§ 1. Animate Nature Abounds in Adaptations. § 2. Their Origin neither by Design nor Mechanical. § 3. Is There Purpose in the Inorganic Domain? § 4. Purposefulness and Purposiveness in Human Behaviour. § 5. Purposiveness and Purposefulness in Animal Behaviour. § 6. The Purposelikeness of the Ordinary Functioning of the Body is Covered by the Concept of Adaptation. § 7. Provisional Conclusion and Anticipation.
OUR survey of the Realm of Organisms as it is. affords evidence in support of the following propositions: (1) that living creatures are individualities standing apart from things in general and not exhaustively described in mechanistic terms; (2) that their lives abound in behaviour with a psychical aspect; (3) that there is in Animate Nature a prevalence of orderly systematisation, balance, and smooth working; (4) that there is a pervasive beauty both hidden and revealed; and (5) that a very large proportion of the time and energy at the disposal of organisms is devoted to activities which make not for self-maintenance and self-aggrandisement, but for the continuance and welfare of the race. In fact, we find in Animate Nature far-reaching correspondence to the ideals of the True, the Beautiful, and the Goodcorrespondences which may suggest to some a possible line of development for Natural Theology.
§ 1. Animate Nature Abounds in Adaptations.
A survey of the realm of organisms affords another great impression and that is the prevalence of adaptations. The narrowest hinge in my hand puts to scorn all machinery; the hand as a whole is the subject of a Bridgewater Treatise. The Vertebrate eye is extraordinarily well adapted, in spite of the instrumental imperfections which Helmholtz discovered. The functional correlations of internal organs such as heart and lungs are as effective as they are delicate. The flat-fish is so adaptable in its coloration to the pattern of the sea-floor on which it rests that it has practically a Gyges ring, making itself invisible, sometimes almost instantaneously. Flowers and their welcome insect-visitors are suited to one another as glove to hand. The realm of organisms abounds in adaptations, some extraordinarily perfect, some in process of becoming perfect.
First there are the structural adaptations of the organismsome with internal and some with external reference, some static, some dynamic. The internal structure of a long bone or of the stem of a plant is suited in detail to stand the strains and stresses to which it is exposed. The same quality of architectural stability may be seen everywhere from the scaffolding of a siliceous sponge like Venus's Flower Basket to the spine of a sea-urchin, from the spirally twisted encasement of an arenaceous Foraminifer to the prismatic structure of the enamel of our teeth.
Less static are the adaptations of parts that move and work. The adaptations of a bird's skeleton for flight and for bipedal progression are many and thorough. The heart is a masterpiece of fitness, and in many cases, as in the antelope on the plains or in the ptarmigan on the high mountains, there are interesting special adaptations of the heart to stand special strain. The delicacy and complexity of the mouth-parts of such insects as mosquitoes may well evoke the artificer's admiration.
Of great interest are the co-ordinating functional adjustments which secure smooth working. A fine example is the heat-regulating arrangement or thermotaxis of birds and mammals, which adjusts the production of animal heat so as to meet the loss. Superimposed on this, as it were, are the special adjustments which bring about winter-sleep in hibernating mammals. And there is no internal regulation more worthy of our admiration than the manner in which the mother-mammal is functionally prepared for the antenatal development of the offspring and its nurture after birth. The adaptive regulatory rôle of the internal secretions is one of the most fascinating chapters in modern physiology.
Inexhaustible, again, are the illustrations of the manner in which living creatures are adapted to the particular conditions of their life. The mole, living underground, is adapted in its short vertical fur and in the absence of an ear-trumpet to the reduction of friction in burrowing; its hand has become an extraordinary shovel and its shoulder-girdle and associated musculature are powerfully developed; the minute, imperfectly developed eye is good enough for what is required of it, and it is hidden by hair so that it does not get rubbed and become a source of weakness; and so the zoologist goes on.
