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Lecture Seventh. Naturalism and Evolution

THE ordinary deistic or dualistic view of the relations of nature, man and God, as we have concluded, must be replaced by a doctrine which, instead of conceiving them as separate spheres only accidentally and arbitrarily related to one another, maintains that they are so intimately connected as to be unintelligible apart from one another. It is at least certain that, starting from their abstract opposition, it is not possible legitimately to bring them together. An attempt, however, may be made to solve the problem, not by connecting the three spheres in an arbitrary and external way, but by showing that they are really reducible to one. Nature, it may be said, includes what is ordinarily opposed to it; for, when we examine our experience at first hand, setting aside all preconceptions, we discover that the only reality known to us is that of nature itself. That is one method of securing unity. Another method is to maintain that nature has no reality apart from the experience of conscious beings, while God is merely a name for the totality of such beings with their experiences. In this way finite and more especially human beings are held to be the only reality, while nature and God are merely the contents of the experience of these beings, hypostatized as independent. On this view—the view of Pluralism—nature and God disappear as independent beings, leaving only the experiences of finite beings. A modification of this theory is that which seeks to combine Pluralism with Theism, affirming that the universe is composed of finite selves, which in their experiences are independent, while in their existence they are dependent upon God. This may be called Theistic Pluralism. Once more it may be said that nature and man have no independent reality, but are merely correlative points of view, which we find ourselves compelled to adopt in order to reduce our experience to order and system. This is Phenomenalism. As the phenomenal necessarily implies the real or noumenal, this doctrine logically leads to Agnosticism, i.e. the theory that, while there is some reality behind the phenomena of mind and matter, the limitations of our knowledge prevent us from giving it definition. Lastly, nature and man may be denied to have any separate reality, the view held being that they are either modes of God, or illusions that from the highest point of view disappear, leaving only the one absolute reality of God. Thus two forms of Monism arise, Pantheism and Mysticism. The former admits the reality of the finite as a determination of the infinite; the latter resolves all beings, human and non-human, into one all-comprehensive Being.

It will be observed that all these theories are agreed in assuming that reality must of necessity be a unity, the only question being in regard to the specific character of this unity. What we shall have to ask is whether any of them really secures the unity at which it aims. And first of all as to Naturalism, the theory which finds in nature itself a sufficient explanation of all the facts that fall within our experience, and therefore discards what it regards as the fiction of any reality, human or divine, which is not reducible to nature. Naturalism is perfectly aware that in life and consciousness we seem to have facts which cannot be explained on purely naturalistic principles, and that, granting the irreducibility of mind and matter, we seem compelled to maintain the existence of a God to serve as the unity comprehending both. But the separate and independent reality of mind and God are held to be incompatible with the assured results of science, which finds nothing in our experience that cannot be reduced to a mechanical system of mass-points that undergo transpositions in space. It must be carefully observed that Naturalism is entirely distinct from Science. A physicist, chemist or biologist may indeed hold that, for the attainment of his special object, namely, the mathematical or quantitative estimate of all phenomena, it is essential to regard all beings, whether inorganic, organic or self-conscious, from the point of view of mass and energy; but the scientific man as such does not maintain that the universe is completely explained when it is quantitatively determined. The peculiarity of Naturalism is that it converts the attitude of the scientific man, adopted as a convenient and practical method of solving his special problem, into the positive or dogmatic assertion that this attitude is ultimate, and therefore that nothing in the universe is real except the mechanical system of mass-points as undergoing certain reciprocal changes. For a consistent Naturalism the only God is this mechanical system, to which all the facts of life and mind are held to be reducible. It is this rigid and dogmatic system that we must now try to understand and estimate.

The first view of the world, as we have seen, is that which regards it as composed of an infinite number of separate things and events, the relations of which, as merely external, do not affect their independence and individuality. From this point of view, which is that of common sense, science starts, and, though the result of its investigations is to show that no concrete sensible thing is really permanent, it is loath to surrender its original presupposition, and therefore the scientific man is apt to maintain that, while sensible things are continually undergoing dissolution, the ultimate elements of which they are composed are eternal and unchangeable. What these ultimate elements are is not perfectly clear. The prevalent view is that all real objects, whether we distinguish them as inorganic or organic, and whether the latter do or do not imply consciousness, are actually made up of hard or incompressible atoms, arranged in varying configurations and in greater or less complexity. All the changes in the world must therefore be regarded as reducible to the movement of atoms, as resulting in a continual kaleidoscopic alteration in the manner in which they are grouped together. Thus is explained or described “the movements of the earth and the heavenly bodies, the seasons and the tides, the sun and the wind and the rain, the weathering of the mountains, the making of the fruitful land and so forth.”1 These processes may be regarded as “merely complicated cases of change of configuration in a system of mass particles.” The universe is thus conceived as constituted by ultimate elements, variously compounded and in incessant motion. Sometimes the changes of these elements are held to take the form of vibratory movements, at other times that of translation. Physical phenomena and chemical action, as well as other qualities of matter which are perceived by our senses—heat, sound, electricity, possibly even attraction—are supposed to be reducible to the elementary movements of the ether, the electron or the atom. Moreover, the matter of which organized bodies are composed, is held to be equally subject to the same laws: all the changes in the nervous system, e.g., being due to the attraction and repulsion of its molecules and atoms. The nervous system, it is said, suffers a series of shocks from surrounding bodies, and therefore the sensations, feelings and ideas which arise in consciousness may be defined as mechanical resultants; while the molecular movements of the nervous system lead either to reflex movements, or to so-called “voluntary actions,” which are at bottom of the same essential nature.

