Chapter V: Appendix: I. Relations of Science and Religion 313 (3)

The outstanding general results of science as to the nature of energy are now before us. All observations concerning motion only present to view transmutations of energy, all of them imply that there is no such thing as the origin of energy, and no such thing as its extinction. There is indeed a constant tendency towards the degradation of energy, and a constant equalizing process which may bring to an end the present order of things in the universe. But the leading scientific conception with which we have specially to deal is that expressed in the phrase, "_Conservation of energy_," which must be regarded as completing our view of inorganic existence along with the other doctrine of the indestructibility of matter. As Professor Tait has expressed it,--"The grand principle of conservation of energy, which asserts that no portion of energy can be put out of existence, and no amount of energy can be brought into existence by any process at our command, is simply a statement of the invariability of the quantity of energy in the universe,--a companion statement to that of the invariability of the quantity of matter."[AJ]

The position is now reached at which it becomes possible to combine the results of scientific research as to matter and energy into a harmonious unity, with which to test the view of the world recognized by religious thought. Religion as an intelligent and devotional acknowledgment of a Supreme Being, involves a very clear and definite conception concerning the origin of the universe and its continuance. What is thus implied will be best indicated by negative as well as positive statements, in some such form as the following. First, _negatively_, the world we inhabit does not carry _within it_ any explanation of the origin of its own existence; that is to say, neither the materials existing, nor the forces operating, are sufficient to account for its origin; neither can it have had existence without beginning. In _positive_ form, the universe can be accounted for only by that which _transcends_ itself; the supernatural is the key to the natural; Nature is a creation to be attributed to an Intelligent First Cause.

Are science and religion here in harmony in the form and measure compatible in the circumstances? This qualified and guarded form of the question is obviously required, for religious thought does not profess to be scientific, or in any sense authoritative as to the phenomena of nature, that is, as to the facts which observation alone can ascertain, or as to the immediate causes by which these facts are to be explained. On the other hand, science is exclusively a knowledge of nature, consisting of methodized observations concerning distinct orders of facts, and rational inferences founded upon these. It can not in true sense be concerned with the supernatural, but can only present conclusions as to the order and processes of nature, which by subsequent and independent exercise of our intelligence may be contemplated in their relation to the conception of the supernatural, as Intelligent First Cause. This subsequent exercise of thought, whether critical or constructive, is more properly the task of philosophy, in prosecution of those reflective and speculative exercises, which, proceeding from scientific conclusions as accepted data, consider their intellectual value as contributing towards a theory of the universe. Scientific men will, of course, more or less readily pass over to take some share in such philosophic speculation; just as religious men, purely under the impulse of religious interests, will be more or less disposed to do, in proportion to the range of their intellectual life. What is here said is not intended as an argument for any restriction upon such speculation on the part either of scientific or of religious men, for such questions are common property, and the arguments bearing upon them are to be tested by all. But it is of some consequence, specially in the present unsettled and sensitive state of the public mind, that it be clearly recognized that science is not itself responsible for the thoughts of scientific men on these questions; and that religion is not responsible for the thoughts of religious men upon them. Science can not determine any thing as to a philosophy of the supernatural, any more than religion can determine any thing as to a science of nature. Whether we take the violent and even passionate antipathy to any acknowledgment of the supernatural which is found in the Essays of Clifford, or the profoundly reverential acknowledgment of the Deity in the writings and life of Faraday, science is to be credited with neither. And so in like manner, when we have violent denunciations of science professedly in the name of religion, or intelligent appreciation of its high value from accredited upholders of religious truth, religion itself is to be credited with neither the one nor the other. This is a matter which comes within the range of ordinary intelligence. It may indeed belong to philosophy to formulate and develop the arguments in strict harmony with the recognized laws of mind; but it belongs equally to all men to estimate the general sweep and range of acquired knowledge as to the structure and order of the universe, as bearing upon the more general conceptions to be rationally entertained regarding its government. With this branch of the subject, ordinary thought may readily deal without entanglement in technicalities.

There is as we have seen a _duality_ of existence in the inorganic structure of the world, and a continual succession of changes, on account of the interaction of these two. Different forms of matter stand in different relations; and these relations are being constantly interchanged by the transmutation of energy. Thus taking the world as presented to us, it has a constitution which requires for its explanation that we go beyond every thing to be found within itself. The matter in the universe can not account for the energy; nor can the energy account for the matter; and the relations between the two must find explanation in something higher than both. What their source may be, science is incapable of telling; it can not contribute towards satisfying the requirements of the law of causality in view of the mutual relations of matter and energy which it has itself revealed. But equally by what it has revealed, and by acknowledgment of its inability to transcend the limits of its own discoveries, does it present harmony with religious thought in the form and measure in which it is possible that such harmony could be manifested. Discovering the objective existence of matter and energy, and the laws in accordance with which the latter acts upon the former, it presents an unsolved problem affording the most direct and positive testimony possible to science in support of the existence of a First Cause, transcending the universe itself. How matter and energy came into being, it can not tell; but it most explicitly declares that by no power existing and operating within range of observation is it possible either to add to the sum of existence, or in the least degree to diminish it. Religious thought could expect nothing more direct and explicit in the form of scientific testimony as confirmation of its fundamental position. Scientific thought while dealing with inorganic existence could not, even by a single line of approach, be brought nearer to the actual support of religious belief.

