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Lecture 11. The Concept of Evolution.

§ 1. A Question of Terms. § 2. The Evolution of Organisms Contrasted with Inorganic Genesis. § 3. Organic Evolution Contrasted with the History of Human Societies. § 4. Definition of the Concept of Organic Evolution. § 5. May Evolution Have Been a Process of Analytic Simplifying, not of Synthetic Complexifying? § 6. The Logical Validity of the Evolution Formula. § 7. Difficulties in the Way of Concrete Evolution Theory Lead to Hypotheses of Transcendental Underpinning. § 8. In What Sense Is Organic Evolution Continuous? § 9. In What Sense Is Organic Evolution Progressive?

THERE are two fundamental biological questions: What are living creatures, statically and dynamically, intact and in all their parts?; and, How have they come to be as they are, individually and racially? In the preceding ten lectures we have been concerned with organisms as they are; we pass now to the problem of their evolution. Our general aim remains:—to state the outstanding results of a scientific study of Animate Nature, so that it may be seen whether they are conformable with other results of human experience. We do not argue from the empirical facts to any transcendental conclusion, for that is bound to be bad argument. We try to state the facts.

§ 1. A Question of Terms.

It must be confessed that the study of organic evolution has been hampered by a plethora of words and a dearth of facts. This is not unnatural, for the idea of testing evolutionary hypotheses concretely is hardly older than Darwin, and the shortness of human life is discouraging to experimentation with organisms. The results of many years are usually small in amount. It is only now and then that a pioneer like Mendel is able to take a great stride, and to give his successors a clue that enables them to take others. Impatient therefore of the slow but sure inductive method, naturalists are ever flying kites of hypotheses and there is no department of science so wordy as ætiology.

On the other hand, one of the difficulties is that we have too few words. The same word is used with many meanings, and, like a tool put to many uses, becomes blunted and fallacious. So is it with the word ‘evolution’.

Whatever be his personal classification every one recognises that there are in our world three spheres which cosmosphere—from the solar system to the dew-drop, from the moon to the moonstone, from the sea to the snow-crystal—the Domain of the Inorganic, where formulations are in terms of matter and motion—formulations, which, whether they exhaust the reality or not, get close enough to it to be thoroughly reliable for practical purposes and ventures.

Secondly, there is the biosphere, the Realm of Organisms, where the laws of matter and motion still hold, but are no longer exhaustive, since another aspect of reality has welled-up, which we call life. And since even simple un-bodied creatures go a-hunting and show purposive behaviour, we find it difficult to separate off life from mind. We cannot say much about plants which we do not know how to waken from their dreams, but for the animal world we have clearly to do in any typical case with a Body-Mind or Mind-Body.

Thirdly, there is the sociosphere, the Kingdom of Man, where mechanism is in many departments transcended or sublimed, where even the science of the individual is transcended, for human beings in societies behave in a way which cannot be formulated in terms of individual Biology and Psychology. The homing bird transcends the boomerang, and a purely Natural History account of social activity or social evolution leaves much out.

So we have:—

the Kingdom of Man

the Realm of Organisms

and the Domain of the Inorganic

well marked off from one another, and it seems on the face of it likely that fallacy will result from using the same word ‘evolution’ for all the processes of becoming that are observable in these diverse fields. We hear of the evolution of the solar system, of scenery, of chemical elements, the evolution of organisms, of species, of consciousness, of mind, of man, the evolution of societary forms, of institutions, of language, of religions, the evolution of evolution-theories. Now the use of the same word, especially a semi-technical word, suggests that we have to do throughout with a similar, perhaps a continuous process. But this begs several questions. No matter how convinced we may be as to Continuity, we must not assume that the processes that have led to the inorganic domain being what it is are also those which account for the becoming of organisms, or that human history is nothing more than a continuation of organic evolution. A staircase is continuous, but there are successive steps, and so in evolution there seem to have been epoch-making steps of ‘creative synthesis’.

The following suggestions as to terms are offered. For the process of becoming in the inorganic domain, when there is more or less lasting change from one form of equilibrium to another, we might perhaps use the word genesis, and speak, for clearness sake, of the genesis of the solar system or of the moon. Many geologists speak of the genesis of ores and mountain-ranges. It is clear that in the case of the solar system, for instance, we have nothing like the succession of generations, nothing like the sifting process, nothing like the experimenting with existences which is so characteristic of that sublime adventure which we call organic evolution.

In the realm of organisms let us use the word development for the individual's becoming, for its ontogeny, for the expression of the inheritance amid appropriate nurture. Let us keep the word evolution for the phylogeny of the race as distinguished from the ontogeny of the individual.

Then let us keep the word history for the human Kingdom of ends, where social persons are the new actualities.

What words are used matters, perhaps, little; the point is that fallacy may be lessened by using differential terms, by speaking of the genesis of the solar system, the development of the chick, the evolution of birds, and the history of institutions.

