THE DOCTRINE OF EVOLUTION.
THE editor of Scribner's Magazine, in a leading article in the October number, attempts to bring THE POPULAR SCIENCE MONTHLY into reproach for its obnoxious opinions. There is a certain doctrine lately much talked about that is known to be odious among a great number of magazine-buying people. It is charged (on what authority is not stated) that the editor of THE POPULAR SCIENCE MONTHLY is an irrepressible partisan of this doctrine, and that, having made certain specious promises to its readers to furnish them with good, sound, scientific reading, he has betrayed their confidence by setting his pages ablaze with expositions of this doctrine, that so many people are known to regard with detestation. The little game here undertaken is old, and has been often played with success; but, with the growth of intelligence and liberality, it is getting disreputable, and our neighbor is welcome to all he can make by it. It is customary in such cases not to be very scrupulous about the means resorted to for effecting the object, and the present instance is no exception to the custom. The editor commences by trying to be ironical about the claims of science in culture, and quotes from our prospectus the remark that it is “of the highest concern that thought should be brought into the exactest harmony with things.” We are still of opinion that the neglect of this requirement is the fundamental defect of education, and we venture to intimate to our critic that this is exactly “ what’s the matter with him.” His statements not only fail to harmonize with the things he is talking about, but they grossly misrepresent them. After quoting some sentences from our prospectus, the editor says :
“ It is therefore painful to find that, when we pass from the well-taken prospectus to the actual monthly, the strict inductive inquiry fades softly away, as in a dissolving view, and in its place blazes out one of the most high-flown of human speculations. The strong bias of the editor as an evolutionist cannot be repressed, and the attempt is made to educate the public mind into the phraseology and methods of what is at best a speculation, under the name of science ! If this were called the Youmans, or Evolution Monthly, the misehicf would be circumscribed ; but, as the doctrine of Evolution, with its offspring, Darwinism, is nothing more yet than a provisional hypothesis, based on a prion reasonings, and not on any valid induction of facts, the attempt to clothe it in the imperial garb of science, and set it for an arbiter of all beliefs, is greatly to be deprecated in the interest of true culture.”
The statement hero made, that under editorial bias our pages have been set ablaze with evolution speculations in violation of prospective pledges, is simply not true. We promised our readers to represent the present state of thought on the leading questions that are agitating the scientific world. The doctrine of evolution, as everybody knows, is one of these questions, and had we avoided it we should have broken our promise, and broken faith with our readers. Nor has the subject received the excessive attention that is charged. Our first volume, just completed, contains about 2. hundred main or leading articles, and of these but three deal with the subject of Evolution or Darwinism, and one of them is an attack upon its fundamental principle. Of the articles contributed by the editor, not one has been devoted to the objectalleged—“that of educating the popular mind into the phraseology and methods of this speculation.” Nor is there a single article in the whole volume that gives any explanation of either the phraseology or the methods of the doctrine of Evolution. A few references to it there have heen, as in the addresses of Dr. Carpenter and Prof. Gray, before eminent scientific bodies, and as occurs in the able article of Prof. Clifford in the present number; but these references are incidental and unavoidable: they result from the prominence of the question in the scientific world, and its consequent recognition in current scientific literature. And yet it pleases the editor of Scribner's to tell his readers that under an uncontrolled personal bias our pages are so fired with this mischievous doctrine that the name of the MONTHLY ought to be changed to prevent its evil influence.
It now remains to consider the more serious imputation, that our pages have been perverted to the diffusion of spurious science. According to the editor of Scribner's, the doctrine of evolution is not a result of true science—not an induction from facts, but a “high-flown,” “a priori" “speculation.” And here, again, we have to note that this writer is not very particular to make his thought harmonize with the things he is talking about. His statement is as wrong as he could get it—-just 180° from the truth ; and, if the ignorance he evinces be any measure of the general ignorance, we cannot too quickly begin the neglected work of “ educating the popular mind " into the rudiments of the subject. "We purpose now to show that the Hypothesis of Evolution is not an a priori speculation, but a true scientific induction ; and not only so, but it is the antagonist and successor of a priori speculations which had been in vogue for many centuries before the inductive method arose.
