Popular Science Monthly/Volume 1/July 1872/Mr Martineau on Evolution
|MR. MARTINEAU ON EVOLUTION.|
THE propriety of dealing with the leading criticisms that have been made on the general doctrine set forth in "First Principles"—more especially criticisms on the metaphysical aspects of that doctrine—has been from time to time pressed upon me. Having recently been led to undertake a subject outside of, though ancillary to, the work with which I am chiefly occupied, a contemplated reply to these criticisms has beer put aside for a while. The article by Mr. Martineau, in the April number of the Contemporary Review, on "The Place of Mind in Nature, and Intuition in Man," while it reminded me of this postponed essay, because containing further criticisms to be met, did not lead to any change of intention. I learn, however, that Mr. Martineau's arguments, which, though not avowedly directed against propositions asserted or implied in "First Principles," tell against them by implication, are supposed by some to be conclusive, and that, in the absence of replies, it will be assumed that no replies can be made. It seems desirable, therefore, to notice these arguments at once—especially as the essential ones may, I think, be effectually dealt with in comparatively small space.
The first definite objection which Mr. Martineau raises is, that the hypothesis of general evolution is powerless to account even for the simpler orders of facts in the absence of numerous different substances. He argues that, were matter all of one kind, no such phenomena as chemical changes would be possible, and that, "in order to start the world on its chemical career, you must enlarge its capital, and present it with an outfit of heterogeneous constituents. Try, therefore, the effect of such a gift; fling into the preexisting caldron the whole list of recognized elementary substances, and give leave to their affinities to work." The intended implication obviously is, that there must exist the separately-created elements before evolution can begin. Here, however, Mr. Martineau makes an assumption which few, if any, chemists will commit themselves to, and which many will distinctly deny. There are no "recognized elementary substances," if the expression means substances known to be elementary. What chemists, for convenience' sake, call elementary substances, are merely substances which they have thus far failed to decompose; but, bearing in mind past experiences, they do not dare to say that they are absolutely undecomposable. Water was taken to be an element for more than 2,000 years, and then was proved to be a compound; and, until Davy brought a galvanic current to bear upon them, the alkalies and the earths were supposed to be elements. So little true is it that the "recognized elementary substances" are supposed to be absolutely elementary, that there has been much speculation among chemists respecting the process of compounding and recompounding by which they have been formed out of some ultimate substance—some chemists having supposed the atom hydrogen to be the unit of composition, but others having contended that the atomic weights of so-called elements are not thus interpretable. If I remember rightly, Sir John Herschel was one, among others, who, some five-and-twenty years ago, threw out suggestions respecting the composition of them. What was at that time a suspicion has now become practically a certainty. Spectrum analysis yields results wholly irreconcilable with the assumption that the conventionally-named simple substances are really simple. Each yields a spectrum having lines varying in number from two to eighty—lines every one of which implies the intercepting of ethereal undulations of a certain order by something oscillating in unison or in harmony with them. Were iron absolutely elementary, it is not conceivable that its atom could intercept ethereal undulations of eighty different orders: though it does not follow that its molecule contains as many separate atoms as there are lines in its spectrum, it must clearly be a complex molecule. The evidence thus gained points to the conclusion that, out of some primordial unit, the so-called elements arise by compounding and recompounding; just as by the compounding and recompounding of elements there arise oxides, and acids, and salts. And this hypothesis is entirely in harmony with the phenomena of allotropy. Various so-called elementary substances have several forms under which they present quite different properties. The semitransparent, colorless, extremely active substance commonly called phosphorus may be so changed as to become opaque, dark red, and inert. Like changes are known to occur in some gaseous, non-metallic elements, as oxygen; and also in metallic elements, as antimony. These total changes of properties, brought about without any changes to be called chemical, are interpretable only as due to molecular arrangements; and, by showing that difference of property is produced by difference of arrangement, they support the inference otherwise to be drawn, that the properties of different elements result from differences of arrangement produced by the compounding and recompounding of ultimate homogeneous units. Thus Mr. Martineau's objection, which at best would imply a turning of our ignorance of the nature of elements into positive knowledge that they are simple, is, in fact, to be met by two sets of evidences, which distinctly imply that they are compound.