§ 2. The Evolution of Organisms Contrasted with Inorganic Genesis.

Looking backwards, we may say that evolution within the realm of organisms differs from genesis in the domain of the inorganic in three outstanding ways. First, the discrete material systems involved are organisms,—more than mechanisms, a differentia which implies, as we have seen, alternatives, genuine agency, endeavour, some measure of profitable enregistering of experiences, and in certain cases the efficiency of what we call mind.

Secondly, the capacity of organic variation which is distinctive of living creatures, is only adumbrated among non-living things. A living unity, whether a full-grown organism or an implicit organism (the germ-cell), gives rise to something new. A genius is born, a mutation occurs; this is something apart from the ubiquitous flux of weathering, rusting, and the like in the inorganic world. The latter corresponds to the wear and tear of organisms, the disintegration and ageing, the incorporation of the substance of one creature into that of another. It is one thing to say with the Greek philosopher “all things flow”; it is another to recognise creative evolution. For an approach to organic variation we must look to such phenomena as the change of one crystalline form into another, or the elaboration of a carbon compound in certain surroundings, or, nearest of all, perhaps, the change of Uranium into Radium and Helium.

But, third, when an inorganic material system—whether a cloud or a mineral—changes from one form or phase to another, it has its analogue rather in organic development than in organic evolution. For organic evolution implies a succession of generations, a staking of individual lives and losing them, a sacrifice of variants and of types and even of races, a sifting so that many who run the race and fight the fight with success fail eventually to inherit the promises. Even if the chemical evolutionist gives us a genealogical tree of Radium-lead, through Radium to Uranium (with successive losses of Helium), we have only an analogy to organic pedigree.

It is indeed tempting to compare the conflict of forces in the inorganic domain and the resulting equilibrium with the struggle for existence among organisms and the resulting adaptations, to compare both with the conflict of human races and what may result therefrom, but it is probably more fallacious than useful. The similarities are at best formal, except that in all cases—in inorganic genesis, in organic evolution, and in social history—we are dealing with processes of change.

We dwell on these distinctions because they are not really easy, because they are often ignored, and because our whole system of thought depends on our answer to the question whether organic evolution is adequately described as a mechanical process. In his famous article in the 9th edition of the Encyclopœdia Britannica, Prof. James Sully defined evolution as a “natural history of the cosmos, including organic beings, expressed in physical terms as a mechanical process”. We have given some reasons for regarding this definition as scientifically unsound. The vital striving and struggling characteristic of the realm of organisms is something apart from and finer than even the music of the spheres.

Let us give the contrast we are emphasising its most generalised statement. From the purely physical point of view—a very abstract one—the history of the world has been and continues to be a series of redistributions of matter and energy. Even if we think of radium pouring forth power like an inexhaustible fountain, we make it conform with physical theory by speaking of the potential energy liberated by a dissolution of the atoms. The world is like a change-office, without increase or decrease in its initial stock. We always stand in the middle of an equation, past equalling future. It is for the biologist to correct this partial view, for to him the possible that grows out of the past is new and in some measure unpredictable. The psychologist has a similar task. M. Bergson has done great service in emphasising this truth.

§ 3. Organic Evolution Contrasted with the History of Human Societies.

Looking forwards now, we may recognise that organic evolution differs from the history of human society in three outstanding ways. (1) The variations that count among plants and animals are changes in the germ-plasm, but the moving and shaking of the Kingdom of Man need not be thus restricted, as is obvious in ‘revivals’ and ‘revolutions’, for instance, which are certainly social variations. (2) The important evolutionary registration among plants and animals is in the natural inheritance, but in the Kingdom of Man the extra-organismal or social heritage bulks largely. (3) Among social animals there is not more than a dim adumbration of what is characteristic in mankind,—that a social ideal of some sort is defined, and that organisations are formed, both on the temporal and spiritual side, to realise it.

The naturalist is not disposed to agree with a too facile exaggeration of the difference made by the fact that Man is a social person. There is a great deal of what might be called social tissue at pre-human levels. Especially on the instinctive line of evolution are there quaint forms of social organisation which command our admiration though for ethical reasons we cannot take any imitative advantage of their subtlety. There is amazement for us in the sterile worker-caste in bees, in the soldier-caste among termites, in the massacres of the superfluous, in the nutritive partnership between many wasps and their young larvæ—mothers feeding young and young feeding mothers, in the way the tailor-ants use their children as needle and thread!

§ 4. Definition of the Concept of Organic Evolution.

