SPENCER AS BIOLOGIST—THE DATA OF BIOLOGY
The Principles of Biology—Organic Matter—Metabolism—Definition of Life—The Dynamic Element in Life—Life and Mechanism
The Principles of Biology.—If there is any book that will save a naturalist from being easy-going it is Spencer's Principles of Biology. It is a biological classic, which, in its range and intensity, finds no parallel except in Haeckel's greatest and least known work, the Generelle Morphologie, which was published in 1866 about the same time as the Principles. As one of our foremost biologists, Prof. Lloyd Morgan has said[5]: "What strikes one most forcibly is the extraordinary range and grasp of its author, the piercing keenness of his eye for essentials, his fertility in invention, and the bold sweep of his logical method. In these days of increasingly straitened specialism, it is well that we should feel the influence of a thinker whose powers of generalisation have seldom been equalled and perhaps never surpassed."
[5] Mr Herbert Spencer's Biology, "Natural Science," xiii. (1898) pp. 377-383.
Much that is in The Principles of Biology has now become common biological property; much has been absorbed or independently reached by others; consciously or unconsciously we are now, as it were, standing on Spencer's shoulders, but this should not blind us to the magnitude of Spencer's achievement. The book was more than a careful balance-sheet of the facts of life at a time when that was much needed; it meant orientation and systematisation; it was the introduction of order, clearness, and breadth of view. It gave biology a fresh start by displaying the facts of life and the inductions from these for the first time clearly in the light of evolution. For if the evolution idea is an adequate modal formula of the great process of Becoming, then we need to think of growth, development, differentiation, integration, reproduction, heredity, death—all the big facts—in the light of this. And this is what the Principles of Biology helps us to do. It is of course saturated with the theory of the transmissibility of acquired characters—an idea integral to much of Spencer's thinking—which had hardly begun to be questioned when the work was published, which is now, however, a very moot point indeed. For this and other reasons, we doubt whether Spencer was wise in making a re-edition of what might well have remained as a historical document, especially as the re-edition is not so satisfactory for 1898 as the original was for 1864.
The chief purpose of The Principles of Biology was to interpret the general facts of organic life as results of evolution. Manifestly, as a preliminary step, "it was needful to specify and illustrate these general facts; and needful also to set forth those physical and chemical properties of organic matter which are implied in the interpretation." "What are the antecedent truths taken for granted in Biology, and what are the biological truths, which, apart from theory, may be regarded as established by observation?" Thus Part I. deals with organic matter and its activity or metabolism, the action and reaction between organisms and their environment, the correspondence between organisms and their circumstances, and similar general data. Part II. states the big inductions regarding growth, development, adaptation, heredity, variation, and so on. Part III. deals with the arguments suggestive of organic evolution and with the factors in the process. Part IV. is a detailed interpretation of the evolution of organic structure, and Part V. an analogous interpretation of the evolution of functions. Part VI. deals with the laws of multiplication.
Before illustrating Spencer's workmanship in dealing with these great themes, we cannot but ask what preparation he had for a task so ambitious. He had an inborn interest in Natural History; he had dabbled in Entomology and done a little microscopic work; he had attended lectures by Owen and had enjoyed many a talk with Huxley; he had been influenced by Lamarck, Milne-Edwards, and von Baer; he had read hither and thither in medical and biological literature; but it is manifest that his own admission was true that he was "inadequately equipped for the task." That he succeeded in producing a biological classic is a signal proof of his intellectual strength. He was kept right by his power of laying hold of cardinal facts and by his grip of the Evolution-clue. Not to be forgotten, moreover, was the generous help rendered by Professor Huxley and Sir Joseph Hooker, who checked his proofs. Spencer made but one biological investigation (1865-6), and that of little moment—on the circulation in plants—but his contact with the facts of organic life was by no means superficial. His intelligence was such that he got further into them than most concrete workers have ever done. And in some measure it was an advantage to him in his task that he was no specialist, that he did not know too much. It enabled him to approach the facts with a fresh mind, and to see more clearly the general facts of Biology which lie behind the details of Botany and Natural History. He was in no danger of not seeing the wood for the trees.