Here the question may be raised,--May not the world have existed from eternity? In the answer to this question there are several considerations requiring to be distinguished. First, science has no testimony to offer, inasmuch as it does not get beyond the area of laws now operating. Second, the testimony of science concerning the world as now existing is inconsistent with the supposition of its eternal existence. The matter which is constantly operated upon by energy distinct from itself, does not possess the property of self-subsistence; neither does the energy which is constantly undergoing change. Continual transition or change from one phase of existence, or set of relations, to another, is a mark of the not-abiding, an evidence of subjection to, and dependence on, what is beyond and above itself. The non-enduring, or ever-changing, is constantly pointing to the ever-enduring.

Full understanding of the situation of things as discovered by science will produce a much deeper impression on the public mind than has yet been effected. The reasonableness of this expectation will readily appear, if only some few of the positions be placed conspicuously in view.

It is of special consequence to note that science has in this direction _finished its work_, and reached its _ultimatum_, in demonstrating the physical impossibility of either increasing or diminishing the existing sum total of matter, or of energy. The conclusions are not such as can be regarded as provisional, liable to be overreached, modified, or enlarged, by what may afterwards be discovered. We are so much influenced at present,--and scientific men share in the experience, as well as others,--by the general and well-grounded expectation of the unceasing advance of science, that it is peculiarly easy in sight of a great general problem such as the origin and government of the world, to overlook the significance of ultimate conclusions in given directions. In this way, we too readily fall into the delusive tendency of regarding accredited conclusions as still hanging in a measure of uncertainty, or at least as having a dubious future before them, because they border upon the region of the unknown so far as science is concerned, or upon a realm of mystery, which science regards either with aversion, or with cherished determination of attack. In the present singularly favorable position of science, it is impossible for the public mind to escape this tendency; but it becomes only the more imperative to distinguish as occasion offers, those conclusions which are to be taken as final. This is of immense consequence as bearing upon general conceptions concerning the universe.

That matter can not be originated, and can not by even a single atom be destroyed, is one of those ultimate statements, upon which physical science itself relies as on a foundation. This is a universally accredited truth, that "no portion of matter, however small, goes out of existence or comes into existence in any operation whatever."[AK] The wonderful chemical laboratory of living organism may change many forms of matter into living tissue, but all returns again to its place in the inorganic mass. Material may pass from one phase into another, but there is nothing more than change. The sum total of material existence is unaltered. To suggest the contrary,--and specially to do so in the name of science,--were to bring science face to face with the conceptions rejected as alien to its very nature; for to say that matter may be originated, is to affirm _creation_; to say that it may be destroyed, is to affirm the possibility of _annihilation_; and these two are beyond the range of science, and if once admitted within its boundaries, they would destroy science itself.

So it is when we pass over to the doctrine of energy. The same clear and ultimate conclusion is proclaimed. The doctrine of the conservation of energy is the _ultimatum_ on which physical science finds sure and firm foothold. In those two ultimate positions of scientific research concerning inorganic existence, religion finds support, and that of a kind so powerful, that science itself depends upon its immovability.

There is, however, a further point connected with the doctrine of energy, which deserves consideration as bearing on the tendency to anticipate an indefinite line of progression in the history of this world, that is, deterioration or degradation in the form of energy, while it continues of equal amount. The efficient value of energy is according to the possibilities of transformation or transmutation. But its use implies limitation of the available forms, or steady deterioration of value. "Thus the energy of the universe is, on the whole, constantly passing from higher to lower forms, and therefore the possibility of transformation is becoming smaller and smaller, so that after the lapse of sufficient time all higher forms of energy must have passed from the physical universe, and we can imagine nothing as remaining, except those lower forms which are incapable, so far as we yet know, of any further transformation."[AL] Such a statement of the position, though it can not be regarded as an ultimate one in scientific research, is so obviously a deduction from present knowledge that it must to some extent modify prevailing conceptions. It may, indeed be suggested that some catastrophe may terminate the present order of things, and that some action of the law of gravitation may combine the fragments of worlds, and give a fresh start with new combinations of energy; but the bare suggestion of this implies a much wider range for scientific research than any thing yet known to us, and at the same time a larger demand upon intelligence in the control and regulation of what must nevertheless seem to us violent catastrophes. Such speculation, if it may warrantably find encouragement under purely scientific conditions, religious thought will neither gainsay nor resist; but will find itself in no perplexity to accept.