By a method of contrast, then, we are seeking to render more precise the concept of organic evolution. It is distinguishable from the genesis of the solar system or of a range of mountains, and from the history of political institutions or social usages. Moreover, we speak of the development of the chick, but of the evolution of birds. What more can be said? Organic evolution is a continuous natural process of racial change in a definite direction whereby distinctively new individualities arise, take root, and flourish, sometimes alongside of, and sometimes, sooner or later, in place of the originative stock. The domestic breeds of pigeons and fowls are apparently the results of evolutionary change whose origins are still with us in the Rock Dove and the Jungle Fowl. In the Crab-Apple by the wayside, whose promise is more obviously suggested by its flowers than by its fruit, there is the sturdy plebeian ancestor of all the delicate aristocrats of the orchard; into the unpromising wild kale by the sea-shore we have to read back all our cabbages, cauliflowers, and curly greens. In these and in many other cases the original stock still persists.

It is otherwise, however, when we inquire into the origin of creatures like the domestic horse or dog; the only certainty is our ignorance. And this is even more emphatic when we try to discover the pedigree of any of the great classes of animals: Whence came mammals or birds? What was the origin of molluscs or of insects? In many cases the ancestral stocks are unknown; in other cases where they have been detected by some probability they are separated by great gaps from their modern descendants. In general, while there are long-lived conservative types, like Lingula, which persist, with little change or none, from age to age, evolution has meant replacement of old by new.

In many cases what we dimly descry is a vigorous stock from which tentative offshoots arise, which lead to much or to little, while the main branch grows on and, as if it were purified, gives rise to fine fruit. Thus from the early Primate stock there diverged off at various levels New World Monkeys, Old World Monkeys, small Apes and great Apes, leaving a humanoid branch none the worse, to say the least.

In a concrete way the concept of Evolution means that the present is the child of the past and the parent of the future, that the present-day fauna and flora and all the system of inter-relations have arisen in a natural knowable way from a preceding state of affairs on the whole somewhat simpler, and that from forms and inter-relations simpler still, and so on backwards till we lose all clues in the thick mist of life's beginnings.

“As in the development of a fugue,” Samuel Butler said, “where when the subject and counter-subject have been announced, there must thenceforth be nothing new, and yet all must be new, so throughout organic nature—which is a fugue developed to great length from a very simple subject—everything is linked on to and grows out of that which comes next to it in order—errors and omissions excepted.”

§ 5. May Evolution Have Been a Process of Analytic Simplifying, not of Synthetic Complexifying?

Since the publication of the Origin of Species there have been various outcrops of the idea that the process of evolution may have been not by synthetic complexifying but by analytic emancipation or exfoliation of originally complex buds. An Italian naturalist has at great length sought to show that reptiles evolved from birds, not birds from reptiles, and the backboneless from the backboned, not the other way round. This reads like a modern version of the suggestion made by Plato in the Timæus that the whole organic world might be formed by degradation from man who was created first. No one has taken these heretical views very seriously, if only for the reason that the rock record is wholly against such an interpretation of what has occurred. A general survey shows that amphibians appeared after fishes, and reptiles after ampihibians, and birds after reptiles. A more detailed survey of particular lineages, like that of horses or elephants, shows that the earlier forms in the series are the more generalised.

But while a crude topsy-turvy view must be dismissed without hesitation, some find good reason to pause before rejecting the idea that the process of evolution may have been analytic not synthetic. We must remember that the concrete problem of accounting for any of the leading types of organisms or any of the so-called big lifts in evolution is extraordinarily difficult and very far from solution. We must remember that it is extremely difficult to suggest a theory of the origin of the distinctively new. We must remember that in the cases of evolution that are nearest to us, namely in domestic animals and cultivated plants, what is suggested by the facts is not synthetic complexifying but analytic simplification. We are delightedly familiar with the range of colours in modern Sweet Peas, but have we realised the Mendelian conclusion that these are all due to an unpacking of the inheritance of the wild ancestor—which was brought from Sicily at the end of the seventeenth century? There is no doubt, Professor Bateson tells us, that our cultivated Sweet Peas “have been derived from the one wild bi-colour form by a process of successive removals”. (Presidential Address Brit. Association, Australia, 1914, p. 18.)

Professor Bateson is one of the foremost living ætiologists, and respect is due to his pronouncement that we must begin seriously to consider “whether the course of Evolution can at all reasonably be represented as an unpacking of an original complex, which contained within itself the whole range of diversity which living things present…As we have got to recognise that there has been an Evolution, that somehow or other the forms of life have arisen from fewer forms, we may as well see whether we are limited to the old view that evolutionary progress is from the simple to the complex, and whether after all it is conceivable that the process was the other way about…At first it may seem rank absurdity to suppose that the primordial form or forms of protoplasm could have contained complexity enough to produce the divers types of life. But is it easier to imagine that these powers could have been conveyed by extrinsic additions?”

Professor Bateson asks us not to think of the primordial forms of life as necessarily very simple. We are to think of them as richly endowed with initiatives and potentialities. He is particularly inclined to this view because his extraordinarily fine experimental work has led him to conclude that most of the novelties that appear nowadays in garden and breeding-pen are due to the removal of hindrances that suppress or mask underlying qualities. There has been an unpacking of a crowded treasure-box and a placing of assorted Jewels in special caskets. Mr. Bateson appears to believe that the reason why we are not all geniuses is not that we have not got it in us, but that we cannot get it out. When the genius emerges it is not really a new achievement that has been made, it is that certain hindrances or inhibitors have been removed. So the process of evolution has been a succession of liberations rather than of achievements, a succession of gains by loss.