Organic Matter.—"In the substances of which organisms are composed, the conditions necessary to that redistribution of Matter and Motion which constitutes Evolution, are fulfilled in a far higher degree than at first appears." Thus the most complex compounds into which Carbon, Hydrogen, Oxygen, and Nitrogen enter, together with small proportions of two other elements (Sulphur and Phosphorus) which very readily oxidise, "have an instability so great that decomposition ensues under ordinary atmospheric conditions"; the component elements have an unusual tendency to unite in different modes of aggregation though in the same proportions, thus forming analogous substances with different properties; the colloid character of the most complex compounds that are instrumental to vital actions gives them great molecular mobility—a plastic quality fitting them for organisation; "while the relatively great inertia of the large and complex organic molecules renders them comparatively incapable of being set in motion by the ethereal undulations, and so reduced to less coherent forms of aggregation, this same inertia facilitates changes of arrangement among their constituent molecules or atoms, since, in proportion as an incident force impresses but little motion on a mass, it is the better able to impress motion on the parts of the mass in relation to one another"; "lastly, the great difference in diffusibility between colloids and crystalloids makes possible in the tissues of organisms a specially rapid redistribution of matter and motion; both because colloids, being easily permeable by crystalloids, can be chemically acted on throughout their whole masses, instead of only on their surfaces; and because the products of decomposition, being also crystalloids, can escape as fast as they are produced, leaving room for further transformations." In short, organic matter is chemically and physically well-suited to be the physical basis of life.
The colloid character of organic matter facilitates modification by arrested momentum or by continuous strain. There is often strong capillary affinity and rapid osmosis. Heat is an important agent of redistribution in the animal organism, and light is an all-important agent of molecular changes in organic substances. But the extreme modifiability of organic matter by chemical agencies is the chief cause of that active molecular rearrangement which organisms, and especially animal organisms, display. In short, the substances of which organisms are built up are specially sensitive to the varied environing influences; "in consequence of its extreme instability organic matter undergoes extensive molecular rearrangements on very slight changes of conditions."
The correlative general fact is that during these extensive molecular rearrangements, there are evolved large amounts of energy, in the form of motion, heat, and even light and electricity. On the one hand the components of organic matter are regarded as falling from positions of unstable equilibrium to positions of stable equilibrium; on the other hand, "they give out in their falls certain momenta—momenta that may be manifested as heat, light, electricity, nerve-force, or mechanical motion, according as the conditions determine." It follows from the law of the Conservation of Energy that "whatever amount of power an organism expends in any shape, is the correlate and equivalent of a power which was taken into it from without."
Metabolism.—"The materials forming the tissues of plants as well as the materials contained in them, are progressively elaborated from the inorganic substances; and the resulting compounds, eaten, and some of them assimilated by animals, pass through successive changes which are, on the average, of an opposite character: the two sets being constructive and destructive. To express changes of both these natures the term 'metabolism' is used; and such of the metabolic changes as result in building up from simple to compound are distinguished as 'anabolic,' while those which result in the falling down from compound to simple are distinguished as 'katabolic.'"
"Regarded as a whole, metabolism includes, in the first place, those anabolic or building-up processes specially characterising plants, during which the impacts of ethereal undulations are stored up in compound molecules of unstable kinds; and it includes, in the second place, those katabolic or tumbling-down changes specially characterising animals, during which this accumulated molecular motion (contained in the food directly or indirectly supplied by plants) is in large measure changed into those molar motions constituting animal activities. There are multitudinous metabolic changes of minor kinds which are ancillary to these—many katabolic changes in plants and many anabolic changes in animals—but these are the essential ones."
Definition of Life.—Spencer's first definition of life (Theory of Population, 1852) was simply "the co-ordination of actions." But he soon saw that this was too wide. "It may be said of the Solar System, with its regularly-recurring movements and its self-balancing perturbations, that it, also, exhibits co-ordination of actions." "A true idea of Life must be an idea of some kind of change or changes." Therefore he carefully considered assimilation on the one hand, as an example of bodily life, and reasoning on the other hand, as an example of that life known as intelligence, and inquired into the common features of these two processes of change. Thus there emerged the formula that life is the definite combination of heterogeneous changes, both simultaneous and successive. But this formula also fails, as he said, by omitting the most distinctive peculiarity. It is universally recognised that living creatures continually exhibit effective response to external stimuli. To be able to do this is the very essence of life, distinguishing its responses from non-vital responses. Thus a clause must be added to the proximate conception, and the formula reads: "Life is the definite combination of heterogeneous changes, both simultaneous and successive, in correspondence with external co-existences and sequences." There are internal relations, namely, "definite combinations of heterogeneous changes, both simultaneous and successive," and there are external relations, "external co-existences and sequences," and life is the connexion of correspondence between them. Thus under its most abstract form, Spencer's conception of Life is:—"The continuous adjustment of internal relations to external relations."