Waiving, however, all speculation as to the possible future of the physical universe, we here concentrate attention on the past; we take the most recent scientific testimony as to the structure of the physical universe, as it bears on the problem concerning the origin of our world. Here the testimony of science is clearly and unmistakably in favor of the creation or absolute origin of matter and energy, in the only form in which science can bear any testimony on the subject. It is, of course, impossible that science should present direct testimony to the fact of creation, as it is impossible that history should; for such a fact as creation must be entirely beyond the range of science. But in testifying to the indestructibility and uncreatability of matter under the conditions capable of being investigated by observational science; and in bearing the same testimony as to the energy in the world, it offers all the support it is capable of offering to the reality of the supernatural,--testifying to the dependence of nature on some power altogether transcending itself. But here I prefer rather to use the words of a purely scientific observer. When dealing with the doctrine of energy, and specially with the consequences of dissipation of energy, Professor Tait uses these words,--"As it alone is able to lead us, by sure steps of deductive reasoning, to the necessary future of the universe--necessary, that is, if physical laws remain forever unchanged--so it enables us distinctly to say that the present order of things has _not_ been evolved through infinite past time by the agency of laws now at work; but must have had a distinctive beginning, a state beyond which we are totally unable to penetrate; a state, in fact, which must have been produced by other than the now visibly acting causes."[AM] This is the utmost that science can say, bearing on the great problem of the origin of the universe; and nothing more powerful could be said in direct testimony to the reality of the supernatural, and the reasonableness of Christian faith, thus shown to be in complete harmony with science.

It is not here suggested that all scientific men would employ such language as that now quoted, or even readily acquiesce in its use. I have been careful to indicate, that a passionately excited antagonism to any recognition of the supernatural is avowed by some scientific men. Accordingly, it must be granted that the conclusion here stated is not so manifest a deduction as to preclude denial. The testimony of the senses commonly terminates dispute, but such testimony is not available as to the reality of the supernatural. The only testimony that can be given here must be of a different kind; and if there be some who refuse to credit anything save what comes within range of the senses, or is deducible directly and simply from what the senses make known, there is no help for them. Neither science, nor philosophy, nor religion can deliver them from the narrow round of materialism. But neither science, nor philosophy, nor religion, can restrict itself to the testimony of the senses. A deeper, and wider range of inquiry is demanded of the man who would walk at large in the vast field spread out in nature. All human life is subjected to the test of accepting evidence other than that the senses supply. If some refuse to submit to this deeper and wider test, narrowing their convictions accordingly, others are not to be restricted in this way, nor are they to be influenced by such determination even on the part of highly distinguished scientific men. For, it can not be overlooked that this is not a question of science, nor does it imply any thing but an ordinary exercise of intelligence. The one test for the public mind is this,--Is it or is it not true that not an atom of matter can be originated or destroyed? Is the doctrine of the conservation of energy to be taken as scientifically demonstrated? These things science must decide, and beyond these, all is clear for ordinary intelligence. Of the testimony of science on these two questions there is no doubt whatever. Religion, therefore, has no conflict with science here; it simply accepts the teaching of science, finding in it ample support for its fundamental position. What creation really means, or how we can fittingly represent it to our minds, does not in the least affect the question here under discussion, for these are not points on which science can offer any testimony. Nor have the defenders of religion any complaint to urge against the claims which science makes to explain all that belongs to nature. But when those who make the largest claims for science, acknowledge that science is baffled here, their testimony gains in value by reason of the strength of their antipathy to the acknowledgment of the miraculous. When from an accredited scientific witness we have these words:--"The investigation of nature does not shrink from enrolling life and the processes of life in the world of the comprehensible," followed up by this explicit statement, "We are foiled only at the conception of matter and force";[AN] the claims of science are raised to the highest pitch; and yet its insuperable limits are clearly defined. The defender of the harmony of scientific with religious thought has nothing more to desire. The very place where science comes to a halt, acknowledging that its utmost boundary has been reached, is the place where it is demonstrated that scientific thought and religious are not involved in real conflict.

FOOTNOTES:

[AB] These allowances may well be made for Professor Clifford, one of the most extravagant assailants of religious faith.

[AC] Professor Tait in answer to Mr. Froude has advanced the evidence. _International Review_, Nov. 1878, vol. v. No. 6. The collected papers have been republished, _Atlas Series_, No. 11.

[AD] _Recent Advances in Physical Science_, by P. G. Tait, Professor of Natural Philosophy, University of Edinburgh, p. 17.

[AE] _Ib_. p. 2.

[AF] _Recent Advances in Physical Science_, p. 14.

[AG] See Appendix III.

[AH] _The Conservation of Energy_, by Balfour Stewart, p. 26.

[AI] _The Conservation of Energy_, p. 36.

[AJ] _Recent Advances of Physical Science_, p. 17.

[AK] Tait's _Recent Advances_, p. 15.

[AL] _Recent Advances_, p. 20.

[AM] _Recent Advances_, p. 22.

[AN] _The Doctrine of Descent_, by Oscar Schmidt, p. 20.

LECTURE IV.