In this interesting theory we recognise two truths: first, that when genuine living creatures did first appear as going concerns, they had within them the secret of a possible glorious future (ce n'est que le premier pas qui coûte); and second, that many apparently novel acquisitions are due to the removal of some inhibitor or some mask or some complexity in the hindrance. We are unwilling, however, to accept Professor Bateson's picture as a complete one, and that for several reasons. (1) The first is that it makes the origin and nature of the primordial organisms too utterly miraculous if we suppose them to have had such a rich stock of initiatives and implications. (2) It seems to lead to a very mechanical picture of evolution, as if it were just an age-long unrolling of a stupendous gramophone record. Time is required for unrolling the record, but time does not count for the gramophone, as it counts for the organism which trades with it. Space is required for unrolling the record, but space does not count for the gramophone as it counts for the organism, which trafficks with its environment. (3) Given an artistic genius, we may assert that all that he did in the last forty years of his life was in him when he was twenty-one. But is this necessarily an accurate statement? His achievements at thirty are the product of his hereditary nature, admittedly well-expressed at his coming of age, but also of what lie has made of his life and his chances, and of what society has made of him. The organism works on a compound interest principle; especially in its mental aspect it is made as well as born. And what is true of an explicit individual that he makes experiments in self-expression may be true for aught we know of those implicit, telescoped-down individualities which we call germ-cells. In any case, we see no reason to part with the idea of the full-grown organism as an agent that shares in its own evolution.

In so far as Professor Bateson's view is just a paradoxical way of saying that there is nothing evolved which was not, in kind, originally involved; that there is nothing of lasting value in the end which was not present, in kind, in the beginning, we have no fault to find with it, provided it be clearly recognised that it necessitates the assumption that the ancestral creatures had the primordia of mental as well as of bodily organisation. If we ourselves are asked to state how we conceive that the Primordials did embody all the promise and potency of, say, bee-kind, or bird-kind, or mankind, we cannot answer, except by suggesting that the question is not rightly put. What the Primordials embodied was the next stage in the Systema Naturæ.

But if Mr. Bateson's view implies that the apparent origin of the new is illusory, that creative evolution is a fiction, that evolution means unfolding (evolutio) not new-formation (epigenesis), it does not seem to us to be in accordance with the facts.

In the study of individual development embryologists have to do with the emergence of the obviously complex from the apparently simple. We mean by apparently simple that the egg has no organs or tissues or the like, but all the modern Work on germ-cells points to the conclusion that for each distinct feature in the adult there is in the germ-cell a something which divides and persists. Thus arises what Prof. E. B. Wilson calls the puzzle of the microcosm: “Is the hen's egg fundamentally as complex as the hen, and is development merely the transformation of one kind of complexity into another”?

We can picture a conjurer's box full of exquisite wound-up contrivances which begin to unwind and expand one after the other when the lid is opened. As the springs uncoil an extraordinarily complex mass is formed which half fills the stage. But there is no real increase in complexity, even if the springs interlace. For a tangled skein is not more complex than an ordered one. Now, development is much more than this uncoiling of springs set agoing by opening the lid of a box, for each cell into which the egg-cell divides is a living unit and is able to relate itself in an organic way to its neighbours, so that the final result is a dynamic system—an active organisation—far more complex than the original egg-cell.

What holds in the development of the microcosm is true also in the evolution of the macrocosm. The descendants are really more complex than the primordial ancestors, for the process has meant a multiplication of genuine individualities or agents, who relate themselves to one another organically, who enter into subtle inter-relations with their inanimate environment, whence also new complexities spring.

A number of immigrants on a prospecting voyage take possession of an island and in the course of centuries a great, nation is built up. All the human material in that nation has arisen from what was in the ship, but it outrages common sense to maintain that the end is not more complex than the beginning, for that is to deny to men and women any creative agency, to pretend that inter-relations established by genuine agents do not spell new organisation. This view reduces human history to the level of a puppet-show; in short, it is a false simplicity, a ‘materialism’.

What biology seems justified in holding firm to is, that there has been a frequent epigenesis or new formation, a frequent outcrop of genuine novelties. Without insisting on the epigenetic character of the emergence of feeling and other forms of consciousness, we mean, in concrete language, that there was a time when there were no insects; they came into being, and they were new ideas. There was a time when there were no birds; they came into being, and they were new ideas. It may be very naïve on the biologist's part, but it does not appear likely that any argument that being is a fixed quantity will affect his belief that insects and birds were downright novelties. Evolution is racial epigenesis—the making actual of what was only potential; but it is more, it is a series of great inventions,—in a way, a succession of new worlds.