We may also refer to the theoretically very interesting inter-organismal adaptations. These may be between organisms of the same kind, between parent and offspring, between male and female. Even the male parent may be adapted to the offspring as we see in the pouch of the sea-horse, and in the still more striking case of the New Guinea fresh-water fish called Kurtus, where a hooked bony process grows from the top of the male's head at the breeding season and serves for the suspension of the bunch of eggs. The young marsupials are born prematurely and cannot even suck; the mother places them in her external pocket of skin and has a special arrangement for forcing the milk into their mouth. They meet this, so to speak, with a special adaptation that prevents the milk going down the wrong way.
There are also inter-organismal adaptations between creatures of different kinds, of which the crowning examples are to be found in the way certain flowers and certain insects are suited for making the best of one another. Very striking also are the numerous mutually helpful associations which have been establishedpartnerships, commensalism, and symbiosis, in which there is sometimes two-sided adaptation. The case is repulsive, but the parasite is often adapted to its drifting life of ease and to making much of its host, which, in turn, is often adapted so that it hardly suffers at all from its guest. In the mimetic resemblance of one creature to another there is again adaptation, often of almost incredible subtlety.
In Indo-Pacific crabs of the genus Melia a delicate sea-anemone is often carried on the forceps, and probably serves to paralyse the crab's prey with its batteries of stinging cells. It is quaintly suggestive of a tool, and its occasional absence shows that it is not vitally necessary. But the partnership or commensalism is probably of very old standing, since the denticles of the forceps are elongated into needles which are adaptively suited to keeping a firm grip of the tool.
We are accustomed to the idea of adaptations, but perhaps we are not sufficiently appreciative of their nicety. When winter sets in, the North American ruffed grouse puts on snow-shoesa row of projecting plates on each side of each toe so that the bird can tread on the loose snow without sinking in. The African egg-eating snake, Dasypeltis, has very few teeth and it would not be profitable to crack the eggs in its mouth; the egg slips intact into the gullet, where it is met by the sharp points of the inferior spines of a number of vertebræ. These project into the gullet and cut the egg-shells, so that none of the precious food is wasted. The spines are said to be actually tipped with enamel, the hardest of all tissues. The empty broken egg-shells are always returned.
An adaptation that gives us pause is the egg-tooth found at the tip of the bill in many young birds, and used by them to break a way through the imprisoning egg-shell. It is a hard thickening of horn and lime at the tip of the bill, and since it develops before the horny ensheathment of the beak it may be a residue of a very ancient scaly armature in Reptilian ancestors of birds. Be this as it may, the instrument is an effective one and it is used only once! What happens is this: the young bird ready to be hatched thrusts its beak into the air-chamber that forms at the broad end of the egg; air rushes down the nostrils and fills the lungs for the first time; in the exhilaration of this first breath the unhatched bird knocks vigorously at the shell and breaks open the prison doors. After a few days, in most cases, the egg-tooth, having done its work, falls off,a well-adapted instrument that functions only once.
But there is a further detail which is of much interest. The bill and its egg-tooth are only the instruments; what about the musculature which works these? Prof. Franz Keibel has inquired into this in the case of the unhatched chick and duckling. He finds that the work is done by a muscle called the musculus complexus, and that this is very markedly hypertrophied for some time before hatching. On the tenth day after hatching, it shows no peculiarity. Here, then, we have a simple instance of the way in which development proceeds as if it were working with a purpose. How comes that musculus complexus to be temporarily exaggerated in strength, in relation to the breaking of the eggshell,an action which only occurs once in each generation?
The idea of adaptation is sometimes held far too narrowly, and a needless difficulty is made over the fact that some specific characters are not known to be adaptive to any particular condition of life. But, in the first place, some characters supposed at first to be quite indifferent have been shown, after closer acquaintance with the creature, to be finely adaptive. And, in the second place, an organism is not a system of pegs on which a hundred characters are hung, it is a harmonious unity, viable and persisting in virtue of its subtle internal equilibrium as well as in virtue of the adjustment of its tout ensemble to the conditions of life. Adaptation may have an internal as well as an external reference.