Mr. Martineau next alleges that a fatal difficulty is put in the way of the General Doctrine of Evolution by the existence of a chasm between the living and the not-living. He says: "But with all your enlargement of data, turn them as you will, at the end of every passage which they explore, the door of life is closed against them still." Here again our ignorance is employed to play the part of knowledge: the fact that we do not know distinctly how an alleged transition has taken place is transformed into the fact that no transition has taken place. We have over again the mode of argument which until lately was thought conclusive—because the genesis of each species of creature had not been explained, therefore each species must be specially created. Merely noting this, however, I go on to remark that scientific discovery is day by day narrowing the chasm, or, to use Mr. Martineau's metaphor, "opening the door." Not many years since, it was held as certain that the chemical compounds distinguished as organic could not be formed artificially. Now, more than a thousand organic compounds have been formed artificially. Chemists have discovered the art of building them up, from the simpler to the more complex, and do not doubt that they will eventually produce the most complex. Moreover, the phenomena attending isomeric change give a clew to those movements which are the only indications we have of life in its lowest forms. In various colloidal substances, including the albuminoid, isomeric change is accompanied by contraction or expansion, and consequent motion; and, in such primordial types as the Protogenes of Haeckel, which do not differ in appearance from minute portions of albumen, the observed motions are comprehensible as accompanying isomeric changes caused by variations in surrounding physical actions. The probability of this interpretation will be seen on remembering the evidence we have that, in the higher organisms, the functions are essentially effected by isomeric changes from one to another of the multitudinous forms which protein assumes. Thus the reply to this objection is, first, that there is going on from both sides a rapid narrowing of the chasm supposed to be impassable; and, second, that, even were the chasm not in course of being filled up, we should no more be justified in therefore assuming a supernatural commencement of life than Kepler was justified in assuming that there were guiding-spirits to keep the planets in their orbits, because he did not see how else they were to be kept in their orbits.
The third definite objection made by Mr. Martineau is of kindred nature. The Hypothesis of Evolution is, he thinks, met by the insurmountable difficulty that plant-life and animal life are absolutely distinct. He says:
This is an extremely unfortunate objection to raise. For, though there are no transitions from vegetal to animal at the places Mr. Martineau names, where, indeed, no biologist would dream of looking for them, yet the connection between the two great kingdoms of living things is so complete that separation is now regarded as impossible. For a long time naturalists endeavored to frame definitions such as would, the one include all plants and exclude all animals, and the other include all animals and exclude all plants. But they have been so repeatedly foiled in the attempt that they have given it up. There is no chemical distinction that holds; there is no structural distinction that holds; there is no functional distinction that holds; there is no distinction as to mode of existence that holds. Large groups of the simpler animals contain chlorophyll, and decompose carbonic acid under the influence of light as plants do. Large groups of the simpler plants, as you may observe from the diatoms from any stagnant pool, are as actively locomotive as the minute creatures classed as animals seen along with them; and among these lowest types of living things it is common for the life to be now predominantly animal and presently to become predominantly vegetal. The very name zoospores, given to germs of algæ, which for a while swim about actively by means of cilia, and presently settling down grow into plant-forms, is given because of this conspicuous community of nature. So complete is this community of nature that for some time past many naturalists have wished to establish for these lowest types a sub-kingdom intermediate between the animal and the vegetal: the reason against this course being, however, that the difficulty crops up afresh at any assumed places where this intermediate sub-kingdom may be supposed to join the other two. Thus the assumption on which Mr. Martineau proceeds is diametrically opposed to the conviction of naturalists in general.