§ 6. The Logical Validity of the Evolution Formula.

The evolution formula is not demonstrable like that of gravitation. It is a way of looking at things that fits, that is luminous, that meets with no contradiction, that serves as an organon of discovery. It is the only known scientific way of answering the question: How has the present-day system of Animate Nature come into being?

All the facts of botany and zoology may be used as evidences of evolution if we know enough about them, and yet their cumulative weight cannot be called strictly demonstrative. This much may be said, however, that both past and present become uncomfortably magical unless the evolutionary formulation be true. For how otherwise can we account, for instance, for the twisting and moulding of the same fundamental materials, notably bones and muscles, to make the fore-limb of a frog, the paddle of a turtle, the wing of a bird, the fore-leg of a horse, the flipper of a whale, the wing of a bat, or the arm of man? Can these homologies, this ‘adherence to type’ be understood save as indicating blood-relationship? How can we interpret the numerous useless vestigial structures in higher animals except as the dwindled relics of structures which were well-developed and functional in ancestral forms? The two sets of teeth in whalebone whales that never cut the gum, the deeply buried representative of hip girdle and hind leg in many Cetaceans, the hint of a third eyelid in man, are they conceivable except as historical vestiges, like the unsounded letters in many words, to use Darwin's comparison, or like the functionless buttons and buttonholes in our clothing? What apart from evolution can be the significance of the classifiability of organisms into varieties, species, genera, families, orders, classes, and phyla, of the ‘connecting links’ and ‘synthetic types’? There seems no alternative between a miraculous world and an evolved one when we learn that the blood of a horse mingles harmoniously with that of an ass, and a hare's with a rabbit's, while man's blood added to any of them produces destruction of corpuscles. Blood-relationship is not a metaphor; its degree can be measured by a precipitate. We cannot visit the exhibitions of pigeons and poultry, of cats and canaries, of cabbages and chrysanthemums, of roses and apples, without asking: If Man has utilised organic variability to such purpose in a short time, what may not Nature have effected in the course of many millions of years? The rock record discloses the lineage of horse and elephant, crocodile and ammonite; it yields missing links to the sceptic; it shows us above all that, as age succeeded age, there was an emergence of nobler and nobler forms of life.

We remember, too, how Darwin on his ‘Beagle’ voyage, which discovered a new world, was struck by the simple fact that the modern distribution of those strange survivals, the sloths and armadillos, was centred round the burying-ground of the huge majority of their race. And clinching the whole argument, though we admit that it is only presumptive, there is the embryological evidence. The embryos of reptiles, birds, and mammals travel in their development for a considerable distance along the same road, or along approximately parallel roads, before they diverge, each on its own path; and in the making of organs there is many a bend of the road very puzzling except on the theory that the individual development is to some extent a re-treading of the track which the race blazed in its evolution. What can be made of the gill-clefts in the region of the neck in embryo reptiles, birds, and mammals, of no use for breathing, of no use at all save the first, which becomes the Eustachian tube, unless they be genuine relics of aquatic ancestors breathing in fish-fashion?

The strength of the evolution-theory as a modal formula of becoming is that it works well. It is a useful organon of research. It clears things up and prompts discovery. There is no other scientific formulation in the field. But it is not without elements of weakness. In the first place, we are remarkably ignorant in regard to the pedigree of some of the most important types, such as backboned animals. This is not to be wondered at, because so many of the great branches had begun to diverge from the genealogical tree in very ancient times, of which there is relatively little fossil-record. In regard to some more recent originations, such as elephants and horses, the pedigree is very well known.

In the second place, apart from the general formula, little light has been thrown on the factors at work in the establishment of most of the great new departures. How little we can say of the factors operative in the emergence of Birds from a Saurian stock or of Man from a Primate stock! Some people talk as if they believed that one had only to mutter the word ‘Evolution’ for difficulties to disappear.

In the third place, there is the general and central difficulty that we know so very little—serious ætiology practically dates from Darwin—in regard to the causes of variation itself, on which all evolution depends.

§ 7. Difficulties in the Way of Concrete Evolution Theory Lead to Hypotheses of Transcendental Underpinning.

The difficulty of giving a concrete account of the evolution of a phylum such as Vertebrates, or of an organ like the eye, or of a phenomenon like migration, is great; but it will probably disappear as knowledge grows. It must be remembered, however, that the difficulty led so distinguished a pioneer as Alfred Russel Wallace and some others with him to postulate the operation of spiritual influxes at particularly critical stages in the evolution, as in the origin of man's mathematical, musical, and artistic faculties, or in the introduction of consciousness, or in the emergence of organisms themselves. Wallace spoke of “different degrees of spiritual influx”, as it were welling up from “an unseen universe—a world of spirit, to which the world of matter is altogether subordinate”…“A change in essential nature (due, probably, to causes of a higher order than those of the material universe) took place at the several stages of progress which I have indicated; a change which may be none the less real because absolutely imperceptible at its point of origin, as is the change that takes place in the curve in which a body is moving when the application of some new force causes the curve to be slightly altered” (Darwinism, 1889, p. 476).