In an appendix to the revised edition of the Principles of Biology, Spencer admits that he had not sufficiently emphasised the fact of co-ordination. "The idea of co-ordination is so cardinal a one that it should be expressed not by implication but overtly." The formula defining the phenomenon of life thus reads: "The definite combination of heterogeneous changes, both simultaneous and successive, co-ordinated into correspondence with external co-existences and sequences." It may be needful to remark that this was not intended to define Life in its essence, but Life as manifested to us. "The ultimate mystery is as great as ever: seeing that there remains unsolved the question: What determines the co-ordination of actions?"
If life be correspondence between internal and external relations, then "allowing a margin for perturbations, the life will continue only while the correspondence continues; the completeness of the life will be proportionate to the completeness of the correspondence; and the life will be perfect only when the correspondence is perfect." As organisms become more differentiated they enter into more complex relations with their environment, and as the environment becomes more complex organisms become more differentiated. The internal and external relations increase in number and intricacy pari passu, and the correspondences between them become more complex, numerous, and persistent. "The highest life is that which, like our own, shows great complexity in the correspondences, great rapidity in the succession of them, and great length in the series of them." "The highest Life is reached when there is some inner relation of actions fitted to meet every outer relation of actions by which the organism can be affected." "This continuous correspondence between inner and outer relations which constitutes Life, and the perfection of which is the perfection of Life, answers completely to that state of organic moving equilibrium which arises in the course of Evolution and tends ever to become more complete."
The Dynamic Element in Life.—But Spencer was not satisfied with his formula of Life. He recognised that there were vital phenomena which were not covered by it. The growth of a gall on a plant, due to irritant substances produced by an insect, shows no internal relations adjusted to external relations; the heart of a frog will live and beat for a long time after excision; the segmentation of an egg shows no correspondence with co-existences and sequences in its environment; when rudimentary organs are partly formed and then absorbed, no adjustment can be alleged between the inner relations which these present and any outer relations: the outer relations they refer to ceased millions of years ago; no correspondence, or part of a correspondence, by which inner actions are made to balance outer actions, can be seen in the dairymaid's laugh or the workman's whistle; the struggles of a boy in an epileptic fit show no correspondence with the co-existences and sequences around him, but they betray vitality as much as do the changing movements of a hawk pursuing a pigeon; "both exhibit that principle of activity which constitutes the essential element in our conception of life."
"When it is said that Life is the definite combination of heterogeneous changes, both simultaneous and successive, in correspondence with external co-existences and sequences, there arises the question—Changes of what?... Still more clearly do we see this insufficiency when we take the more abstract definition—"the continuous adjustment of internal relations to external relations." Relations between what things? is the question to be asked. A relation of which the terms are unspecified does not connote a thought but merely the blank form of a thought. Its value is comparable to that of a cheque on which no amount is written."
This self-criticism led Spencer to the conclusion that "that which gives substance to our idea of Life is a certain unspecified principle of activity. The dynamic element in life is its essential element."
But how are we to conceive of this dynamic element? "Is this principle of activity inherent in organic matter, or is it something superadded?" Spencer at once rejected the second alternative, because the hypothesis of an independent vital principle has a bad pedigree, carrying us back to the ghost-theory of the savage, and because it is an unrepresentable 'pseud-idea,' which cannot even be imagined.
But the alternative of regarding Life as inherent in the substances of the organisms displaying it is also full of difficulties. "The processes which go on in living things are incomprehensible as results of any physical actions known to us." "We are obliged to confess that Life in its essence cannot be conceived in physico-chemical terms. The required principle of activity, which we found cannot be represented as an independent vital principle, we now find cannot be represented as a principle inherent in living matter. If, by assuming its inherence, we think the facts are accounted for, we do but cheat ourselves with pseud-ideas."