It may be doubted, however, whether this particular form of the atomic theory is more than a good “working conception.” How it is reached has already been indicated. Starting from the assumption of a world which is made up of a number of particular things, independent at once of one another and of the conscious subject which apprehends them, an attempt is made to explain how they come to be known. As actually perceived they seem to be distinguished from one another by the qualities they display, and therefore at first sight it seems impossible to understand how they can be equivalent to one another. For, not only do beings possessed of consciousness seem to differ in kind from those that are merely sensitive, and much more from those that are only capable of assimilation and growth; not only is there an apparently irreducible contrast between living and non-living beings; but even in the case of inorganic things, it seems at first sight impossible to reduce chemical and physical phenomena to a common denominator. This difficulty, however, is supposed to be overcome by ascribing the qualitative differences of things to the effect upon our senses of external things, which, as devoid of such qualities, are perfectly homogeneous. When we have got rid in this way of colour, heat, resistance and weight, the only characteristics of a thing that remain seem to be its extension, shape, position and mobility. But we can hardly stop even here; for shape still seems to be a definite and irreducible quality of particular things. Eliminating shape, nothing apparently is left but occupancy of space, mobility and fluidity. This is virtually the conclusion of the late Lord Kelvin, who conceived of matter as “a homogeneous and incompressible fluid in which vortices move, thus producing the properties of matter.” In this view of the universe it is still assumed that the physical world is independent of mind, and that it is possible to distinguish one mode of movement from another. Strictly speaking the last supposition is hardly consistent with the theory; for in a perfectly homogeneous fluid there is no separation of parts; nor can there be any distinction between one vortex-movement and another, since the movement of the perfectly homogeneous is the same thing as no movement. The reason, in fact, why it is supposed that one part of the fluid can be distinguished from another, and therefore that actual motion is conceivable, is that the changes in sensible objects arc assumed to have correspondent changes in matter as it is in itself. But this correspondence is simply taken on trust, and is due to the attribution of distinctions which in strictness hold only of things as presented to sense, not to the frictionless fluid which exists only for abstract thought. It will be understood that I have no intention of denying the value for science of the atomic theory, even in the sublimated form suggested by Lord Kelvin; what I wish to draw attention to is that, when it is put forward as a complete explanation of reality, it suffers from the fundamental defect of identifying an abstraction from reality with reality in its completeness. In a perfectly frictionless fluid we may assume whatever distinctions we please, but any distinction that is so made must be due to an arbitrary limit set up by our imagination in that which is declared to be in itself devoid of all limits because absolutely homogeneous. Fictions may aid us in calculating the movements of things, but it by no means follows that reality must correspond to them.

Whether the atomic theory of matter in either of its forms is accepted or not, and indeed even if no hypothesis as to the ultimate constitution of matter is advanced, there can be no doubt that the theorem of the conservation of energy is a correct formulation as far as it goes of the nature of all physical processes. On the axiom that all bodies, however they may differ in their sensible properties or dimensions, are subject to the same mechanical laws, rests the whole of our physical science, and, if naturalism is right, the only scientific view of the world. In any closed system the sum of the kinetic and potential energy is constant, being incapable either of increase or diminution. Potential energy is shown in a stone when it reaches the highest point of its path after being thrown straight up from the earth, and in the chemical energy stored up in a living body, while in the bob of a pendulum kinetic energy is converted into latent energy of position at each moment in which it occupies either of the extremities of its path. Dealing only with mass, or quantity of inertia, and energy, science finds within the order of physical facts uniformities which are absolutely rigid and inviolable. The movements of bodies are interdependent; and therefore the greater the mass, the less in any given case is the acceleration; the less the mass, the greater the acceleration. When therefore two masses come into dynamical relation to each other, two equal and opposite forces are involved—a force being defined as rate of change of momentum. When one form of energy is transformed into another, there is no change in the quantity of energy; and hence “the total sum of physical processes of the universe results in no change in the quantity of its physical energy”; so that “the sum total of the energy of the physical universe is a constant quantity, remaining without the least increase or diminution throughout all time.”2