What is the fundamental conception of the doctrine of Evolution ? It is “ that the universe and all that it contains did not come into existence in the condition that we now know it, nor in any thing like that condition.” It implies that the heavens as they appear above us, the earth as it exists beneath us, the hosts of living creatures that occupy it, and humanity as we now know it, “ are merely the final terms in an immense series of changes, which have been brought about in the course of immeasurable time.” It affirms vast changes in past periods ; that these changes have been according to a method, and that this method has been of the nature of an unfolding. The essential changes of evolution have been comprehensively formulated as from the simple to the complex, from the homogeneous to the heterogeneous, from the general to the special. Is this an a priori speculation, that is, an idea formed before observation and experience of the facts to which it applies; or is it a scientific induction, that is, an idea formed after the facts are known, and based upon them ?
As regards the stellar and planetary universe, its origin from an all-diffused nebulous mist was taught by Kant a century ago. This view was subsequently elaborated by Laplace the mathemetician, and Herschel the astronomer, into the Nebular Hypothesis, which Avas the outcome of the whole body of knoAvn astronomical facts. This hypothesis affirmed the progressive condensation and differentiation of the nebulous mass through successive stages to more and more concrete and specialized groups, systems, and orbs. That the solar system was gradually formed in the Avay the nebular hypothesis implies, and that its facts can be explained by that hypothesis and no other, is noAV the general belief of astronomers. Consisting of more than one hundred and fifty bodies, revolving and circulating according to one grand method, it has been pointed out by Prof. Leconte that there are no less than three hundred and seventy facts concerning the distribution, form, and motions, of the sun and planets, which are the simple consequences of the nebular hypothesis, and can be accounted for in no other way. The nebular hypothesis is the doctrine of to-day, in its application to the most perfect of the sciences, and it is nothing less or other than an hypothesis of astronomic evolution. Are we to be told that it is hut an a priori speculation ? On the contrary, has it not replaced an a priori cosmogony that swayed the human mind for thousands of years before the solar system was discovered ?
As regards the earth, it has been studied by the method of science for more than a century, and the result is, a vast mass of facts and inductions which make up our knowledge of geology. All these go to establish one proposition, viz., that our planet is not what it was millions of years ago, but has undergone a series of developing changes resulting in the present order of things. Our eminent geologist, Prof. Dana, in his manual, says : “This law of specialization—the general being before the special—is the law of all development. The egg is at first a simple unit, and, gradually, part after part of the new structure is evolved, that which is most fundamental appearing earliest, until the being is complete in all its outer and minor details. The principle is exhibited in the physical history of the globe—which was first a featureless globe of fire, then had its oceans and dry land, in course of time received mountains and rivers, and finally all those diversities of surface which now characterize it. Again, the climates began with universal tropics; and at last the diversities of the present day.” Is this to be accounted a high-flown a priori speculation, or a vast and valid induction from a hundred years’ study of the facts of Nature? Let it be remembered that, according to the highest authorities, inductive geology was put back two centuries by the enslavement of the human mind to an old a priori speculation in regard to the age of the world.
The study of the course of life upon the earth shows that it conforms to the same great plan. The life of the globe a few millions of years ago was a very different thing from what it is now. Different races of plants and animals have appeared and disappeared in slow succession, and their remains are found entombed in successive rock-formations. The facts are a part of geology, and have been arrived at by the same processes of observation and induction that have revealed the order and history of the stratified systems. The course of life upon the earth has conformed to a method, and that method is universally described as a progress and a development. It shows an advance from the simpler to the more complex, from the general to the special, from the lower to the higher; in short, it is an evolution in the strictest sense. There was, first, a period of no life—the azoic age ; then appeared the lower forms of life, vegetable and animal ; then higher and higher kinds, until man, the highest of all, appeared last. The progress evinces continuity, harmony, and gradation. As remarked by Mr. Dana, “the beginning of an age will be in the midst of a preceding age; and the marks of the future coming out to view are to he regarded as prophetic of that future. The age of mammals was foreshadowed by the appearance of mammals long before in the course of the reptilian age, and the age of reptiles was prophesied in types that lived in the earlier Carboniferous age.” The low’er forms that perish do not reappear, and, as Mr. Wallace observes, “ no group or species has coiné into existence twice,” but “ every species has come into existence coincident, both in space and time, with a preexisting, closely-allied species.” That the great advancing movement of life has been a divergence, an opening out, or an evolution, is incontestable, and is admitted by the highest biological authorities. It is proved by the fact that, if we go back a million of years or so, there is an obvious convergence of types, or the different kinds of animals will have to be represented as nearer together in characters, and, as we recede still farther into the past, the approximation becomes still closer. Prof. Owen says he has “never omitted a proper opportunity for impressing the results of observations showing the more generalized structures of extinct, as compared with the more specialized form of recent animals.” Prof. Agassiz takes a similar position, insisting strongly that “The more ancient animals resemble the embryonic forms of existing species.” Mr. Wallace says : “ As we go back into past time and meet with the fossil remains of more and more ancient races of extinct animals we find that many of them actually are intermediate between distinct groups of existing animals.” Prof. Cope remarks: “That the existing state of the geological record of organic types should be regarded as any thing but a fragment is, from our stand-point, quite preposterous. And more, it may be assumed with safety, that when completed, it will furnish us with a series of regular successions, with but slight and regular interruptions, if any, from the species which represented the simplest beginnings of life at the dawn of creation, to those which have displayed complication and power in a later or in the present period. For the labors of the paleontologist are daily bringing to light structures intermediate between those never before so connected, thus creating lines of succession where before were only interruptions.” Is the great conclusion of an unfolding method in the order of life which is based upon a vast body of biological facts, and supported by the powerful analogies of an unfolding order in other parts of nature, to be characterized as a highflown a priori speculation ? or is it a result of strict inductive inquiry, which replaces an a priori hypothesis of life that prevailed for ages before science had entered upon its study ?