Beyond particular instances of organismal adaptation, we have the broad fact that in a given association of organisms a balanced modus vivendi is arrived at, a compromise between competing interests, so that the system persists and works smoothly. The balance of nature is the largest of all adaptations. Just as the Systema Naturæ of the taxonomistthe orderly classification of the classifierspeaks of rationality; so the vital systema naturæ which the naturalist discloses is also a cosmos. There is a systematisation or co-ordination of lives, world-wide in its scope, and becoming ever more subtle in its accomplishment.
§ 2. Their Origin neither by Design nor Mechanical.
Opposite the title-page of Darwin's Origin of Species, there is a quotation from one of the Bridgewater Treatises. A judicious quotation it is, but, as Professor Lovejoy points out, there is a historic irony in finding it at the outset of a book which was the death-sentence of the kind of argument most characteristic of the treatises in question. Darwin sought to show that, if copious variability be granted and abundance of time be allowed, then Nature's siftingthe process of Natural Selectionwill account for all the striking adaptations from which many thoughtful observers had been wont to argue directly to theism. He says himself: The old argument from design in nature which once seemed to me so conclusive, fails, now that the law of natural selection has been discovered. We can no longer argue that, for instance, the beautiful hinge of a bivalve shell must have been made by an intelligent being, like the hinge of a door by man. There seems to be no more design in the variability of organic beings, and in the action of natural selection, than in the course which the wind blows.
Now we cannot return to any crude form of the old idea that the thousand and one adaptations of organisms, which gratify our sense of fitness, are the direct outcome of the design of a divine artificer. It is agreed that they have been more or less gradually evolved by the operation of natural factors. They have been wrought out in what is often called Nature's workshop.
On the other hand, we cannot accept Darwin's statement that the evolution of adaptations is comparable to the work of the wind among the snow-drifts. The inadequacy of the statement is fourfold.
(1) The raw materials of adaptations are variations or mutationsthe precious idiosyncrasies of structure and function that are continually cropping up, that keep the realm of organisms on the move. Some of these variations may be accidental and some necessitated, but of many, especially those which may be called new departures, all we can say is that they arise,apparently from within the arcana of the germ-cells. They look like expressions of inherent creative spontaneity, like experiments in self-expression. And it must be remembered that a germ-cell is not an ordinary cell, but a condensed implicit individuality, rich in the gains of the past, rich in possibilities for the future,a psycho-physical being telescoped down. In any case, while our ignorance of the origin of variations remains, as in Darwin's day, profound, there is no reason why the argumentum ad ignorantiam should favour mechanistic interpretation. The fact is that we cannot at present give a mechanical account of the origin of the crop of variations from which Nature's weeding removes the tares. We always reckon without our host in Biology when we leave life out.
(2) An important idea, which we cannot at present elaborate, is that the variations or new departures which take hold must not be inconsistent with the already established organic architecture. Just as the architect or the crystal must build congruently, so the varying organism must not contradict itself. The novelty must be in keeping or harmony with what has preceded, with what has already justified itself as fit. There are very few monsters to be seen in wild Nature, for they express a contradiction in terms and cannot live in natural conditions. Nay more, very few monsters ever appear in wild Nature, for the germ-cell must be a viable unity, and even in its experiments it is controlled by the past to hold fast to that which is good. It is a very interesting fact that some monsters have been experimentally produced by disharmonious mongrel fertilisation of egg-cells.
(3) It is admitted that one of the characteristics of Nature's workshop is the number of automatic arrangements. In making a machine an artificer literally selects; in establishing a breed of animals Man literally selects; but Natural Selection is a metaphorical term,the sifting is very largely automatic. The survivors survive automatically in virtue of the possession of certain advantageous qualities; the eliminated disappear automatically because of the absence of certain advantageous qualities or the presence of others that are fatal. But this is not the whole truth.
The selection that occurs is not haphazard; it bears some relation to the previously established external systematisation which we call the web of life, just as social criticism which makes it difficult for the unreliable to get on is not haphazard, but bears some relation to previously established traditions and standards. The elimination in either case is remote from fortuity or capriciousness. It always has, of course, an immediate reference to the present and not to the future; but the present has been determined by a past selection of the fit and embodies that selection in an objective sieve of great subtlety. Since the sieve is a systematisation of fitness, it tends to sift towards fitness in the future as well as in the presentunless, indeed, the conditions of the future should greatly change.