ORGANIZED EXISTENCE: LIFE AND ITS DEVELOPMENT.--(DARWIN'S "THEORY OF EVOLUTION.")

In prosecuting our inquiry as to the most recent advances in science, we pass now from inorganic to organic existence; from the testimony of physicists, to that of zoölogists. This transition in itself starts a scientific problem, beyond which we are carried onward to a distinct and very complicated area of existence, higher in order, and pressing upon attention an incalculable variety of details, exceedingly difficult to harmonize. In the earlier stage of physical research, all observation and experiment lead forward to general results, which gain ready acceptance because they may be said to be involved in scientific procedure itself. In this more advanced stage it is otherwise. In the former, unorganized matter is the same everywhere; and the laws of energy can be studied with equal facility in Europe or in America, in northern latitudes or in southern. But when we begin to direct attention upon life in its manifold forms, as these are scattered all over the world, multitudes of distinct observations have to be prosecuted, and their results slowly accumulated, before even the most competent workers can occupy a position from which it is possible to make a beginning with our forecast of general conclusions. Even in the most favorable circumstances, a great deal must be left to problematic inference, and even to imagination. Gatherings of facts may be recorded in a manner which places them beyond reach of doubt, while theories founded upon them hang long in suspense, waiting confirmation on condition of being able to endure protracted criticism, and manifold applications. This accounts for the difficulty experienced in finding ready to hand general conclusions which have secured universal acceptance, when we begin to move somewhat freely over the wide regions presenting the manifold problems of organized existence. And as it is solely with general conclusions, that religious thought is concerned, some share of perplexity must attach to the attempt to discuss the question of harmony. We must here therefore be considerably involved in questions affecting theories which have gained wide favor in scientific circles, as well as with clearly recorded and certain results. Some general questions, such as that affecting the classification of animals, must be regarded as peculiarly scientific. Whether the classification of Linnæus, or of Cuvier, or some other more recently suggested, is to be preferred, is a matter which does not here concern us. But a theory of the origin of species must be considered, because it is not purely scientific, but brings science into direct relation with common thought as to the order of the universe, and may therefore stand related to religious thought.

Immediately on directing attention to organized existence,--to LIFE in any form,--we encounter a new problem, namely the relation of the organized to the unorganized. How is the appearance of this higher order of existence to be accounted for? Can we find in the nature of matter, and in the mechanical and chemical laws influencing its position and combination, any explanation of the appearance of life in the world? Or must we regard life as a new and higher fact, unexplained by reference to the lower form of existence, and incapable of explanation in this way? Whether there is a clear line of demarcation between vegetable and animal life is a comparatively subordinate question. It is the wider and more perplexing question which most fundamentally affects our general conceptions as to the history and government of the world? And when this question is pressed singly,--how can we account for the appearance of life in the world?--science has no answer to present. Life still remains a mystery in scientific times, as it had been in past ages. Much has been written as to the origin of species; nothing to any purpose has yet been said as to the origin of life itself. The secrets of the universe in this respect have eluded discovery, and a constrained silence is the consequence.

But if science itself has nothing to say as to this fundamental problem, scientific men have much to say as to the probability of a true solution of the mystery being forthcoming. There is in many quarters an expectation that we may yet understand the physical principles, that is, the mechanical and chemical combinations, which go to explain life as a working organism.[AO] The suggestions of Rumford and Joule may yet bear results in this direction, for it is matter of general agreement that living organism may be regarded as an engine doing a given amount of work, on condition of being supplied with a given amount of fuel in the form of nourishment. When therefore Rumford suggests that the animal is a more economical engine than any of the mechanical contrivances which man constructs, and when Joule advances considerably beyond this to suggest that the animal more resembles an electro-magnetic engine, than a heat engine, it seems quite within the range of possibility that in some such direction discovery may yet be made of the physical principles involved in life.

This, however, leaves untouched the deeper question as to the _origin of life_. We are entirely ignorant of any beginning of life which is not traced directly to a preceding living organism. Either, as in the case of plants, there is increase of life by fission, or separation from an earlier growth, or by means of seed grown upon the parent plant; or, as in the case of animals, by germ or ovum. But the question of the origin of life is remote from us historically, and perplexing to us experimentally. If we seek guidance historically, we turn to geology, and learn that the structure of the earth has involved successive formations. The materials of the earth's crust are not thrown together confusedly, but "exhibit a certain order of arrangement";[AP] the mineral masses are partly aqueous, partly igneous, in formation; according as they are one or other, they contain organic remains, or are marked by their absence. All that can be inferred from the data thus afforded is that at a certain period in the world's history, when temperature and other conditions affecting the possibility of organic existence were favorable, life appeared. As to the cause of its appearance, geology can give no testimony. If next, we refer to palæontology, we learn of the existence of colossal animals which have long since become extinct; but such researches only widen our acquaintance with different orders of animals, contributing nothing towards the solution of the problem concerning the origin of life. The experimental science of the present day, with all the advantages arising from microscopical observation, is altogether unable to offer any explanation. Experiments for the purpose of testing the probability of "spontaneous generation" have been already described, and their failure leaves experimental science without any direct testimony; while their history yields powerful indirect evidence in support of the position that origin of life apart from germ is unknown.