Though I do not perceive that it is specifically stated, there appears to be tacitly implied a fourth difficulty of an allied kind—the difficulty that there is no possibility of transition from life of the simplest kind to mind. Mr. Martineau says, indeed, that there can be "with only vital resources, as in the vegetal world, no beginning of mind;" apparently leaving it to be inferred that in the animal world the resources are such as to make the "beginning of mind" comprehensible. Whether any consciousness of an incongruity between the conception of "germs of mind as well as the inferior elements," and his hypothesis of universal mind as the cause of evolution, prevented Mr. Martineau from pressing this objection, I do not know. But, had he asserted a chasm between mind and bodily life, for which there is certainly quite as much reason as for asserting a chasm between animal life and vegetal life, the difficulties in his way would have been no less insuperable. For those lowest forms of irritability in the animal kingdom, which, I suppose, Mr. Martineau refers to as the "beginning of mind," are not distinguishable from the irritability which plants display: they in no greater degree imply consciousness. If the sudden folding of a sensitive-plant's leaf when touched, or the spreading out of the stamens in a cistus-flower when you brush them, is to be considered as a vital action of a purely physical kind, then so too must be considered the equally slow retraction of a polype's tentacles. And yet, from this simple motion of an animal having no nervous system, we may pass by insensible stages through ever-complicating forms of actions, with their accompanying signs of feeling and intelligence, until we reach the highest. Even apart from the evidence derived from the ascending grades of animals up from zoophytes, as they are significantly named, it needs only to observe the evolution of a single animal to see how baseless is the assumption that there exists any break or chasm between the life that shows no mind and the life that shows mind. The yolk of an egg which the cook has just broken not only yields no sign of mind, but yields no sign of life. It does not respond to a stimulus as much even as many plants do. Had the egg, instead of being broken by the cook, been left under the hen for a certain time, the yolk would have passed by infinitesimal gradations through a series of forms ending in the chick, and by similarly infinitesimal gradations would have arisen those functions which end in the chick breaking its shell; and which, when it gets out, show themselves in running about, distinguishing and picking up food, and squeaking if hurt. When did the feeling begin, and how did there come into existence that power of perception which the chick's actions show? Should it be objected that the chick's actions are mainly automatic, I will not dwell on the fact that, though they are largely so, the chick manifestly has feeling and therefore consciousness, but I will accept the objection, and propose that instead we take the human being. The course of development before birth is just of the same general kind; and similarly, at a certain stage, begins to be accompanied by reflex movements. At birth there is displayed an amount of mind certainly not greater than that of the chick—there is no power of running from danger, no power of distinguishing and picking up food. If we say the chick is unintelligent, we must certainly say the infant is unintelligent. And yet from the unintelligence of the infant to the intelligence of the adult, there is an advance by steps so small that on no day is the amount of mind shown appreciably different from that shown on preceding and succeeding days. Thus the tacit assumption, that there exists a break, is not simply gratuitous, but one that is negatived by the most obvious facts.
And now, having dealt with the essential objections raised by Mr. Martineau to the Hypothesis of Evolution as it is presented under that purely scientific form which generalizes the process of things, firstly as observed, and secondly as inferred from certain ultimate principles, let me go on to examine that form of the Hypothesis which he propounds—Evolution as determined by Mind and Will—Evolution as prearranged by a Divine Actor. For Mr. Martineau apparently abandons the primitive theory of creation by "fiat of Almighty Will" and also the theory of creation by manufacture—by "a contriving and adapting power," and seems to believe in Evolution; requiring only that "an originating mind" shall be taken as its antecedent. Let us ask, first, in what relation Mr. Martineau conceives the "originating mind" to stand to the evolving universe. From some passages it is inferable that he considers the "presence of mind" to be everywhere needful. He says:
This seems to be an unmistakable assertion that, whenever evolution is going on, mind is then and there behind it. At the close of the argument, however, a quite different conception is implied. Mr. Martineau says:
It would take too much space to deal fully with the various questions which this passage raises. There is the question, Whence come these "Forces," spoken of as separate from the "Will of God"—did they preexist? Then what becomes of the divine power? Do they exist by the divine Will? Then what kind of nature is that by which they act on the divine Will? Again, there is the question, how do these deputy-forces cooperate in each particular phenomenon, if the presiding Will is not there present to control them? Either an organ which develops into fitness for its function, develops by the cooperation of these forces only under the direction of Mind there present, or they do it in the absence of Mind? If they do it in the absence of Mind, the hypothesis is given up; and if the "originating mind" is required to be then and there present, it must be regarded as universally present. Once more there is the question, If "His thought" is related to them [these forces] as, in Man, the mental force is related to all below it, how can "His thought" be regarded as the cause of evolution? In man the mental force is related to the forces below it neither as a creator of them, nor as a regulator of them, save in a very limited way: the greater part of the forces present in man, both structural and functional, defy the mental force absolutely. Not dwelling on these questions, however, it will suffice to point out the entire incongruity of this conception with the previous conception which I have quoted. Assuming that, when the choice is pressed on him, Mr. Martineau will choose the first, which alone has any thing like defensibility, let us go on to ask how far Evolution is made comprehensible by postulating Mind, universally immanent, as its cause.