Without confining ourselves to Wallace's position, let us inquire into the theories of spiritual influx. (a) In some forms they amount to a premature abandonment of the scientific mode of attacking the problem. For scientific formulation proposes to work with verifiable factors, and that cannot be said of spiritual influxes operating in organic evolution. We see reason for attaching much importance to the influence of mind in evolution,—a capacity for behaviour of which we cannot give a protoplasmic account, but this is amenable to experimentation and to verification by competent observers. (b) A spiritual influx theory is apt to be associated with a fanciful dualism, implying two worlds, one of which only occasionally intrudes effectively into the other. This means an abandonment of the idea of continuity of process. There are some who regard the biologist's conviction of a process without gaps as an illusion, who frankly avow their belief in extrinsic factors of another order than those admitting of scientific study, which now and again move organisms like puppets in a show; and Wallace spoke of “a change in essential nature (due, probably, to causes of a higher order than those of the material universe)”. This view may seem to us to break the law of parsimony, but it would be difficult to prove it false. ‘What we cannot accept, however, is Wallace's assurance that on his theory the process of evolution was none the less continuous. The Ice Age, he said, introduced new factors into the process of earth-sculpture, but there was no discontinuity. But ‘spiritual influxes’ do not seem to be as amenable to scientific treatment as glacial influences have been. Wallace apparently thought of the material universe being underpinned throughout by a spiritual universe, and we have no right to object to that, but what the scientific mind recoils from is the suggestion that a spiritual influx occasionally operates dramatically, helping the organism over difficult stiles, (c) It is possible that some of those who hold by a ‘spiritual influx’ theory mean little more than those who are dissatisfied with a mechanistic evolutionism. They recognise that more is involved in the evolving organism than is recognised by those who think that it can be exhaustively summed up in terms of matter and motion. In mankind we are sure that ideas count as a vera causa in evolution; the question is how far biologists can discern in animal evolution psychical factors that can be tested and experimented with by appropriate methods. One of the protagonists of the mechanistic interpretation of man declares, without seeing the humour of it, that he can demonstrate the physiological effects of an anticipation of an operation. A mechanistic anticipation!

In seeking some reconciliation of religious conviction and the results of science various attempts have been made, like Wallace's, “to get past the scientific position without the danger of being taken prisoner”. In regard to the worst of these we quote Prof. G. J. Blewett (1907, p. 53):

“One of these attempts to ‘get past the scientific position’ is so fundamentally bad as to deserve special mention—the endeavour to justify belief in God by seeking to find gaps in the continuity of nature. It is true that a God thus made manifest—made manifest not by the greatness and harmony of nature, not by its abiding law and continuous order, but by its rents and gaps—would be no worthy object of religious devotion. But that is only the beginning of the matter. Once you shatter the continuity of nature, you shatter more than Materialism. You shatter the possibility of all science whatever. You open up the gulf of universal scepticism, and Materialism disappears in it, it is true, but along with it will disappear Theism and Theology and the rational basis for every sort of religion except two, between which men will continue to choose according to their individual dispositions—Stoicism (as a practical temper, not as a philosophy) and Epicureanism.”

§ 8. In What Sense Is Organic Evolution Continuous?

By continuity in the process of organic evolution the biologist does not mean that there are no breaks, no leaps, no brusque novelties. For there is a growing belief in the importance of transilient variations or mutations. These appear suddenly, without intergrades connecting them to the parents. The Proteus leaps as well as creeps. But though Professor Bateson calls them discontinuous variations, there is no discontinuity in their emergence any more than there is in the metamorphosis of a caterpillar into a butterfly. By continuity in evolution the biologist means that there are no gaps, no intrusions. As Prof. W. R. Sorley puts it (Proc. Brit. Acad., IV., 1909, p. 5): “Each stage in the process with all that it contains must find its explanation within the universe and not in something outside.” One may say more, that each stage is the outcome of what precedes. Whether we think of the evolution of Animate Nature as a whole, or of particular individualities within it, there is a twofold continuity to he recognised. There is the flesh-and-blood linkage, the genetic ‘enchaînement desêtres’, the continuous succession of immortal germ-cells inspite of transformation of species here and extinction there and blind alleys somewhere else. But there is also a continuity in the external staging, in the extra-organismal systematisations, in what we have called the web of life. This is of extraordinary importance in the case of mankind; naturalists have not allowed enough for it in the case of animal and plant organisms.

But we must not exaggerate the idea of continuity. Both as regards the organism and its environment of inter-relations we have to recognise that with all the continuity there is continual change. Birds are continuous with reptiles, but not continuations of them, and at the time of their evolution there was a correlated change in the genesis of the earth which opened to birds a new world indeed.