It is, however, desirable here, in order to give completeness to our view of the present situation, to remark that among scientific men there are some who have no expectation of a scientific explanation of the origin of life; while others are exceedingly hopeful that such explanation may be reached, in the latter class appearing naturally all those who openly proclaim against what they name an "incomprehensible act of creation," and voluntarily place themselves in antagonism to religious thought. It is, therefore, of some consequence to indicate the grounds on which such opposite views rest. On the one side, Professor Tait, while suggesting the possibility of yet discovering the physical principles which determine life, nevertheless adds, "Let no one imagine that, should we ever penetrate this mystery, we shall thereby be enabled to produce, except from life, even the lowest form of life."[AQ] On the other hand Professor Schmidt of Strasburg maintains the opposite view, affirming that "the investigation of nature does not shrink from enrolling _life_, and the processes of life in the world of the comprehensible."[AR] This latter assertion is not to be accounted for on the ground that Schmidt is the ardent admirer and defender of the theory of origin of species by natural selection, for it is clear, as he maintains in replying to Max Müller, that "the origin of life has in fact nothing to do with actual Darwinism, or natural selection, unless the principle of selection be extended to the inorganic world of matter."[AS] Mr. Darwin himself does not suggest any such extension, and his theory of species is not chargeable with it. It should, indeed, be clearly recognized on all hands that the naturalist confines himself to a narrower range of inquiry, taking existing phases of life as the subject of his study. Accordingly, whoever claims that the origin of life comes within the compass of science, does so on the ground that there is no demarcation between the organic and the inorganic,--that the former may arise directly from the latter,--and so he commits himself to a doctrine of descent world-wide in its application, involving development in the world of all its varied phases of existence from a mass of unorganized matter.

This explains the difference of opinion among scientific men as to the possibility of accounting for the origin of life. A certain number deny the possibility, as they do the possibility of explaining scientifically the origin of matter on the explicit ground indicated by Laplace,--"Present events are connected with the events of the past by a link resting on the obvious principle, that a thing can not begin to exist without a cause which produces it."[AT] They do not find in inorganic matter sufficient cause to account for life, and their expectations are restricted accordingly. Those who cherish a contrary expectation, do not vindicate it by contradiction of the obvious principle enunciated by Laplace, or even by maintaining that inorganic matter is adequate to produce living organism. They cling to the more general and doubtful position that no limits are to be assigned to science, or as it is often stated, all nature belongs to the comprehensible. The failure of past experiments is no proof that inevitable failure awaits other experiments which may yet be made. To abandon expectation seems to them to be unfaithful to science. In this fashion, Professor Schmidt declares that "to any one who holds open the possibility that, even now, animate may be evolved from inanimate, without the mediation of progenitors, _the first origin of life in this natural method is at once self-evident_."[AU] To this view the other side may legitimately reply, that if the origin of life be as easily accounted for, as provision is here made for the "self-evident," science will soon be at a discount. To those regarding the matter from without, and waiting for testimony as to what is scientifically established, it is clear that there is no explanation of the origin of life; and I think it will be most commonly held that the weight of reason as to expectations for the future lies with those who abandon the anticipation of any scientific explanation. There is, however, in actual conclusions on scientific evidence nothing involving conflict with religious conviction; and allowance will be made for continued and extended experiments, provided only that the "holding open the possibility," does not make the probability "self-evident."

Passing thus from the unsolved problem of the origin of life,--with the attendant acknowledgment that there is no scientific theory of the world's descent from primordial atoms, we advance to the testimony of science concerning different orders of life, and their relations to each other. Here there is no restriction as to the use of scientific methods; there is wide range for free action by the hosts of observers required for the work. A sense of the relief which this implies, in contrast with the hampering restraints surrounding the earlier question, imparts to the words of Schmidt a more jubilant tone, as he says, "Between beginning and end, we naturalists may do as we please."[AV]

In this region it will be universally admitted that the development of species by selection is the conception which has gained greatest hold upon the scientific mind within recent times. Accordingly it seems better to begin with an outline of this theory, and of its history as developed by Mr. Darwin, keeping, however, steadily in view the range of problem with which the theory has to deal.

As already remarked the origin of life is a problem quite distinct, and the theory of selection does not entangle itself by maintaining origin of life by development from unorganized matter. Mr. Darwin clearly guarded himself against responsibility for such a conception of its origin.[AW] Restricting thus far, we have to keep in view the vast range of the problem demanding scientific explanation.