Now, naturalism maintains that the doctrine of the conservation of energy is the fundamental law of all existence, and, therefore, embraces within its sweep, not only physical and chemical, but also organic and conscious processes. There is only one science of nature, it is said—that which interprets all things in purely mechanical terms. The assumption of common sense that there is in living beings, and much more in conscious beings, a reservoir of independent energy which can in anyway interfere with the total quantity of physical energy, is fatal to all science. To the principle of the conservation of energy there can be no possible exception; there is “not an atom, either in the nervous system, or in the whole universe, whose position is not determined by the sum of the mechanical actions, which the other atoms exert upon it. And the mathematician who knew the position of the molecules or atoms of a human organism at a given moment, as well as the position and motion of all the atoms in the universe capable of influencing it, could calculate with unfailing certainty the past, present and future actions of the person to whom this organism belongs, just as one predicts an astronomical phenomenon.” Granting the universality of the principle, this conclusion follows as a necessary inference; for we must then suppose that “the material points of which the universe is composed are subject solely to forces of attraction and repulsion, arising from these points themselves and possessing intensities which depend only on their distances; hence the relative positions of the material points at a given moment—whatever be their nature—would be strictly determined by what it was at the preceding moment.”3 The energy of the universe being a constant quantity, nothing can in the least degree influence the movement of any body but the impact upon it of another body; and therefore vital or mental influence is inconceivable, since it would increase or diminish the existing quantity of energy.

It is obvious from the nature of the method employed, which consists in abstracting from everything but mass and energy, that the result must be hypothetical in this sense, that it depends upon the legitimacy of the assumption that the presence of such concrete properties as density, cohesion, chemical affinity and vital phenomena in no way alters the validity of the conclusion. Whatever the other properties of a body may be, its mass and energy, it is held, may be determined independently. What the mechanical theory of the world proves, therefore, is that, however diverse in quality phenomena may be, the transformation of one form of energy into another in no way changes its total quantity. Energy in the form of mechanical work is precisely equivalent to so much energy in the way of heat or of radiant energy or of energy of the electric field. It must be observed, however, that the admission of quantitative equivalence does not necessarily imply that all forms of energy are at bottom mechanical. The doctrine of the conservation of energy means that there is constancy in the quantitative relations of physical processes, not that there are in these no qualitative differences. It is assumed by naturalism, however, that the whole process of evolution, including not only physical and chemical phenomena, but the origination and development of living and conscious beings, can be explained without reference to any other principle. This conclusion is an illegitimate extension of a principle which is undoubtedly valid within its own sphere. To say that the total quantity of energy in a closed system is constant, is quite compatible with any modification of the system which leaves that quantity intact. The principle of degradation of energy, for example, is perfectly consistent with the principle of conservation, expressing as it does the fact that there is a tendency in all physical changes to take the form of heat, and that heat tends to be distributed among bodies in a uniform manner. Thus the instability due to the great variety of qualitative changes which take place in our solar system is said to be gradually giving place to a monotonous repetition of elementary vibrations. This principle therefore concerns solely changes in the form of energy manifested, and in no way interferes with the quantity of energy, At the end of a long process, in which changes that are visible and heterogeneous are converted into changes that are invisible and homogeneous, it still remains true that the quantity of energy is neither increased nor diminished. On the other hand, the law will equally be preserved, if mechanical energy is transformed into its equivalent in thermal, chemical or vital energy. The doctrine of the conservation of energy tells us nothing in regard to the specific form assumed by the world. So far as it is concerned, the solar system might have begun with the greatest complexity, and in course of time have reverted to the greatest simplicity. From a purely mechanical point of view, there seems to be no reason why there should be any increase of complexity. We cannot by the law of conservation of energy, as Dr. Ward points out, tell whether an egg will be transformed into a chicken or into an omelette, because in either case the quantity of energy will be the same.4 The only change which is allowed for is change of motion—i.e. change in the grouping of elements that are unchanged, because they are assumed to be entirely destitute of qualitative diversity. Whether there is stagnation, development or degradation, the law of conservation of energy will hold good, since all that it demands is such a rearrangement of masses in space and time as leaves the total quantity of energy unaffected. It is thus evident that any real process of evolution can only be defended upon grounds that lie beyond that law. This does not mean that the principle of conservation of energy is in any sense doubtful, but only that it is an incomplete determination of the universe. It is true that chemical, vital and conscious phenomena presuppose mass and energy; but the attempt to express these phenomena purely in such terms involves a confusion of ideas. On the mechanical level there is neither life nor mind, because all that is characteristic of them has been eliminated for purposes of research; and therefore, if we are really to characterize life and mind as they are, we must first restore what has been set aside, and seek for conceptions adequate to the new facts. One reason why this obvious truth has been overlooked is the confusion between analysis and abstraction. When the chemist is seeking to determine the constituent elements of a substance, he must abstract from all the other characteristics found in it and concentrate his attention entirely upon the chemical changes it is found to undergo. The result is to break up the whole into its elements—a process which is at once an analysis and a synthesis; for, in discovering the elements that will combine into a whole, the chemist at once distinguishes the elements from one another and combines them into a unity. Similarly the physicist determines the special sphere of his investigation by abstracting from all that is irrelevant for his purpose, which is to discover the laws of motion; and, confining himself within this sphere, he is able to show that the elements of mass, space and time are essential to the mechanical changes of bodies, and thus he is able to advance by synthesis to the laws of motion. It is therefore evident that analysis and synthesis, in each of the special sciences, always proceed on a basis of abstraction. From the point of view of mechanics we cannot by synthesis go beyond the elements determined for us by our primary abstraction, just as in chemistry no combination of elements will yield any solution of the problem of biology. The attempt to explain the facts of life in mechanical terms is therefore foredoomed to failure; and with this failure the whole foundation of naturalism crumbles away.