Again, humanity is not now what it was in ages long past. That man’s existence upon earth dates back to a far profounder antiquity than has formerly been believed, is a clear induction from an extensive array of facts. Be the time longer or shorter, an immense series of changes has taken place in the history of the race. A few thousand years ago Europe was barbarous, and its inhabitants warred and worked with implements of stone. Society was rude, low, homogeneous, and undeveloped. Its movement has been a slow unfolding into diversity and specialty. There has been an increase of human capabilities, a rise in intelligence, an advance of morals, a growing capacity of social cooperation, a multiplication of arts and industries, augmented power over Nature, an emergence of institutions, and in short, an evolution of civilization. This is a, broad induction, from the facts of history, from the facts of prehistoricarchaeology, and from the facts of anthropology, and it is fast taking theplace of the old a priori speculation) that the'course of humanity has been at degeneracy, and which was firmly believed until science reversed the method! of studying the subject.
Sir Charles Lyell, it will hardly be denied, is one of the most learned and able of living geologists. His painstaking conscientiousness asan observer and his judicial caution and calmness as an inductive reasoner are beyond question. For fifty years he has studied the subject of life in connection with the past changes of the globe, and has embodied his conclusions in his various geological works.. In. the earlier of these works, which passed through many editions, he accepted the old traditional view of the origin of life. But, as his studies enlarged, that view broke down so completely that he has formally abandoned it. In the tenth edition of his “Principles of Geology,” published in 18G7, and in the eleventh edition of the same work now just issued, he has adopted the theory of evolution in its application to the phenomena of terrestrial life. The presidents of the British Association for the Advancement of Science, Grove, Hooker, Huxley, and Carpenter, in their inaugural addresses, and Prof. Gray in his late address as president of the American Scientific Association, have proclaimed their adherence to the doctrine of evolution. Prof. Cope, one of the most able and accomplished of American zoologists, affirms that the truth of the development hypothesis is held “to bo infinitely probable by a majority of the exponents of the natural sciences, and is held as absolutely demonstrated by another portion.” It has been widely accepted by the younger naturalists of this country, more generally by those of England, and still more extensively by those of Germany, as a guiding principle in the work of investigation. An intelligent German naturalist said to Prof. Giekie, of the Edinburgh University : “You are still discussing in England whether or not the theory of Darwin can be true. We have got a long way beyond that here. His theory is now our common startingpoint.”
Facts like these will have weight with thoughtful persons, but the editor of Scribner's sees through the illusion. All these masters of science and working-students of Nature have been lured from the path of true induction by the ignis fatuus of a high-flown a priori speculation.