Animal life manifests itself by spontaneous movement,--movement from within the living organism, in contrast with movement caused by energy applied from without. This holds true of every living germ, from which a mature animal form may be developed. This is the test of the presence of life under the microscope in minute germinal structures otherwise incapable of observation. In its lowest known form life appears in a minute vessel containing so much nourishment, which is within a nucleus or vital centre from which movement originates.[AX] This depends for its development on external conditions such as heat and moisture.[AY] Advance in the scale is connected with greater complexity in the organism. As we ascend, separate organs appear, fulfilling distinct functions, and controlled by means of a nerve system whose ramifications are according to the intricacy of the organism. The appearance of such a nerve system implies sensibility and motor activity, provision for an _experience_ more or less varied, and _movement_ in some measure according with it, or adapted to it. From a nerve system consisting of a centre and a few fibres, we gradually ascend, until in the higher vertebrate orders, we find a vast system of nerves harmonized and governed from a grand centre or terminus constituting the brain.[AZ] With the steadily advancing complexity of nerve system, there is great diversity in the orders of animals, in the variety of actions of which they are capable, in adaptation to different conditions of life, and in the modes in which they obtain subsistence. The scientific problem is--How far can we account for all this complex system of things by the action of natural causes?

As we are here specially concerned with ruling conceptions, and only indirectly with details, the relations of the animal and vegetable kingdoms may be passed, with the acknowledgment that the two are obviously distinct, and yet that the vegetable very nearly merges into the animal at certain points, as illustrated by sensibility, if not by locomotion. So may we waive discussion of the classification of animals, which involves important points closely connected with the main question. Allowing that the wonderful diversity in animal organization, may admit of different modes of classification; and yet granting that the structure of the animal economy in all its forms proceeds on common principles, which must lead to practical agreement as to modes of classification; we deal with the single question as to the natural causes serving to explain different orders.

Mr. Darwin's suggestion, largely supported by evidence from many quarters, and now commanding a very general support is, that all this diversity may be regarded as the product of a long process of development. This theory takes the whole orders of existence into one sweep. The lowest type of animal life presents to view the beginning of a protracted history; the highest order of animate existence indicates the stage of advance at which we observe things at the present period. For such a theory the history of individual development belonging to whatever order, and the history of distinct orders as indicating improvement and deviation of whatever aspect, present evidence of special value. The most important causes relied upon as contributing to the formation of a scientific theory may be presented under these four heads--(1) The action of external causes as provided for by environment; (2) power of adaptability within each organism, providing for changes according to requirement from without, which may be described as "adaptive changes of structure;" (3) "the struggle for existence," in accordance with which the strongest gain the mastery and consequent advantage in obtaining the means of subsistence; and (4) "natural selection" among the sexes, giving to the offspring all advantages according to the laws of hereditary descent.

The essential feature in this theory is the _power of adaptability inherent in the organism_. This is postulated as characteristic of all organized existence; and it is implied, that this power of adaptability multiplies in a degree approximating to the measure of complexity belonging to the organism. The inherent capacity for deviation is thus much less in the mollusk than in the bird; and in the bird much less than in the quadruped. Thus the development process which must, according to this view, have been exceedingly slow in the earlier stages, must have been greatly accelerated when more complex organisms had come into existence, and all the advantages accrued from greater diversity of materials. Such is a brief outline of the theory; and looked at simply as a theory, there is a manifest attraction in the boldness of the conception, and the wide sweep of the generalization which it includes. Taken merely as an intellectual representation setting forth a conceivable order of things in the universe, it has a great deal to command attention and awaken interest. It is, indeed, a novelty in the history of scientific thought, and as such at variance with previous conceptions, both scientific and non-scientific. But it is no more at variance with religious thought, than with ordinary notions of preceding times; while to the author whose name is now associated with it all over the scientific world, it is a more striking testimony of the marvels of creative power,[BA] than notions previously current, which regarded it as historically true that every existing variety of animal was launched into being by a distinct creative act. Whatever may be the ultimate view of the history of life on the earth, based on purely scientific data,--and we are still a far way removed from what may be regarded as scientific evidence for such a view,--the fewer the primordial forms to which the multiplicity of existing species can be traced, the greater is the marvel which science presents, and the more convincing becomes the intellectual necessity by which we travel back to a Supernatural Intelligence as the source of all. On the other hand, the slow process by which scientific research tends to make out the natural history of living organisms far removed from each other in the scale of being, tracing many groups to a common parentage, and assigning their appearance in the world to distinct periods in its history, will be seen to be so far anticipated and favored by the graphic description of the introduction of animal life given in the opening page of revelation, where different orders are assigned to successive epochs.

While, however, these things are said at the outset, as affording commencement for the study of an evolution theory, and delivering us from the supposition that there is an inevitable antagonism between science and recognition of the supernatural, we revert to the ruling principle for this whole inquiry, that science must prosecute its own researches, unfettered by forecast of consequences; and that the Bible is not to be handled as if it were a book of science, for it neither lays restraints upon human inquiry, nor delivers us from the need for it.