While birds are very different from reptiles, indubitable new ideas, it is possible to imagine how a fore-limb could become a wing and a scale a feather, and that sort of discontinuity is familiar to all students of evolution. On the other hand, it is certain, from centuries of failures, that by no jugglery of words can we account for thinking in terms of matter and motion. Therefore the alternatives (1) to regard the scientific belief in evolution as in part at least an illusion, since what comes later, e.g., thinking, is distinct in kind from what comes earlier; or (2) to suppose that the lowest animals are potentially psychical; with, as Sir Francis Darwin puts it (Presidential Address, British Association, 1908), “faint copy of all we know as consciousness in ourselves”. The first position is not easy, for the evolutionary explanation is practically proved along anatomical and physiological lines; the second position is not easy, for the ‘faint copy’ becomes faint indeed when we pass to the simplest organisms.

Here again we venture to quote from Professor Blewett's Study of Nature and the Vision of God (1907, p. 53):

“In insisting upon the continuity of nature, men of science have been better theologians than the theologians themselves. If God exists at all He is the God of all nature and of every natural law. There are no gaps in His workmanship, no breaches of continuity in His activity. All nature is an activity of His, and every natural law a principle of that activity. If the theologians would be true to theology, what they have to do is to protest, not against the principle of continuity, but against too narrow a reading of it, and too narrow an application of it to reality. The principle of continuity is unworthily treated if it is limited to certain physical and chemical processes. The true field of the principle of continuity is the total history in time, the total evolution, of the universe. And so viewed, it is simply one way of apprehending the essential rationality of God and of the divine action in nature and in history.”

§ 8. In What Sense Is Organic Evolution Progressive?

If increasing differentiation and integration is progress, then Organic Evolution is most certainly progressive. Not only when envisaged as a whole, but when attention is focussed on particular lines, Animate Nature exhibits, as age succeeds ago, an increasing differentiation or complexifying and an increasing integration or correlating. A locomotive of the twentieth century shows, when compared with Stephenson's engine, a much greater division of labour and specialisation of parts; it also shows a much greater harmony of action and controllability. The same is revealed in organic nature, when we compare an oak tree with a mushroom, or a bird with a sponge. As age has succeeded age, life has boon in the main creeping upwards. It is not that we naïvely rank as progress any change that makes a creature liker ourselves; there is a discernible standard with objectively verifiable features—increasing differentiation and integration—in a word organisation.

Three admissions must be made. (1) It is plain that evolution may be down as well as up, and that the gates of parasitism and other facile slopes of degenerate life are always open. The tapeworm in its inglorious ease is as much an outcome of evolution as the lark at heaven's gate. It is a misunderstanding to suppose that a result necessarily acquires value, in any human sense, by being the outcome of evolution, or that evolution is synonymous with progress. (2) There are many corners where organisms seem to have run riot in exuberant complication, often extraordinarily beautiful, but without further significance so far as we have yet been able to discern. We shall return to the interesting fact that these instances of exuberance are sometimes in conditions of life that are peculiarly secure, where the pruning knife of Natural Selection is in abeyance. (3) Some of the most remarkable achievements of evolution have passed away in their prime without leaving direct descendants. It is probable, however, as we shall illustrate later on, that the distinctive gains of these lost races are, sometimes at least, conserved along collateral lines.

To be chastised out of our mind is the smug conceit that all evolutionary change, especially that in which Man is concerned, is ipso facto progressive, whatever that may mean. Perhaps the lightest whip is best: “Organic life, we are told, has developed gradually from the protozoon to the philosopher, and this development, we are assured, is indubitably an advance. Unfortunately it is the philosopher, not the protozoon, who gives us this assurance, and we can have no security that the impartial outsider would agree with the philosopher's self-complacent assumption” (Bertrand Russell on the “Philosophy of Evolution” in Mysticism and Logic, 1918). A sense of humour forbids any retort to so true a jest.

These admissions notwithstanding, the large fact is certain that on the whole there has been for many millions of years progressive differentiation and integration along diverse lines, an increasingly complex and masterly behaviour, a growing emancipation of mind and an approximation to personality. This is the largest fact to be borne in mind in our interpretation of evolution. The process has been on the whole progressive. With Lotze we hear “an onward-advancing melody”.

We certainly miss part of the impressiveness and suggestiveness of the evolutionary process if we do not realise its solidarity. It concerns a developing system, like a great organism, in which the exuberance of one part and the tardiness of another cannot be said to disturb the balanced movement of the whole. Twigs shoot forth out of due time and arc broken off; huge branches of extraordinary magnificence (like the lost races of Giant Reptiles) fall crashing to the ground, but the tree lives on in order and balance. And if we consider not our biosphere, merely, but the whole cosmic system that we know, we get the same impression. Evolution is based on order and works out in order. “A certain unity manifests itself then in the Cosmos, a unity comparable to that which the development of an organism reveals” (Joussain, 1912, p. 185).