From what has been said it is evident that there is no real ground for asserting that the principle of conservation of energy is an adequate formulation of all modes of existence. It is therefore a mistake to assume that whatever refuses to be compressed within its framework cannot be true in any absolute sense, but must arise from the limitation of our experience. There is no reason to suppose that any expansion of knowledge would ever bring life and consciousness under this rule. We must therefore come to the study of these free from the gratuitous assumption that they can be explained on the principle of conservation of energy. It is certainly true that a rational system cannot be one that is given up to chance; law there must be; but it does not follow that this law must be limited to the formulation of the conditions of a quantitative system. It is therefore of great importance to determine whether the facts of our experience do or do not compel us to employ a higher conception than that of conservation of energy when we are dealing with life and mind. If not, we must be prepared to view the universe as by its very constitution excluding even the possibility of freedom, and ruling out in advance, as a hypothesis not only unverifiable but self-contradictory, the whole conception of the world as the manifestation of a divine principle. Such a conclusion is not one to be lightly accepted. The moral and religious consciousness alike revolt from a theory which, in Goethe's words, “reduces that which appears higher than nature, or rather as the higher in nature itself, to a useless and formless matter and motion.” This mechanical philosophy, he says in the Dichtung and Wahrheit, “appeared to us so grey, so Cimmerian and so dead that we shuddered at it as at a ghost. We thought it the very quintessence of old age. All was to be necessary, and therefore no God. Why, we asked, should not a necessity for God find its place among other necessities? We confessed, indeed, that we could not withdraw ourselves from the necessary influences of day and night, of the seasons, of the climatic changes of physical and animal conditions; yet we felt something within us that appeared arbitrarily to assert itself against all this; and again something which sought to counterpoise such arbitrariness and to restore the equilibrium of life.”5 The poets of the nineteenth century, indeed, are unanimous in rejecting the cold dead identity of a universe without process and without life. Tennyson formulates and passionately protests against it:

“The stars,” she whispers, “blindly run;

A web is wov'n across the sky:

From out waste places comes a cry,

And murmurs from the dying sun;

“And all the phantom, Nature, stands,—

With all the music in her tone,

A hollow echo of my own,—

A hollow form with empty hands.

“And shall I take a thing so blind,

Embrace her as my natural good;

Or crush her, like a vice of blood,

Upon the threshold of the mind?

And, in another passage:

“Are God and Nature then at strife,

That Nature lénds such evil dreams?

So careful of the type she seems,

So careless of the single life.

“So careful of the type? but no,

From scarfed cliff and quarried stone,

She cries ‘a thousand types are gone;

I care for nothing, all shall go.

“Thou makest thine appeal to me:

I bring to life, I bring to death:

The spirit does but mean the breath:

I know no more.’ And he, shall he,

“Man, her last work, who seem'd so fair,

Such splendid purpose in his eyes,

Who roll'd the psalm to wintry skies,

Who built him groves of fruitless prayer;

“Who loved, who suffer'd countless ills,

Who battled for the True, the Just,

Be blown about the desert dust,

Or seal'd within the iron hills?

Such a conclusion he rejects, declaring that

“like a man in wrath the heart

Stood up and answered, ‘I have felt’”

in other words, that all our higher aspirations contradict the creed of naturalism. It is not enough, however, simply to appeal to feeling; and we must therefore ask whether an impartial examination of the facts of experience compels us to regard the mechanical conception of the world as the last word of reason.

In support of the conclusion that there is no generic distinction between organic and inorganic things various arguments are advanced, which in their cumulative force are held to reach at least the highest degree of probability.

An appeal is made to the fact that many chemical compounds, formerly supposed to be peculiar tot the living body, have been produced in the laboratory by artificial synthesis. Not only so, but chemistry has even produced what looks like certain facts of organization, such as the movement of protoplasm, and even the movement of the amoeba and the infusorian. It is also admitted that there are certain laws which are common to living and non-living beings. Moreover, irritability, which was wont to be regarded as peculiar to living matter, has been ascribed to the liberation of the potential energy stored up in the organism. It is also argued, from the fact that crystals restore themselves to their normal form when injured, that the adaptation of an organism to changed conditions—as displayed, for example, in the regeneration of lost organs–is at bottom a mechanical process. And, lastly, it is maintained that there is a series of connecting links between inorganic matter and the elementary cells out of which all organisms are built up.