In metaphysical controversy, many of the propositions propounded and accepted as quite believable are absolutely inconceivable. There is a perpetual confusing of actual ideas with what are nothing but pseud-ideas. No distinction is made between propositions that contain real thoughts, and propositions that are only the forms of thoughts. A thinkable proposition is one of which the two terms can be brought together in consciousness under the relation said to exist between them. But very often, when the subject of a proposition has been thought of as something known, and when the predicate has been thought of as something known, and when the relation alleged between them has been thought of as a known relation, it is supposed that the proposition itself has been thought. The thinking separately of the elements of a proposition is mistaken for the thinking of them in the combination which the proposition affirms. And hence it continually happens that propositions which cannot in truth be rendered into thought at all are supposed to be not only thought but believed. The proposition that Evolution is caused by Mind is one of this nature. The two terms are separately intelligible; but they can be regarded in the relation of effect and cause only so long as no attempt is made to put them together in the relation.
The only thing which any one knows as mind is the series of his own states of consciousness. The mind so known to each person, and inferred by each to be present in others, has the essential characters, that its components are limited by one another, and that it is itself localized both in time and space. If I am asked to frame a notion of mind, divested of all those structural traits under which alone I am conscious of mind in myself, I cannot do it. I know nothing of thought save as carried on in terms originally derived from the effects wrought by objects on me. A mental act is an unintelligible phrase if I am not to regard it as an act in which states of consciousness are severally assimilated to other states in the series that has gone by, and in which the relations between them are severally assimilated to past relations in this series. I cannot give any meaning to the word Will, unless I am to think of it in terms of contemplated ends, of which some one is preferred.
If, then, I have to conceive Evolution as caused by an "originating Mind," I must conceive this mind as having attributes akin to those of the only mind I know, and without which I cannot conceive mind at all. I will not dwell on the many incongruities hence resulting, by asking how the "originating Mind" is to be thought of as having states produced by things objective to it; as discriminating among these states, and classing them as like and unlike; and as preferring one objective result to another. I will simply ask, What happens if we ascribe to the "originating Mind" the character absolutely essential to the conception of mind, that it consists of a series of states of consciousness? Put a series of states of consciousness as cause, and the evolving universe as effect, and then endeavor to see the last as flowing from the first. It is possible to imagine in some dim kind of way a series of states of consciousness serving as antecedent to any one of the movements I see going on; for my own states of consciousness are often indirectly the antecedents to such movements. But how if I attempt to think of such a series as antecedent to all actions throughout the universe—to the motions of the multitudinous stars through space to the revolutions of all their planets round therm, to the gyrations of all these planets on their axes, to the infinitely-multiplied physical processes going on in each of these suns and planets? I cannot even think of a series of states of consciousness as causing the relatively small group of actions going on over the earth's surface; I cannot even think of it as antecedent to all the various winds and the dissolving clouds they bear, to the currents of all the rivers, and the guiding actions of all the glaciers; still less can I think of it as antecedent to the infinity of processes simultaneously going on in all the plants that cover the globe, from tropical palms down to polar lichens, and in all the animals that roam among them, and the insects that buzz about them. Even to a single small set of these multitudinous terrestrial changes, I cannot conceive as antecedent a series of states of consciousness—cannot, for instance, think of it as causing the hundred thousand breakers that are at this instant curling over the shores of England. How, then, is it possible for me to