The best method for entering upon a study of the theory of evolution by natural selection is to take Mr. Darwin's own account of the manner in which it began to take shape before his mind. In his "historical sketch of the recent progress of opinion on the origin of species,"[BB] he traces to Lamark the first suggestions on the subject, directing public attention to the question in 1801; thereafter a succession of naturalists including St. Hilaire, Wells, and Patrick Matthew, from separate and incidental observations, dwelt upon the difficulty of distinguishing species, and on the evidence of an archetypal idea, or common plan of structure, being applicable in the history of whole orders. Mr. Darwin then gives the following biographical references at the outset,--"When on board H. M. S. 'Beagle,' as naturalist, I was much struck with certain facts in the distribution of the organic beings inhabiting South America, and in the geological relations of the present to the past inhabitants of that continent. These facts seemed to throw some light on the origin of species--that mystery of mysteries, as it has been called by one of our greatest philosophers. On my return home, it occurred to me in 1837, that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it. After five years' work I allowed myself to speculate on the subject, and drew up some short notes; these I enlarged in 1844 into a sketch of the conclusions which then seemed to me probable: from that period to the present day I have steadily pursued the same object."[BC] Such is Mr. Darwin's opening paragraph in the now celebrated _Origin of Species_. No one interested in such investigations will hesitate to approve and trust the "patiently accumulating and reflecting on all sorts of facts;" nor can there be any hesitation in granting the warrantableness of his beginning to speculate as to the probable results. On the other hand, even the most ardent admirers of the evolution theory can not refuse to allow that only its principles are certain, while its ultimate form is still matter of conjecture and speculation. Quite divergent lines of speculation have found a start within the compass of the phenomena brought under review, and it is already apparent that opposite tendencies of thought have effected a lodgment under the common name of evolution. In these circumstances there is no direct call, as there are no proper materials, for attempting a reconciliation between the principles of religion, and definite scientific conclusions as to the origin of species. We are still occupying that position which makes historical treatment of the subject the most appropriate, leaving to speculation the probable lines of adjustment which may render possible a wider induction bearing on a general theory of the universe.

The observations of Alfred Russell Wallace in the Malay Archipelago led towards the same conclusions as those indicated by Darwin, to whom Mr. Wallace dedicated his book,[BD] giving the results of research extending from 1854 to 1862, and in confirmation of Darwin's theory, though differing on important points, Wallace published in 1870 his _Contribution to the Theory of Natural Selection_. Mr. Darwin's views when first promulgated received decided though somewhat guarded support from Sir Charles Lyell, whose geological studies marked him out as a highly qualified witness on the subject, and were strongly favored by Dr. Hooker, author of _Introduction to the Australian Flora_, while they encountered not a little criticism, and were met with announcements of formal reservations, on the part of distinguished naturalists.

A fuller statement as to the history of his own thought was given by Mr. Darwin in the fifth edition of his work, and also in a letter to Hæckel, author of the bolder venture as to the _History of the Creation_, and the _Evolution of Man_. This letter to Hæckel may be given here as having considerable value in its bearing on the formation of the theory of evolution. After referring to his early researches as to lower forms of life, Mr. Darwin proceeds thus--"Having reflected much on the foregoing facts, it seemed to me probable that _allied species_ were descended from a common ancestor. But during several years I could not conceive how each form could have been modified so as to become admirably adapted to its place in nature. I began therefore to study domesticated animals and cultivated plants, and after a time perceived that _man's power of selecting and breeding_ from certain individuals was the most powerful of all means in the production of _new races_. Having attended to the habits of animals and their relations to the surrounding conditions, I was able to realize the severe _struggle for existence_ to which all organisms are subjected; and my geological observations had allowed me to appreciate to a certain extent the duration of past geological periods. With my mind thus prepared, I fortunately happened to read Malthus's _Essay on Population_; and the idea of natural selection through the struggle for existence at once occurred to me. Of all the subordinate points in the theory, the last which I understood was the cause of the _tendency_ in the descendants from a common progenitor _to diverge_ in character."[BE] This short passage in personal history may considerably aid others in their study of the theory.

This letter may with advantage be supplemented by one or two brief extracts from _The Origin of Species_. In one of his most recent editions, our author says,--"It may be metaphorically said, that natural selection is daily; and hourly scrutinizing throughout the world the slightest variations, rejecting those that are bad, preserving and adding up all that are good; silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life." Such a metaphorical representation attributing to nature different processes, such as scrutinizing, rejecting, preserving, and working, considerably aids us by pointing to the _intellectual_ conditions involved in the acceptance of the theory of evolution. To this it may suffice if there be added the closing passage in our author's work on species, indicating his view of the relation of all to the supernatural. It is in these words--"Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving,[BF] namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved."[BG] On this passage, Schmidt has remarked--"In this concession, Darwin has certainly been untrue to himself; and it satisfies neither those who believe in the continuous work of creation by a personal God, nor the partisans of natural evolution." In this criticism we have a good example of the manner in which an impression of conflict is fostered. The rejoinder to Schmidt is obvious. Those who value religion seek no concessions, but desire to banish from scientific and philosophic writing all thought tending in this direction. If, however, needless complications are to be avoided, we must have exact statements of the relative positions. The sentence just quoted involves a misrepresentation equally of religion and science. Belief in the supernatural does not imply belief in _a continuous work of creation_, and therefore does not carry any thing inherently antagonistic to the conception of evolution under natural law. On the other hand, belief in evolution of species under the action of natural law does not decide the question, concerning _the origin of life_, just as a science of nature can decide nothing concerning the supernatural.

