication that the human mind has fallen into a state of senility."

This is droll reading, when one considers that the "evolutionist" is the only sort of naturalist who has much occasion to employ his "capacity for generalization" upon "the acc.u.mulated facts" in their bearing upon the problem of the origin of species; since the "special creationist," who maintains that they were supernaturally originated just as they are, by the very terms of his doctrine places them out of the reach of scientific explanation. Again, when one reflects upon the new impetus which the derivative hypothesis has given to systematic natural history, and reads the declaration of a master in this department (the President of the Linnean Society) that Mr. Darwin "has in this nineteenth century brought about as great a revolution in the philosophic study of organic Nature as that which was effected in the previous century by the immortal Swede," it sounds oddly to hear from Dr. Dawson that "it obliterates the fine perception of differences from the mind of the naturalist, . . . . destroys the possibility of a philosophical cla.s.sification, reducing all things to a mere series, and leads to a rapid decay in systematic zoology and botany, which is already very manifest among the disciples of Spencer and Darwin in England." So, also, "it removes from the study of Nature the ideas of final cause and purpose"--a sentence which reads curiously in the light of Darwin's special investigations, such as those upon the climbing of plants, the agency of insects in the fertilization of blossoms, and the like, which have brought back teleology to natural science, wedded to morphology and already fruitful of discoveries. The difficulty with Dr. Dawson here is (and it need not be underrated) that apparently he cannot as yet believe an adaptation, act, or result, to be purposed the apparatus of which is perfected or evolved in the course of Nature--a common but a crude state of mind on the part of those who believe that there is any originating purpose in the universe, and one which, we are sure, Dr. Dawson does not share as respects the material world until he reaches the organic kingdoms, and there, possibly, because he sees man at the head of them--of them, while above them. However that may be, the position which Dr. Dawson chooses to occupy is not left uncertain. After concluding, substantially, that those "evolutionists" who exclude design from Nature thereby exclude theism, which n.o.body will deny, he proceeds (on page 348) to give his opinion that the "evolutionism which professes to have a creator somewhere behind it . . . .

is practically atheistic," and, "if possible, more unphilosophical than that which professes to set out from absolute and eternal nonent.i.ty," etc.

There are some sentences which might lead one to suppose that Dr. Dawson himself admitted of an evolution "with a creator somewhere behind it." He offers it (page 320) as a permissible alternative that even man "has been created mediately by the operation of forces also concerned in the production of other animals;" concedes that a just theory "does not even exclude evolution or derivation, to a certain extent" (page 341); and that "a modern man of science" may safely hold "that all things have been produced by the Supreme Creative Will, acting either directly or through the agency of the forces and materials of his own production." Well, if this be so, why denounce the modern man of science so severely upon the other page merely for accepting the permission? At first sight, it might be thought that our author is exposing himself in one paragraph to a share of the condemnation which he deals out in the other. But the permitted views are nowhere adopted as his own; the evolution is elsewhere restricted within specific limits; and as to "mediate creation," although we cannot divine what is here meant by the term, there is reason to think it does not imply that the several species of a genus were mediately created, in a natural way, through the supernatural creation of a remote common ancestor.

So that his own judgment in the matter is probably more correctly gathered from the extract above referred to and other similar deliverances, such as that in which he warns those who "endeavor to steer a middle course, and to maintain that the Creator has proceeded by way of evolution," that "the bare, hard logic of Spencer, the greatest English authority on evolution, leaves no place for this compromise, and shows that the theory, carried out to its legitimate consequences, excludes the knowledge of a Creator and the possibility of his work."