To all such attempts to level down the organic to the inorganic, the general objection applies, that it confuses the proposition, that there are no living processes without mechanism, with the very different proposition, that living processes are nothing but mechanism. It is the former proposition that gives to Naturalism its plausibility; while it is the latter which it supposes itself to make good. So far as it is a protest against the assumption of a separate and independent principle of life, which is complete in itself apart from mechanism, Naturalism contains an element of truth of the utmost importance. Such an assumption leads to the fiction of a soul which is only externally attached to the body, and therefore, by an inevitable logic, to the doctrine of metempsychosis. Of any independent principle of life we have no experience, nor can it be legitimately deduced from experience. All life as known to us is inseparable from the mechanical system of which it constitutes the principle, and to separate it from its conditions is to convert it into an abstraction. But, while Naturalism escapes from the absurdity of maintaining the independent reality of a “vital principle,” it falls into the still more disastrous fallacy of identifying one aspect of the total process of life with the whole. It is at bottom the same fallacy as leads the vitalist to affirm the existence of life in its isolation which acts upon the mind of the naturalist when he affirms the independent reality of mechanism. Both views are abstract and one-sided. There is no life apart from body, and yet life is not body, but the principle which determines its specific character. The mechanical system expresses that constancy in the system of energies by which the world is characterized, while the principle of life is the informing principle without which that system would have no meaning, and indeed could not even exist. We may, therefore, be certain that the attempt to reduce life to physical or chemical processes must rest upon an inadequate and untenable conception of the real world.

(1) It is argued that, as compounds formed by the living organism have also been produced artificially, these cannot demand a peculiar vital principle for their production. Scientific men, however, are by no means agreed in their interpretation of such facts. Leading chemists like Cope point out that the only organic compounds artificially produced are waste products, while the peculiarly active plastic substances such as result from the assimilation of inorganic substances, have never been constructed artificially.6 The appearance of vital activity, again, proves nothing so long as protoplasm cannot be artificially produced; while even the humblest manifestation of life, as in the infusorian, and still more in the amoeba, do not admit of physical or chemical explanation. The truth is that the deeper the study of the facts of life, the more inadequate seems every attempt to explain them by physics or chemistry. “The study of the cell,” says an eminent histologist, Mr. G. B. Wilson, “has on the whole seemed to widen rather than to narrow the enormous gap that separates even the lowest forms of life from the inorganic world.”7

(2) The argument that the chemical processes which go on in non-living beings are of the same nature as those present in living beings obviously does not prove what it is supposed to prove. The fallacy here is a special instance of that tendency to isolate and hypostatize one aspect of the whole, against which we have to be continually on our guard. Living processes cannot be reduced to physical or chemical processes, though the latter are the necessary Presupposition of the former. When therefore abstraction is made from what is characteristic of life, no difference between living and non-living beings can possibly be found. But the presence in the living body of the same physical and chemical laws as those that are found in other bodies by no means proves that all bodies are the same in their fundamental nature. An organism is not a mere aggregate of parts, subject to the law that the changes which the parts undergo leave them essentially unchanged; on the contrary, its parts are complementary of one another, so that the functions of the living being are interdependent, and its changes bring into existence what previously had no reality. Nothing like this is found in the inorganic world. Astronomical, physical and chemical facts form part of an unchanging system, whereas a living being is continuously generating itself from moment to moment. No doubt life involves mechanism, but this mechanism is no independent reality; it is merely the artificial isolation of what actually obtains only within a whole. As M. Bergson says, “life is no more made up of physico-chemical elements than a curve is composed of straight lines.”8

Hence (3) when it is said that irritability may he nothing but the liberation of potential energy, it is overlooked that the energy so liberated would not be stored up in the organism, or liberated at a given moment, but for the distinctive processes of the organism. The vegetable “derives directly from the air and water and soil the elements necessary to maintain life, especially carbon and nitrogen,” while the animal assimilates these elements after they have been fixed for it in organic substances by plants, or by animals which directly or indirectly owe them to plants; but the process of assimilation in either case is distinctive of living beings, and is never found in inorganic things. It is characteristic of animals, as distinguished from plants, that they have the power of employing the nervous mechanism, or what corresponds to it in the lower forms of life, for the conversion of the energy stored up into movements from place to place.

(4) From what has been said it is evident that the assimilation of a living organism to a crystal is fallacious. The crystal has neither differences of parts nor diversity of functions, and therefore it can lay no claim to individuality; whereas the whole process of life is in the direction of individuality. It is true that complete individuality is not realized even in man; nevertheless all forms of life, even the lowest, exhibit a persistent tendency towards individuality. The most we can say of the crystal is that it displays a power of self-restoration which is analogous to the regeneration of lost organs characteristic of living beings; nevertheless, the fundamental difference remains, that the living being is composed of organs which are mutually dependent and perform diverse functions, and that its self-restoration is essentially a process by which new organs are created and its tendency to individuality maintained and developed.

(5) Nor can it be fairly argued that, because a series of intermediate forms may be interposed between inorganic things and the living cell, we can therefore reduce life to mechanism. Why should we not rather conclude that in organisms there is to be found explicitly realized that which in inorganic things is only a promise and a prophecy? In truth, however, what the facts prove is neither the reduction of the organic to the inorganic, nor the elevation of the inorganic to the rank of the organic, but simply that in all its forms nature is striving towards complete individuality. Notwithstanding the analogy of the inorganic to the organic, I do not think that we can regard the former as in essence identical with the latter; much less can we degrade the latter to the level of the former. Life is an absolute beginning in this sense, that no amount of complication of the inorganic will produce it. Nor can we say, because the crystal and the animal both undergo a process of restoration, that they are therefore identical in essence; to reason in this way is to follow the fallacious argument by which Fluellen proves King Henry the Fifth to be a hero like Alexander the Great, because he was born in Wales, and there is a river in Wales as well as in Macedon.9 No doubt if it could be shown that inorganic things have developed into living beings, we should then have to conclude that the former are in essence identical with the latter; but, until that proof is supplied, we must hold that the self-restorative process of living organisms differs in kind from the process by which a crystal restores its lost parts.