Let us repeat this argument. There is in each case a line of evolution that pays; it has been reached by past variations; new variations that are congruent with the past are on the whole most likely to appear and to catch on; there fore a variation may have a prospective value. Moreover, the external systematisation which forms the sieve is the embodiment of the results of ages of sifting. Therefore fortuitousness dwindles away. Sir Ray Lankester is inaccurate in speaking of evolution as a chapter of accidents.
(4) Again, we must bear in mind that in addition to varying, organisms often take an active part in their own evolution. They are anything but passive in a game Fate plays. They may select the environment that suits them, and play the cards with which variability supplies them. And this is not automatic. If a change in instinctive behaviour (e.g., that exhibited in fashioning a wasp's nest) be the outcrop of a germinal mutation, it is not likely to persist unless it is congruent with the previously established routine, and it is not likely to come to stay unless it pass muster in the individual apprenticeship when novelties are tested, an apprenticeship in which, according to some careful students of behaviour, the slender rill of intelligence is sometimes to be detected even in those creatures most thoroughly dominated by instinctive equipment.
We see, then, that it is not legitimate to say that a mechanistic description has been given of the establishment of adaptations, or even to say, without qualification, that they have been turned out automatically in the workshop of Nature. Darwin's comparison of the process to the work of the wind expressed an error of judgment, for the blowing of the wind is altogether mechanically necessitated, and we cannot admit that this is true of organic evolution where individuality exists and counts.
But let us suppose that we have made some mistake in our argument, and that evolution is more, not less, automatic than Darwin believed. What then? We look with great satisfaction at a contrivance like a linotype printing machine, or a monorail engine with its equilibrating gyroscope, or at a watch (had not Bridgewaterism made us tired of it); they all show much skill on the part of the artificerthe original artificer at least. If we were told, however, that the contrivance we admire was not made by an artificer at all, but was turned out by an automatic machine, our admiration would simply be shifted to the designer or artificer of the original automatic machine, and we should admire all the more if the original device was very simple. So in Biology, the basal fact remains that organisms have had, and still have, the capacity of evolving adaptively. They have it in virtue of certain intrinsic qualities, previously discussed, which are much more striking than readymade fitnesses. It is because living creatures are irritable, persistent, registrative, variable, and so on, that they have been able to evolve in a consummately adaptive way. This was, of course, what Charles Kingsley had in mind in his immortal child's-story when he put into the mouth of Mother Carey the words: I make things make themselves. This is a very different view, it must be remarked, from that of an infinite regress of automatic machines, with no original designer at all; for this does not seem to us to be a clearly conceivable idea.
Time was when the multitudinous fitnesses of Animate Nature were the subject of admiring wonder, but this has shrivelled. Surely, however, the loss of wonder is not altogether creditable. If an adaptation is wrought out gradually by a co-operation of factors, that is just as wonderful as a special creation at the hands of a divine artificer; and it is more intelligible. And even if the process of evolving adaptations should turn out to be more automatic than it seems to us to have been, it remains very wonderful that living creatures should be so adaptable, should have so rich a capacity of supplying the raw materials for adaptations.
§ 3. Is There Purpose in the Inorganic Domain?
Leaving in the meantime the fact of almost universal adaptiveness in the realm of organisms, let us turn to the difficult problem of purpose. In the inorganic domain we see the river carving its course in the rock, the wind blowing the snow into beautiful wreaths, the various weathering processes making scenery, but these results are not adaptive to a future, and keeping to things as they are, we feel no reason to speak of purpose. The concept of purpose is irrelevant in the domain of the inorganic where there are no individualities and no alternatives, but rigorous concatenation and mechanical necessitation everywhere.
The hylozoist beholding the stream, flowing like an endless snake, may point to its enduring purpose. It sweeps some obstacles away and patiently undermines others; it bides its time with patience and overflows what it cannot circumvent; it consents to sinuous meanderings, and then, on a day of flood, cuts off a huge salient; it will even submit to an apparent death, becoming an underground current, if it may thereby accomplish its end of reaching the sea. But this remains fanciful and unconvincing: the stream is not a very long snake nor an individuality in any sense, it has no alternative in anything it does; it is not in the true sense an agent.