"What then are we to say—what are we to think? Simply that in this direction, as in all other directions, our explanations finally bring us face to face with the inexplicable. The Ultimate Reality behind this manifestation, as behind all other manifestations, transcends conception."
"Life as a principle of activity is unknown and unknowable—while its phenomena are accessible in thought the implied noumenon is inaccessible—only the manifestations come within the range of our intelligence, while that which is manifested lies beyond it."
But "our surface knowledge continues to be a knowledge valid of its kind, after recognising the truth that it is only surface knowledge."
The chapter on "The Dynamic Element in Life," which concludes the section of the book called The Data of Biology, was interpolated in the revised edition (1898). It indicates, as it seems to us, that Spencer's point of view had changed considerably since he stereotyped his First Principles. We must pause to consider what this change was.
In his First Principles Spencer wrote: "The task before us is that of exhibiting the phenomena of Evolution in synthetic order. Setting out from an established ultimate principle [the Persistence of Force] it has to be shown that the course of transformation among all kinds of existences cannot but be that which we have seen it to be." [This refers to the formula: Evolution is an integration of matter and concomitant dissipation of motion during which the matter passes from an indefinite, incoherent homogeneity to a definite, coherent heterogeneity; and during which the retained motion undergoes a parallel transformation.] "It has to be shown that the redistribution of matter and motion must everywhere take place in those ways and produce those traits, which celestial bodies, organisms, societies alike display. And it has to be shown that this universality of process results from the same necessity which determines each simplest movement around us, down to the accelerated fall of a stone or the recurrent beat of a harp string. In other words, the phenomena of Evolution have to be deduced from the Persistence of Force. As before said, 'to this an ultimate analysis brings us down; and on this a rational synthesis must build up.'" And again he wrote: "The interpretation of all phenomena in terms of Matter, Motion, and Force, is nothing more than the reduction of our complex symbols of thought to the simplest symbols."
These were brave words, and if we understand them aright it is, to say the least, surprising to be told when we come to the life of organisms that "the processes which go on in living things are incomprehensible as results of any physical actions known to us."
On the first page of the Principles of Biology we read: "The properties of substances, though destroyed to sense by combination, are not destroyed in reality. It follows from the persistence of force, that the properties of a compound are resultants of the properties of its components—resultants in which the properties of the components are severally in full action, though mutually obscured." But on p. 122 it is written: "We find it impossible to conceive Life as emerging from the co-operation of the components."
In the frankest possible way Spencer admitted that his definition of Life did not cover the facts, that it did not recognise the essential or dynamic element, that "Life in its essence cannot be conceived in physico-chemical terms." But if so, it can only be by great faith or great credulity that we can believe that an Evolution-formula in terms of "Matter, Motion, and Force" is adequate to describe its genesis.
At an earlier part of the Data of Biology Spencer assumed the origin of active protoplasm from a combination of inert proteids during the time of the earth's slow cooling, and did not suggest that there was any particular difficulty in the assumption; yet in the end we are told that it is "impossible even to imagine those processes going on in organic matter out of which emerges the dynamic element in Life."
"One can picture," Prof. C. Lloyd Morgan writes,[6] "how certain folk will gloat and 'chortle in their joy' over this confession, for such it will almost inevitably be regarded. But it is not likely that Mr Spencer is here, in so vital a matter, false to the evolution he has done so much to elucidate. The two seemingly contradictory statements are not really contradictory; they are made in different connections; the one in reference to phenomenal causation, the other to noumenal causation—to an underlying 'principle of activity.' The simple statement of fact is that the phenomena of life are data sui generis, and must as such be accepted by science. Just as when oxygen and hydrogen combine to form water, new data for science emerge; so, when protoplasm was evolved, new data emerged which it is the business of science to study. In both cases we believe that the results are due to the operation of natural laws, that is to say, can, with adequate knowledge, be described in terms of antecedence and sequence. But in both cases the results, which we endeavour thus to formulate, are the outcome of principles of activity, the mode of operation of which is inexplicable. We formulate the laws of evolution in terms of antecedence and sequence; we also refer these laws to an underlying cause, the noumenal mode of action of which is inexplicable. This, if I interpret him rightly, is Mr Spencer's meaning."