These considerations seem to make it clear that by no possibility can life be explained upon purely mechanical principles. It may be said, however, that this conclusion is rendered doubtful or even incredible when we take into consideration the process of biological evolution, which is apparently inconsistent with any generic distinction between the living and non-living. It will therefore be advisable to consider the two dominant theories in regard to the development of living forms, which may be called in a general sense the Darwinian and the Lamarckian: the former favouring a purely mechanical explanation; the latter maintaining a certain purposive tendency. Naturalism, believing as it does that all the facts of our experience are explicable on a purely mechanical basis, inevitably gravitates towards the former and rejects the latter.

Darwinism, as we know, denies the older biological doctrine, which maintained that living beings can be divided up into distinct species, each of which has an independent origin. It is no doubt true that all living beings may be arranged in classes from a comparison of their peculiarities of form, size, colour, etc.; but the classes so formed, it is argued, cannot be identified with natural species. For species are not immutable, as this theory would imply, since living beings belonging to what are called the same genera are lineal descendants of some other and generally extinct species, just as the acknowledged varieties of any one species are the descendants of that species. In the “struggle for existence,” those survive which are best adapted to the environment; and, by the accumulation of slight increments of favourable differences, the immense variety of living beings that cover the earth are gradually developed from the one or more primordial forms that we may hypothetically assume to have been their original progenitors. Thus natural selection, operating upon accidental variations, which are transmitted by heredity, is held to be the main, if not the exclusive, factor in the evolution of organic forms.

The strict Darwinian theory, then, would explain the development of living beings on the principle that, in the struggle for existence, only those representatives of the species which happen to possess some favourable characteristic are able to survive and to leave descendants. According to this view, the outer conditions do not exert a positive influence upon the being, but merely eliminate beings not provided with the advantageous feature. A plant that happens to be well-supplied with spines or hairs may escape destruction, while another less favourably endowed perishes. Why a plant should have such an advantageous feature we cannot tell. The theory therefore is that the variations by which the development of organic forms is explained are purely accidental, and are, moreover, of a very slight character. No doubt sudden variations do occur, but these, it is held, are not perpetuated. The genesis of species is therefore to be accounted for by an accumulation of insensible variations.

This is a simple and clear form of the doctrine; but, just because of its simplicity and clearness, it seems to be open to insuperable difficulties. These no one has pointed out with more convincing force than M. Bergson, in his brilliant book on “Creative Evolution.” We are told he says, that every organic structure is the result of the slow and gradual accumulation of very small differences. Let us, then, take such a complex structure as the human eye, and compare it with the eye of a mollusc like the common pecten. While it is held that vertebrates and molluscs may be traced back to a common ancestor, they yet must have separated and developed on divergent lines long before there was any appearance of an eye. How then is the remarkable similarity between the eye of the vertebrate and the eye of the mollusc to be explained? We must suppose that it is due to the accidental occurrence of variations which have been produced by an almost infinite number of infinitesimal causes. Moreover, as the eye is composed of thousands of different cells, each of which is itself a kind of organism, we are confronted with the extreme improbability of the vertebrate and the mollusc changing point by point, and finally, under the influence of entirely different causes, developing a structure the essential parts of which are the same in both. For, we must remember that the different parts of an organism must be co-ordinated, or the variation will be of no advantage. We have therefore to suppose that every part of the organ simultaneously develops correlated variations; so that, not only does variation arise accidentally, but, equally accidentally, there emerge a number of correlated variations; and these, on the hypothesis, must arise accidentally in two entirely independent lines of evolution.

It thus seems incredible that two independent and yet closely resembling structures can have arisen in the manner required by the hypothesis of accidental but insensible variations. There is no reason why we should deny that the eye of the vertebrate and the eye of the mollusc have developed by the gradual accumulation of slight increments of difference, so long as we admit the principle of correlation—a principle, indeed, which Darwin accepted; but to admit correlation is virtually to deny evolution by the purely accidental appearance of variations. All that the theory really shows is that the evolution of organized beings takes place, as a rule, by the gradual accumulation of slight differences; it gives no explanation of the appearance of such differences, much less of the appearance of correlated differences; and therefore, to obtain such an explanation, we must have recourse to an entirely different method. For the mechanical form of the doctrine of evolution, in other words, must be substituted the organic.

An attempt, however, has been made to evade this conclusion by maintaining, in contrast to Darwin's theory of insensible variations, that, while variations are accidental, they occur suddenly and simultaneously, so that a new species comes into being not gradually but all at once. This form of the doctrine cannot be regarded as satisfactory; for, while it rightly recognizes that the parts of an organ must be co-ordinated, it makes this fact incredible by ascribing the simultaneous variation to accident. It is hard to believe that by accident sudden variations should occur along two independent lines of development. Here again, therefore, we are forced to fall back upon a principle different from that of mechanism.