Two saving clauses are necessary. It is obvious that the inorganic domain is not chaotic, nor incoherent, nor ineffective. But it is without endeavour. It is orderly and stable, made to last, able to assume forms of great beauty, with an interesting tendency to complexify under certain conditions, but it does not reveal any resident operative purpose. It will be understood that by purpose in this discussion we mean intention, conative endeavour, anticipation of an end. We are not taking account of the employment of the word to denote use or efficiency, as when people say that the purpose of the elephant's trunk is to be a hand, or that a man worked to good purpose.
The other saving clause is, that we are not at present raising the question of the part that the inorganic has played in the world-wide genetic process in making organisms possible, and still plays in affording a basis for, and an opposition to the activities of organisms and personalities. The way in which a cradle and a home for organisms was made when as yet there was none of them is very remarkable (see Henderson, The Order of Nature, 1917), and will engage our attention later on. This may point to there having been a purpose in the institution of Nature, but not to there being a resident operative purpose in inorganic transformations.
§ 4. Purposefulness and Purposiveness in Human Behaviour.
The other pole is to be found in human affairs, where purposefulness dominates. When we give time and energy to some scheme or cause, we know that what we do is actuated by a clearly conceived purpose. No one can make sense of our life who does not recognise this, even if he call it the method in our madness. An anticipation, an ideal, with an associated tension of endeavour and glow of feeling, does as a matter of fact rule our will on many occasions. If this conceived purpose is not real, with hands and feet, we may abandon the possibility of either philosophy or science. Our life is at its highest efficiency when it is most dominated by purpose, when there is least of the unlit lamp and the ungirt loin.
At a slightly lower level, however, we recognise analogous facts. We prepare for months to build a rockery in our garden, collecting stones and tree-roots and such like in a way that perplexes our next-door neighbour, who is not in the secret, who shakes his head at the absence of purpose in our behaviour. But all that we do is actuated by a purpose, so simple that we may call it perceptual, to form in the outer world an actual counterpart of a pleasing picture which had formed itself, as we say, in our mind. If this perceived purpose is not real, nothing is real. A mental anticipation with its associated desire determines our behaviour.
We feel no difficulty in the fact that the curious can give, if he will, a tolerably complete physiological account of our various activities in making the rockerythe collecting, the carrying, the digging, and the building. For we know that however complete such an account may be either at the chemico-physical level, or at the physiological level, it never comes near being a complete scientific account until it recognises the end which serves as a point of connection for a plurality of causes, something which cannot be measured or weighedthe vision of the rockery as desirable. Not only may a teleological interpretation be put upon our behaviour; it must be put upon it, if we are to give a scientific description.
There are many difficulties in our way when we begin to draw conclusions as to the purposes of others, but there is certainty in regard to our own. We have direct experience of a clear outlook towards the future, of making plans, of desiring ends, of deliberately willing to realise an idea, of bending a multitude of means, often with some difficulty, towards a definite result, and so on. We cannot think of it without the concept of purpose. It is not merely that We put this finalistic interpretation on our conduct; we know that our purpose actuates our conduct. Among the conditions of our conduct we recognise ideal anticipations as dominant. As Lloyd Morgan puts it, there are psychological factors which we name prospective significance and interest. Pre-perceptive relationships have been established and highly developed. And such conscious relationships count, really count, every whit as much as any other natural relationship. They are not merely epiphenomenal phosphorescence; they are real conditions of the course of the process, both mental and bodily.
We must admit, then, the reality of purposeful self-determination. It is not that a psychical entity, called a purpose, functions; it is rather that our whole organism bends its bow in a particular direction and that we know this on the experiencing side as our conscious purpose and strengthen it in knowing it. We see, then, that in the human realm of ends the concept of purpose is essential; that in the inorganic domain, considered in itself, it is irrelevant; the question is as to the intermediate realm, and here the difficulties of interpretation are great.