conceive an "originating Mind," which I must represent to myself as a series of states of consciousness, being antecedent to the infinity of changes simultaneously going on in worlds too numerous to count, dispersed throughout a space that baffles imagination? If, to account for this infinitude of physical changes everywhere going on, "Mind must be conceived as there under the guise of simple Dynamics," then the reply is that, to be conceived as there, Mind must be divested of all attributes by which it Is distinguished; and that when thus divested of its distinguishing attributes, the conception disappears—the word Mind stands for a blank. If Mr. Martineau takes refuge in the entirely different and, as it seems to me, incongruous hypothesis of something like a plurality of minds—if he accepts, as he seems to do, the doctrine that you cannot explain Evolution "unless among your primordial elements you scatter already the germs of Mind as well as the inferior elements"—if the insuperable difficulties I have just pointed out are to be met by assuming a local series of states of consciousness for each phenomenon, then we are obviously carried back to something like the old fetichistic notion, with the difference only, that the assumed spiritual agencies are indefinitely multiplied. Clearly, therefore, the proposition that an "originating Mind" is the cause of Evolution is a proposition that can be entertained so long only as no attempt is made to unite in thought its two terms in the alleged relation. But when the attempt to unite them is made, the proposition turns out to be not simply unprovable, but unthinkable.
Here let me guard myself against a misinterpretation very likely to be put upon the foregoing arguments—especially by those who have read the Essay to which they reply. The statements of that Essay carry the implication that all who adhere to the hypothesis it combats imagine they have solved the mystery of things when they have explained the processes of Evolution as naturally caused. Mr. Martineau tacitly represents them as believing that, when every thing has been interpreted in terms of Matter and Motion, nothing remains to be explained. This, however, is by no means the fact. The Doctrine of Evolution, under its purely scientific form, does not involve Materialism, though its opponents persistently represent it as doing so. Indeed, among adherents of it who are friends of mine, there are those who speak of the Materialism of Buchner and his school, with a contempt certainly not less than that felt by Mr. Martineau. To show how entirely anti-materialistic my own view is, I may, perhaps, without impropriety, quote passages which I have written elsewhere:
It is thus, I think, manifest that the difference between Mr. Martineau's view and the view he opposes is by no means so. wide as he makes it appear; and further, it seems to me that such difference as exists is, in truth, rather the reverse of that which his exposition implies. Briefly expressed, the difference is this, that, when he thinks there is no mystery, the doctrine he combats recognizes a mystery. Speaking for myself only, I may say that, agreeing entirely with Mr. Martineau in repudiating the materialistic interpretation as utterly futile, I differ from him simply in this, that while he says he has found another interpretation, I confess that I cannot find any interpretation; while he holds that he can understand the Power which is manifested in things, I feel obliged to admit, after many failures, that I cannot understand, it. This contrast does not appear of the kind which bis Essay tacitly implies. I fail to perceive humility in the belief that human thought is capable of comprehending that which is behind appearances; and I do not see how piety is especially exemplified in the assertion that the Universe contains no mode of existence higher in Nature than that which is present to us in consciousness. On the contrary, I think it quite a defensible proposition that humility is better shown by a confession of incompetence to grasp in thought the Cause of all things; and that the religious sentiment may find a higher sphere in the belief that the Ultimate Power is no more representable in terms of human consciousness than human consciousness is representable in terms of a plant's functions.
Other parts of Mr. Martineau's argument I pass over as being met by implication in the above replies. I will now add only that, should any further explanation be required, I must postpone it until I am free from present special engagements.
- "Principles of Psychology," second edition, vol. i., § 63.
- Ibid., § 272.