These two forms of evolution seek to account for the development of organisms on the principle of accidental variations in the living being itself. There is, however, a third form of the mechanical hypothesis: that which attributes the variations to the direct influence of outer circumstances. In this case the resemblance in structure between the eye of the vertebrate and of the mollusc is held to be due to the action of light upon two different organized forms, the result being a similar change in the structure of both. Now, it must be observed that on this view the organism is supposed to be adapted to the apprehension of light by the influence of light upon it. The eye does not first exist as an eye, and is then modified by the influence of light, but it is supposed to be developed by the direct action of light itself. In the lower organisms, it is said, there is only a pigment spot, which we may well suppose to have been produced by the action of light, and by a gradual process this simple spot develops into a complicated eye. But the real question is, whether light alone could ever have developed an organ capable of using it. The eye in vertebrates is connected with a nervous, muscular, and osseous system; and it will hardly be maintained that these have been formed by the influence of light. Thus we must ascribe the formation of the eye and all that is connected with it to a power different from light, the power of building up a complicated structure which turns to account the excitation that light produces. Moreover, the process of development of the eye in the case of vertebrates is quite different from that of molluscs; in the former, the retina is an expansion in the rudimentary brain of the embryo, in the latter it is directly derived, It is therefore impossible to explain these two distinct evolutionary processes without having recourse to some inner principle other than that of mechanism, by which the same effect is obtained by entirely different means. And thus we are inevitably led to consider whether the Lamarckian theory may not give a truer account of the evolution of living beings.

On this theory living beings are regarded as displaying a certain selective activity, so that the variation which results in the formation of a new species is not due merely to accident, but results from the effort of the being to adapt itself to the environment; while the modified structure acquired by the use or disuse of its organs is transmitted to descendants.

There seems to be a certain ambiguity in regard to the meaning to be attached to the term “effort,” by which evolution is on this view sought to be explained. It is undoubtedly true that an organ may be strengthened and enlarged by use; but something more than this is needed to explain the evolution of a complicated structure like the eye of the vertebrate or the mollusc. Before the Lamarckian doctrine can be accepted, we must also be prepared to admit, what biologists like Weismann deny, that acquired characters can be transmitted. Weismann maintains that development is entirely determined by the constitution of the germinal cells, which he regards as practically independent of the somatic cells, so that the only characters transmitted are those which are already found in the germinal cells. Acquired characters are generally habits or the effects of habit, and it is argued that, as all habits rest upon a natural aptitude, it is this natural aptitude which is transmitted, not the acquired character resulting from its repeated exercise. The influence of alcoholism on descendants is not an instance of the transmission of acquired characters, because here both soma and plasma have suffered from the action of the same cause. It is then at least doubtful whether the Lamarckian theory of the transmission of acquired characters can be accepted. In any case, such transmission is more or less exceptional, and therefore it is highly improbable that it can account for the enormous number of variations, all in the same direction, that we must suppose to have effected the transition from the pigment spot of the infusorian to the eye of the mollusc and of the vertebrate.

Neither the neo-Darwinian nor the neo-Lamarckian theory, then, can be regarded as a complete and adequate explanation of the process by which species have originated, though both have fixed upon different elements involved in that process. The former is probably right in affirming that we must look to the differences inherent in the germ borne by the individual for the essential causes of variation. On the other hand, the fundamental defect of this mode of explanation is its assumption that these differences are entirely fortuitous. Eimer is probably right in claiming that variations continue in definite directions from generation to generation, though his claim to account for the development of the most complicated organic structures by purely physical and chemical causes is obviously untenable. The neo-Lamarckian reference of evolution to selective activity, again, has undoubtedly a solid basis of truth behind it; but it is a mistake to regard this activity as dependent upon the more or less conscious effort of the individual. The effort which produces such a profound transformation of primitive forms as that which results in the formation of a complicated structure like the eye can only be attributed to something in the fundamental nature of the universe. This organizing principle must be conceived, not as an abstraction, formed by simply generalizing the common characteristics of all living beings, but as a principle constituting their essential nature. The process of evolution we must therefore conceive as the realization in millions of individuals of the same identical and self-differentiating principle of life, a principle which realizes itself by subduing the physical and chemical forces of the universe to itself and using them as its instruments. The development of organic structures cannot be the result of an infinite number of accidental variations, accidentally working in a certain direction, and accidentally resulting in the formation of an infinite variety of species; it must be the self-differentiation of a single eternal and inexhaustible principle.

It is usually supposed that with the rejection of all purely mechanical explanations of evolution we are compelled to admit that only by a teleological conception of organized beings can we make them intelligible to ourselves. M. Bergson, however, in this following the lead of Kant, who regarded the idea of purposiveness as merely subjective and regulative, rejects finalism as decidedly as mechanism.