We have shown the separate establishment of a principle of evolution by independent workers in different branches of science. On the broad basis of the facts and inductions that have been reached by tlu’ee centux-ies of investigation in the several domains of natural phenomena, rests the hypothesis of universal evolution. The coordination of these diverse and alien orders of facts, and the synthesis of inductions, by which the grand generalization was arrived at, we owe to the genius of Herbert Spencex*. With a knowledge of modern science that John Stuart Mill has pronounced “ encyclopedic,” with a grasp of method and a capacity of organization which, on the authority of the Saturday Iievieic, has not been equalled in England since Newton, and with the power of a “giant mind,” as Dr. McCosh declares, to wield and shape his extensive scientific materials, Mr. Spencer has worked out the px-inciplo of universal evolution by the rigid logic of inductive science. In each division of his exposition the first step has been to marshal the facts ; to sift and methodize the data. The next step has been to generalize the facts, or to establish the inductions warranted by the data. Finally he verifies these inductions by showing that they follow from previously established principles, and harmonize with them. The conditions by which all science has been created are thus strictly complied with. The conception of all natux’e, as in a slow pi*ocess of movement to a higher state—of an ever-advancing and evei*-perfecting order—of a universe in evolution, is no fantastic speculation brought down to us by tradition fronx the dreaming childhood of the race, but it is a definite verifiable principle educed fx’om a more comprehensive range of facts than any other generalization ever attempted —the outgrowth of the ripest knowledge, and which is coercing the assent of the most disciplined intellects of the world. The principle in question is no barren formula to be classed with the empty a priori speculations which have figured so largely in the past career of the human mind. It is the result of the steady concentration of the intellect of man for hundreds of years upon the realities that surround us, and is the profoundest answer yet given to man’s questionings of the mystery of being. It is the latest interpretation of the ongoings of the world, and brings with it the possibility of a new and more stable philosophy of things than we have yet known—a philosophy not spun from mystical a priori fancies, but constructed from the valid truths of science, and anchored in the depths of demonstrated knowledge.
An able writer in the Quarterly Remero (London) for July,in discussing the modern school of thought and Herbert Spencer’s relation to it, says : “ The two deepest scientific principles now known of all those relating to material things are, the law of gravitation and the law of evolution.” The principle is here recognized as more than a hypothesis and more even than a theory, it is a law in the same sense that gravitation is a law. The proof of evolution indeed is very far from being so complete as that of gravitation. But its claims as an established law are not therefore invalidated, for the accepted truths of science by no means rest upon equal amounts of evidence. From the newness of the systematic investigation of the principle, from the imperfection of knowledge in many spheres of its application, and from the stupendous reach of its operation, it is impossible that there should not be many deficiencies in its proof. It has its outstanding and unresolved difficulties which it may take long to clear up. Truths grow—they are examples of evolution. All great generalizations have been arrived at gradually ; never at once by complete demonstration. There are first long foreshadowing preludes in which a principle is discerned as emerging into increasing distinctness. It is then accepted on grounds of probability, and preponderating proofs, and as an advance on previous beliefs. If a theory becomes increasingly consonant with facts, and steadily makes way against inexorable criticism, though it has grave difficulties, it will be accepted, and these difficulties will be left to the future. It was so w'ith the law of gravitation. “ The Newtonian theory was beset by palpable contradictions in its results till many years after Newton’s death, yet all sound philosophers embraced it. The motion of the apsides of the moon’s orbit was with singular honesty confessed by Newton to be, in fact, nearly twice as great as calculation from theory made it ; and this contradiction remained an outstanding, palpable objection, yet without occasioning any misgiving as to the general truth of gravitation, until the error was explained and the calculation rectified by Clairault.”
And so it is in other branches of science. The undulating theory of light is accepted by all physicists, but still has its difficulties. The theory of heat is not without its anomalies. The chemical theory of respiration is generally adopted, but there are facts thaL still oppose it. It is claimed by'none, that the evidence of the law of evolution is complete, but it is a growing conviction of those who know the subject best, that the evidence in its favor preponderates overwhelmingly. Nor is it dependent upon any of its special interpretations. Darwin may be in error, Huxley may be wrong, Mivart may be wide of the mark, Haeckel may be mistaken, Cope may misjudge, and Spencer be at fault ; but, in common with a large and increasing body of scientific men, they are all agreed as to one thing, that evolution is a great and established fact—a wide and valid induction from the observed order of Nature, the complete elucidation of which is the grand scientific task of the future. It is in this sense that we hold to the doctrine of evolution.
In our prospectus we referred to the increasing number of those who desire to know whither inquiry is tending, what old ideas are perishing, and what new ones are rising into acceptance ; and we said that our periodical was commenced with the intention of meeting the wants of these more perfectly than any other. The editor of Scribner's refers to this as a “magnificent promise,” and dilates upon the transcendent editorial attributes required to realize it. To this we reply, “Not if the specimen of Scribnerian science we have here considered is to be taken as the standard.” And if we may be permitted to imitate the bad example of Scribner's editor, and meddle for a moment with what is none of our business, we should say that he had better stick to his fiction and his versemaking, and not deviate into that foreign field where nothing is to be gained by cajoling public ignorance or catering to public prejudice, and where “ the supreme concern is, to bring thought into the exactest harmony with things.”