Now, this is a dangerous line to take. Those defenders of the faith are more zealous than wise who must needs fire away in their catapults the very bastions of the citadel, in the defense of outposts that have become untenable. It has been and always will be possible to take an atheistic view of Nature, but far more reasonable from science and philosophy only to take a theistic view. Voltaire's saying here holds true: that if there were no G.o.d known, it would be necessary to invent one. It is the best, if not the only, hypothesis for the explanation of the facts. Whether the philosophy of Herbert Spencer (which is not to our liking) is here fairly presented, we have little occasion and no time to consider. In this regard, the close of his article No. 12 in the Contemporary Review shows, at least, his expectation of the entire permanence of our ideas of cause, origin, and religion, and predicts the futility of the expectation that the "religion of humanity" will be the religion of the future, or "can ever more than temporarily shut out the thought of a Power, of which humanity is but a small and fugitive product, which was in its course of ever-changing manifestation before humanity was, and will continue through other manifestations when humanity has ceased to be." If, on the one hand, the philosophy of the unknowable of the Infinite may be held in a merely quasi-theistic or even atheistic way, were not its ablest expounders and defenders Hamilton and Dean Mansel? One would sup-pose that Dr. Dawson might discern at least as much of a divine foundation to Nature as Herbert Spencer and Matthew Arnold; might recognize in this power that "something not ourselves that makes" for order as well as "for righteousness," and which he fitly terms supreme creative will; and, resting in this, endure with more complacency and faith the inevitable prevalence of evolutionary views which he is powerless to hinder. Although he cannot arrest the stream, he might do something toward keeping it in safe channels.

We wished to say something about the way in which scientific men, worthy of the name, hold hypotheses and theories, using them for the purpose of investigation and the collocation of facts, yielding or withholding a.s.sent in degrees or provisionally, according to the amount of verification or likelihood, or holding it long in suspense; which is quite in contrast to that of amateurs and general speculators (not that we reckon Dr. Dawson in this cla.s.s), whose a.s.sent or denial seldom waits, or endures qualification.

With them it must on all occasions be yea or nay only, according to the letter of the Scriptural injunction, and whatsoever is less than this, or between the two, cometh of evil.

VII

EVOLUTION AND

THEOLOGY [VII-1]

(The Nation, January 15, 1874)

The att.i.tude of theologians toward doctrines of evolution, from the nebular hypothesis down to "Darwinism," is no less worthy of consideration, and hardly less diverse, than that of naturalists. But the topic, if pursued far, leads to questions too wide and deep for our handling here, except incidentally, in the brief notice which it falls in our way to take of the Rev. George Henslow's recent volume on "The Theory of Evolution of Living Things." This treatise is on the side of evolution, "considered as ill.u.s.trative of the wisdom and beneficence of the Almighty." It was submitted for and received one of the Actonian prizes recently awarded by the Royal Inst.i.tution of Great Britain. We gather that the staple of a part of it is worked up anew from some earlier discourses of the author upon "Genesis and Geology," "Science and Scripture not antagonistic," etc.

In coupling with it a chapter of the second volume of Dr. Hodge's "Systematic Theology (Part II, Anthropology)," we call attention to a recent essay, by an able and veteran writer, on the other side of the question. As the two fairly enough represent the extremes of Christian thought upon the subject, it is convenient to review them in connection.

Theologians have a short and easy, if not wholly satisfactory, way of refuting scientific doctrines which they object to, by pitting the authority or opinion of one savant against another. Already, amid the currents and eddies of modern opinion, the savants may enjoy the same advantage at the expense of the divines-- we mean, of course, on the scientific arena; for the mutual refutation of conflicting theologians on their own ground is no novelty. It is not by way of offset, however, that these divergent or contradictory views are here referred to, but only as an ill.u.s.tration of the fact that the divines are by no means all arrayed upon one side of the question in hand. And indeed, in the present transition period, until some one goes much deeper into the heart of the subject, as respects the relations of modern science to the foundations of religious belief, than either of these writers has done, it is as well that the weight of opinion should be distributed, even if only according to prepossessions, rather than that the whole stress should bear upon a single point, and that perhaps the authority of an interpretation of Scripture. A consensus of opinion upon Dr. Hodge's ground, for instance (although better guarded than that of Dr.

Dawson), if it were still possible, would--to say the least--probably not at all help to reconcile science and religion. Therefore, it is not to be regretted that the diversities of view among accredited theologians and theological naturalists are about as wide and as equably distributed between the extremes (and we may add that the views themselves are quite as hypothetical) as those which prevail among the various naturalists and natural philosophers of the day.

As a theologian, Mr. Henslow doubtless is not to be compared with the veteran professor at Princeton. On the other hand, he has the advantage of being a naturalist, and the son of a naturalist, as well as a clergyman: consequently he feels the full force of an array of facts in nature, and of the natural inferences from them, which the theological professor, from his Biblical standpoint, and on his implicit a.s.sumption that the Old Testament must needs teach true science, can hardly be expected to appreciate.