His main objection to it seems to be, that it does not allow for that “creative evolution” which he regards as the fundamental principle of the universe. In the extreme form in which finalism is maintained by Leibnitz it is held that all real beings are living, and in the beginning already contain “preformed” all that is subsequently evolved. This view, M. Bergson contends, is merely an inverted mechanism and allows of no real evolution, all that presents itself in the subsequent history of individuals being presupposed to begin with. There is no real succession, change or transition, time being nothing but a confused perception, which would vanish away if only we were capable of seeing things as they truly are. Not only, however, does he hold that we must reject this form of finalism, but M. Bergson will not accept even that internal or immanent finality, which maintains that “each being is made for itself,” and that “all its parts conspire for the greatest good of the whole and are intelligently organized in view of that end.”10 We cannot, indeed, on this view, say that the universe has any single end “to which the whole creation moves,” or that different beings have been made for each other. Nature, it is said, presents disorder alongside of order, and it is a very shallow view which affirms that grass was made for the cow or the lamb for the wolf; but, taking each organism separately, the division of labour and co-operation of all the parts are inexplicable apart from the principle of immanent purpose. Now, the assumption here made, argues M. Bergson, is that finality is purely internal; which again implies that each living being is a complete individual. But purely internal finality is nowhere to be found. An organism is composed of tissues, and the tissues of cells; and both tissues and cells have as much right to be called individuals as the whole organism When therefore it is said that the elements which comprise the organism all contribute to its life, we virtually fall back on the principle of external finality, which we have denied of the universe as a whole. There is no internal “vital principle,” says M. Bergson, peculiar to each individual, since no real individual can anywhere be found. All living beings are connected directly or indirectly with all others, and therefore the attempt to defend finality by restricting it to separate individuals is foredoomed to failure. “If there is finality in the world of life, it includes the whole of life in a single indivisible embrace.”11 Why, then, does the idea of immanent teleology seem so conclusive? The reason, M. Bergson answers, is that our intellect is “cast in the mould of action.” In order to act, we make a plan, and this plan we are able to realize only if there is a fixed connection between means and ends. When therefore we employ the intellect speculatively, we not unnaturally make use of the mode of conception with which we are familiar in practical life, and therefore we come to think of an organism as realizing by the co-operation of its parts a preconceived end. But this anthropomorphic mode of conception is inadmissible. In truth finalism is open to the same objection as mechanism, namely, that in assuming absolute fixity in the end and in the means by which it is reached, it allows of no real evolution, but only of the apparent evolution of that which is already unalterably involved in the original constitution of things.

M. Bergson therefore holds that the true explanation must be found in a principle which transcends both mechanism and finalism. Reality, he contends, is never the repetition of that which already exists, but the “ceaseless upspringing of something new.”12 Hence we cannot tell beforehand what path life will take. How, then, can it be said that the end towards which life moves is predetermined? Which life moves is predetermined? To think of the matter in this way is, he argues the development of life to the labour of a workman, who gathers together a number of separate things and arranges them in imitation of a model. But this is not how nature works; it does not bring together a number of preexistent elements according to a pre-conceived plan; it is we who divide up the organism into a number of elements, which we then conceive to be externally put together to form a whole. In reality an organism is no compound of separate elements, either coming together accidentally, or brought together purposively. To organize is not the same thing as to manufacture. The former works from the centre to the periphery, the latter from the periphery to the centre. A machine displays all the parts that have been externally combined, whereas an organism is the creation by dissociation and division of new elements. Life is “a tendency to act on inert matter,” but “the direction of this action is not predetermined, hence the unforeseeable variety of forms which life, in evolving, sows along its path.” There is always involved “at least a rudiment of choice,” and “a choice involves the anticipatory idea of several possible actions.” Evolution is not the realization of a plan, but “a creation that goes on for ever in virtue of an initial movement.” The unity of the organized world is “a prolific unity of an infinite richness.”13

  • 1.

    J. Arthur Thomson in Hibbert Journal, X. i. 111.

  • 2.

    M'Dougall, Body and Mind, p. 91.

  • 3.

    H. Bergson, “Les donées immediates de la conscience,” 110, 111; tr. Time and Free Will, pp. 144-5.

  • 4.

    J. Ward, Naturalism and Agnosticism, i. 229.

  • 5.

    Quoted in E. Caird's Essays in Literature and Philosophy, 1st ed., i. 74.

  • 6.

    Cope, The Primary Factors of Organic Evolution, Chicago, 1896, pp. 478-484.

  • 7.

    G. B. Wilson, The Cell in Development and Inheritance, New York, 1897, p. 330.

  • 8.

    Bergson, L'Évolution créatrice, p. 34; tr. p. 31.

  • 9.

    King Henry V., Act IV. sc. vii.

  • 10.

    H. Begson, L'Évolution Créatrice, p. 44; tr. p. 41.

  • 11.

    H. Begson, L'Évolution Créatrice, p. 47; tr. p. 43.

  • 12.

    H. Begson, L'Évolution Créatrice, p. 50; tr. p. 47.

  • 13.

    H. Begson, L'Évolution Créatrice, pp. 100, 105, 114; tr. 92, 96, 104-5.