[6] "Natural Science," xiii., December 1898, p. 380.
Our own impression is that Spencer was guilty of "wobbling" between two modes of interpretation, between scientific description and philosophical explanation, a confusion incident on the fact that his Principles of Biology was also part of his Synthetic Philosophy. Biology as such has of course nothing to do with "the Ultimate Reality behind manifestations" or with the "implied noumenon." And when Spencer says "it is impossible even to imagine those processes going on in organic matter out of which emerges the dynamic element in Life," or when he illustrates his difficulty by pointing out how impossible it is to give a physico-chemical interpretation of the way a plant cell makes its wall, or a coccolith its imbricated covering, or a sponge its spicules, or a hen eats broken egg-shells, we do not believe he was thinking of anything but "phenomenal causation." When he says "The processes which go on in living things are incomprehensible as results of any physical actions known to us," we see no reason to take the edge off this truth by saying that Spencer simply meant that the Ultimate Reality is inaccessible.
In any case, whether Spencer meant that we cannot give any scientific analysis in physico-chemical terms of the unified behaviour of even the simplest organism, or whether he simply meant that the raison d'être, the ultimate reality of life, was an inaccessible noumenon, he confesses that we have "only a surface knowledge"; "only the manifestations come within the range of our intelligence while that which is manifested lies beyond it"; "the order existing among the actions which living things exhibit remains the same whether we know or do not know the nature of that from which the actions originate." This seems to us to sound a more modest note than is heard in the sentence: "The interpretation of all phenomena in terms of Matter, Motion and Force, is nothing more than the reduction of our complex symbols of thought to the simplest symbols."
Life and Mechanism.—But are not all biologists confronted with the difficulty that gave Herbert Spencer pause? Physiological analysis has done much in revealing chains of sequence within the organism, but no vital phenomenon has as yet been redescribed in terms of chemistry and physics. Again and again some success in discovering physico-chemical chains of sequence has awakened the expectation that the dawn of a mechanical theory of life was drawing nigh, but the dawn seems further off than ever. The residual phenomena left uninterpreted by mechanical categories loom out more persistently than they did a century ago. As Bunge once said "the more thoroughly and conscientiously we endeavour to study biological problems, the more are we convinced that even those processes which we have already regarded as explicable by chemical and physical laws, are in reality infinitely more complex, and at present defy any attempt at a mechanical explanation." As Dr J. S. Haldane puts it: "If we look at the phenomena which are capable of being stated, or explained in physico-chemical terms, we see at once that there is nothing in them characteristic of life.... The action of each bodily mechanism, the composition and structure of each organ, are all mutually determined and connected with one another in such a way as at once to distinguish a living organism from anything else. As this mutual determination is the characteristic mark of what is living, it cannot be ignored in the framing of fundamental working hypotheses."
The fact is that we have to regard the living organism as a new synthesis which we cannot at present analyse, and life as an activity which cannot at present be redescribed in terms of the present physical conceptions of matter and energy. And even if a living organism were artificially made, the problem would not be altered; though our conception of what we at present call inanimate might be.
Prof. Karl Pearson states the position from another point of view.
For the biologist as a scientific inquirer "the problem of whether life is or is not a mechanism is not a question of whether the same things, 'matter' and 'force,' are or are not at the back of organic and inorganic phenomena—of what is at the back of either class of sense-impressions we know absolutely nothing—but of whether the conceptual shorthand of the physicist, his ideal world of ether, atom, and molecule, will or will not also suffice to describe the biologist's perceptions." That it does not at present seems the conviction of the majority of physiologists; if it ever should it would be "purely an economy of thought; it would provide the great advantages which flow from the use of one instead of two conceptual shorthands, but it would not 'explain' life any more than the law of gravitation explains the elliptic path of a planet."
"Atom" and "molecule" and the rest are scientific concepts, not phenomenal existences, therefore even if the physicist's formulæ should fit vital phenomena—which they seem very far from doing—there would be no explanation forthcoming, for "mechanism does not explain anything."
Thus, like Spencer, we find the secret of the organism irresoluble in terms of lower categories. But we differ from him inasmuch as we believe that this admission is fatal to his formula of evolution, to his definition of life, and to the coherence of his Synthetic Philosophy.