Without losing sight of real differences we may believe in a continuity of evolutionary process from inorganic genesis to human history, but it must be confessed that there is a good deal of scientific faith implied. Philosophically it seems fair to say that if organic evolution is traced back into inorganic genesis, it must also be traced forward into human history, and the process regarded, as far as we can, as a whole. It is a misleading abstraction “to treat the world of nature as a fact complete in itself, a system finished without man…Man is organic to nature, and nature is organic to man. It is a false abstraction to try to take the world apart from the central fact in which it so obviously finds expression” (Pringle-Pattison, 1917, p. 177).

SUMMARY.

The scientific theory of evolution has suffered from a scarcity of facts and a plethora of words, yet also from a dearth of words. For the term ‘evolution’ is used with fallacious elasticity for processes of becoming in very different fields. The use of differential terms for the three great orders of facts may be suggested. In the domain of the inorganic we study the genesis of the solar system, of a range of mountains, or of precious stones. In the realm of organisms we study the development (or ontogeny) of the individual and the evolution (or phylogeny) of the species or race. In the kingdom of man we study the history of institutions, social activities, and the like.

Organic evolution differs from inorganic genesis: since organism transcends mechanism; since organismal variation is quite different from the ubiquitous inorganic flux (which has its analogue in ageing, dying, re-incorporation, etc.); and since inorganic genesis, as in the making of a star, has its analogue in the individual development of the organism, not in racial evolution, where much shares in the process of becoming that does not figure in the final result.

Organic evolution differs from the history of human societary forms: because social variations are not restricted to the germ-plasm; because the extra-organismal or social heritage bulks so largely; and because there is not in the realm of organisms more than a dim adumbration of deliberate selection, towards a social ideal, by means of social sifting-organisations. Yet there are quaint forms of social organisation on the instinctive line which command admiration, though, for ethical reasons, Man cannot take any imitative advantage of their subtlety.

Organic evolution is a continuous natural process of racial change in a definite direction, whereby distinctively new individualities arise, take root and flourish, alongside of, or in place of the originative stock. In a general way, it means that the present, with its fine fauna and flora and the inter-relations of these, is the product of the past and the promise of the future.

It is necessary, however, to consider the view that evolution may have been not synthetic complexifying, but analytic simplification,—by a removal of inhibitions which has allowed the original richness of endownment to express itself with increasing fulness. This view of evolution is open to several serious objections which show its untenability. In so far as the view means that there is nothing evolved which was not in kind originally involved, that there is nothing of lasting value in the end which was not present in kind in the beginning, it is acceptable. But Biology is justified in regarding evolution as a racial epigenesis.

The evolution-formula cannot be demonstrated like that of gravitation; it is acceptable because it fits and is never contradicted by facts. The so-called “evidences of evolution”—anatomical, embryological, palæontological, and so on—are multitudinous; but they are never more than presumptive. The real strength of the evolutionist's position is in the value of the theory as an organon, There is no other scientific formulation in the field. The weakness of the evolutionist's position is that he remains very ignorant as to the pedigree of many of the most important types, such as Vertebrates; as to the factors leading to the establishment of great new departures, such as birds or men; and as to the causes of variation itself. But the inquiry is young.

The difficulties in the way of concrete evolution-theory, which will probably disappear as knowledge grows, have prompted the suggestion made by Alfred Russel Wallace and others that special spiritual influxes have operated at various critical stages in the process of becoming. This means a premature abandonment of the scientific problem, which proposes to work with verifiable factors; it suggests a fanciful dualism of two worlds, one of which occasionally intrudes effectively into the other; it gives up the idea of continuity of process. It is not to be identified with the conviction that more is involved in evolving organisms than is recognised by those who insist on restricting their formulation to mechanistic terms.

Evolution is continuous in the sense that it is a process without gaps. But it is not without steps, for discontinuous variations or mutations seem to be important realities. What is meant by the continuity of evolution is that each stage in the process has its full precondition (we do not say interpretation) in what precedes. There is a flesh-and-blood continuity of lineage (‘enchaînement des ȴtres’), and there is also continuity in the extra-organismal order which includes the established system of inter-relations.

In regard to the progressiveness of Animate Evolution, three admissions must first be made. There have been many retrogressive lines, notably in adaptation to parasitism and sedentary life. There are also many corners where organisms seem to have run riot in exuberant complication, often extraordinarily beautiful, but without further significance that we can discern. Some of the most striking achievements of evolution, such as the flying dragons, have passed away in their prime without leaving direct descendants. It is probable, however, that the distinctive gains of these lost races may have been conserved on collateral lines.

These admissions notwithstanding, the large fact is certain that on the whole there has been progressive differentiation and integration along diverse lines, an increase in the complexity and masterfulness of behaviour, a growing emancipation of mind, and an approximation to personality. This is the fundamental fact to be borne in mind in our interpretation of evolution.