Accordingly, a naturalist would be apt to say of Dr. Hodge's exposition of "theories of the universe" and kindred topics--and in no captious spirit-- that whether right or wrong on particular points, he is not often right or wrong in the way of a man of science.

Probably from the lack of familiarity with prevalent ideas and their history, the theologians are apt to suppose that scientific men of the present day are taking up theories of evolution in pure wantonness or mere superfluity of naughtiness; that it would have been quite possible, as well as more proper, to leave all such matters alone. Quieta non movere is doubtless a wise rule upon such subjects, so long as it is fairly applicable. But the time for its application in respect to questions of the origin and relations of existing species has gone by. To ignore them is to imitate the foolish bird that seeks security by hiding its head in the sand. Moreover, the naturalists did not force these questions upon the world; but the world they study forced them upon the naturalists. How these questions of derivation came naturally and inevitably to be revived, how the c.u.mulative probability that the existing are derived from preexisting forms impressed itself upon the minds of many naturalists and thinkers, Mr.

Henslow has briefly explained in the introduction and ill.u.s.trated in the succeeding chapters of the first part of his book. Science, he declares, has been compelled to take up the hypothesis of the evolution of living things as better explaining all the phenomena. In his opinion, it has become "infinitely more probable that all living and extinct beings have been developed or evolved by natural laws of generation from preexisting forms, than that they, with all their innumerable races and varieties, should owe their existences severally to Creative fiats." This doctrine, which even Dr. Hodge allows may possibly be held in a theistic sense, and which, as we suppose, is so held or viewed by a great proportion of the naturalists of our day, Mr. Henslow maintains is fully compatible with dogmatic as well as natural theology; that it explains moral anomalies, and accounts for the mixture of good and evil in the world, as well as for the merely relative perfection of things; and, finally, that "the whole scheme which G.o.d has framed for man's existence, from the first that was created to all eternity, collapses if the great law of evolution be suppressed."

The second part of his book is occupied with a development of this line of argument. By this doctrine of evolution he does not mean the Darwinian hypothesis, although he accepts and includes this, looking upon natural selection as playing an important though not an unlimited part. He would be an evolutionist with Mivart and Owen and Argyll, even if he had not the vera causa which Darwin contributed to help him on. And, on rising to man, he takes ground with Wallace, saying:

"I would wish to state distinctly that I do not at present see any evidence for believing in a gradual development of man from the lower animals by ordinary natural laws; that is, without some special interference, or, if it be preferred, some exceptional conditions which have thereby separated him from all other creatures, and placed him decidedly in advance of them all. On the other hand, it would be absurd to regard him as totally severed from them. It is the great degree of difference I would insist upon, bodily, mental, and spiritual, which precludes the idea of his having been evolved by exactly the same processes, and with the same limitations, as, for example, the horse from the palaeotherium."

In ill.u.s.trating this view, he reproduces Wallace's well-known points, and adds one or two of his own. We need not follow up his lines of argument.

The essay, indeed, adds nothing material to the discussion of evolution, although it states one side of the case moderately well, as far as it goes.

Dr. Hodge approaches the subject from the side of systematic theology, and considers it mainly in its bearing upon the origin and original state of man. Under each head he first lays down "the Scriptural doctrine," and then discusses "anti-Scriptural theories," which latter, under the first head, are the heathen doctrine of spontaneous generation, the modern doctrine of spontaneous generation, theories of development, specially that of Darwin, the atheistic character of the theory, etc. Although he admits "that there is a theistic and an atheistic form of the nebular hypothesis as to the origin of the universe, so there may be a theistic interpretation of the Darwinian theory," yet he contends that "the system is thoroughly atheistic," notwithstanding that the author "expressly acknowledges the existence of G.o.d." Curiously enough, the atheistic form of evolutionary hypotheses, or what he takes for such, is the only one which Dr. Hodge cares to examine. Even the "Reign of Law" theory, Owen's "purposive route of development and chance . . . . by virtue of inherent tendencies thereto," as well as other expositions of the general doctrine on a theistic basis, are barely mentioned without a word of comment, except, perhaps, a general "protest against the arraying of probabilities against the teachings of Scripture."