Professor Schmidt is, however, so far from clearly and consistently recognizing the exact limit of the theory, that within the compass of a single page he first affirms the limitation, and then denies it. First vindicating Darwin from the attack of Max Müller as to beginning and end of living organism, he says, "The origin of life has in fact nothing to do with actual Darwinism, or natural selection, unless the principle of selection be extended to the inorganic world of matter,"[BH] an entanglement which Schmidt is willing to avoid, and which Darwin carefully shuns, distinctly stating that "Science in her present state does not countenance the belief that living creatures are now ever produced from inorganic matter."[BI] But Schmidt has no sooner placed himself behind this line of defence, than he attacks Darwin for acknowledging origin of life by creation, maintaining that "it is directly incompatible with the doctrine of descent."[BJ] The theorist must take either one side or the other. Either he must maintain that the theory of descent has "nothing to do with the origin of life," and in that case there is no conflict with religious thought; or that the theory of descent is incompatible with creation, and in that case there is conflict with religious thought, and at the same time inconsistency with science, in respect of its own definition as an explanation of nature, and in respect of its own results which do not involve "spontaneous generation," but do include the position that not a single particle of matter can be originated or destroyed by any power recognized in operation. No one will "dispute the claims of the investigation of nature to its logical inferences," but "where the material substratum is deficient," most reasonable men will demand that distinct acknowledgment be made of the fact, and that the boundaries of science be defined accordingly. If, however, any one be inclined to maintain that "where the material substratum is deficient," all inquiry must terminate, and human thought must refuse to go further, or to attempt to rise higher, this certainly is not science, but an illogical attempt to make the science of nature commensurate with the boundaries of thought,--an arbitrary declaration that "the causal series" within the material universe is the sum total of causality. Such an affirmation can not warrantably attach itself to a theory of descent, as it can not be tested by observational methods, but altogether by reference to the laws of thought determining the value of rationalizing processes. The theory of "natural evolution," implies evolution from something; it postulates a beginning from which it takes procedure, and it exhausts itself in observations concerning such deviations as occur in the annals of natural history. If, therefore, any of "the partisans of natural evolution," take up a position involving denial of a rational acknowledgment of the supernatural, they isolate themselves in so doing, leaving the theory free from responsibility as to their attitude, and taking upon themselves the logical necessity for vindicating their position on grounds with which the theory of evolution itself has no concern.

Having thus vindicated the theory of natural evolution from all share in the denial of creation, and having entered a protest upon purely scientific grounds against the attempt to translate a scientific theory concerning a limited order of facts within the universe into a metaphysical theory concerning the origin of the universe, we are in a position to concentrate upon the theory itself as an attempt to provide a scientific explanation of the history of living organism. And this is here done with the view of ascertaining, in a general and necessarily restricted manner, the value of the evidence presented for its acceptance, thereby ascertaining its relations to the essential characteristics of religious thought.

The first and simplest part of the task is to indicate the favorable impression it has made on the minds of men,--the conquest it has already won for itself,--as a theory carrying within it a large amount of truth, whatever may be its final form, after the very intricate and difficult questions involved have been carefully examined. The theory has carried general approval for the position that "allied species are descended from a common ancestor," or, stating the same view in the manner suggested by experiment, that it is possible to obtain in the history of a single race of animals, considerable deviations in structure, and to give these deviations fixedness or permanence by continuance of selected features along the line of hereditary descent. This has been amply illustrated by the examples of the various orders of pigeons, and of dogs; both classes of animals having been largely experimented upon, and the distinct varieties being easily recognized and popularly known. Comparatively little hesitation exists as to acknowledging that the different orders of pigeons have had a common ancestry; and that the same may be said of the different races of dogs. These examples afford the governing conception of the evolution theory, presenting the type of evidence which has led on to the wider generalization. Under the discussions which the theory has originated facts previously familiar have been contemplated in a different light, as bearing upon a general plan or order of procedure apparent in the history of organized existence. The consequent gain for the theory is altogether favorable to the restricted doctrine that allied species have had a common descent, or that a single type of organism may under the law of evolution lead to the appearance of different orders or races of animals.

The clear advance thus made in our conceptions of the history of the universe will appear by simple statement of negative results following from the admission of the modified form of doctrine just given. These involve the rejection of views previously held, not by religious men in religious interests, but by men generally, as the natural consequence of the want of scientific investigations fitted to guide the public mind. So far as a general conclusion has gained assent, men show no reluctance to accept the clear logical inferences following from the investigation of nature.