This question of purpose is more or less clear when we are dealing with ourselves, but it becomes much more difficult when we pass to our neighbours. One of our neighbours behaves as we were doing and we credit him with the purpose of making a rockery. But it may be that he has some other purpose in view, or it may be that he is simply imitating us with a confidence that the result will be worth having. If there is this possibility of misinterpreting purpose within our own species, how careful must we be when we pass to animal behaviour.
We see a crofter making, year after year, a long line of the stones he has gathered from his field. We infer that he is arranging them so as to be least inconvenient. But one day he digs a trench beside the line and begins to lay the biggest blocks solidly within it. We know that he is going to build a wall. Now it is quite possible that this purpose was not in his mind when he began, and did not arise until the line of stones reached certain dimensions or until his clearance gave him a little leisure to think of a further improvement. This idea of an increasing purpose seems to be of great importance in Natural History, where a secondary end often appears to grow out of a primary one.
We inferred that the crofter was building a wall because we could not make sense of his activity on any other assumption; we argued by analogy from our own experience; and if we knew his language we could verify our interpretation by asking him what he was working towards. He would tell us that he had been working intermittently for years because he had the purpose of building a wall. The thought of the future wall was something actual which moved the crofter to will and to do. The thought and the will were in a real sense the ground of necessity of the wall, not less real than the stones.
But the convincingness of our interpretation of the crofter's actions as the outcome of his purpose rests, we must admit, on our recognition of him as a fellow-countryman, on his own assurance, and on parallels between his behaviour and endeavours within our own experience. How careful we must be in regard to the purposefulness of animals who are very distantly related, whose languageif they have anywe do not know, whose behaviour is cast on different lines from ours.
When we see a blacksmith take a twisted shoe from a horse's foot, heat it in the fire, hammer it, cool it, file it, and so on, we know from the very first what his purpose is, and we understand more or less every step in relation to the obvious end. But if we watch a potter or a glass blower or the like for the first time we find it more difficult from what we see to prove that he is not amusing himself; he does things that we do not see the meaning of; he ends just at the last moment by turning out something which we did not expect. There is here the warning that a sequence may be actuated by purpose through and through although we do not recognise the dominationnot even when we know the end.
§ 5. Purposiveness and Purposefulness in Animal Behaviour.
Let us pass to animal behaviour. When a dog hides an unfinished bone in a very unusual place; when Lord Avebury's dog Van goes to its box and brings out and arranges the letters T-E-A; when rooks take fresh-water mussels to a great height and let them fall on the shingle beneath so that they are broken; when a mother weasel, accompanied by one of her offspring, about to be overtaken on the links, seizes the youngster in her mouth, dashes on ahead, and lays it in a sandy hole; when beavers cut a canal right through a large island in a river; when mares, some past foaling, unite to lift up between them a number of foals on the occasion of a great flood, and so on, we say, with probable accuracy, that the creature was actuated by a definite purpose, by some sort of intention, by some anticipation of an end. The validity of this undemonstrable conclusion depends (1) on the need of assuming some degree of purpose as the connecting thread which binds together the series of acts, and (2) on what we know in other ways of the creature's psychological analogy with ourselves. If the acts composing the chain are discontinuous, the need for postulating a bond of purpose is particularly evident. If the creature has a fine brain at a high structural level, as we know to be the case with dogs, horses, elephants, and the like, the legitimacy of inferring an actuating purpose is the more probable. It may well be that the purpose is not of the same nature as our purpose when we begin a day with the intention of economising our energies at every turn for a difficult task to-morrow, or of converting as many people as possible to an acceptance of methodological vitalism. It may be that the animal's purpose is only a concrete picture with an associated desire,a cognitive disposition at a perceptual level and an associated conative disposition. So it is sometimes in mankind, especially in childhood. But it will still be legitimate to describe the behaviour as purposeful, though the purpose was not a conceived purpose. For we mean by purpose an intention of the organism, involving a perceptual or conceptual anticipation of a desired end.
Difficulties in making sure that an actuating purpose is at work begin whenever we pass from ourselves to our neighbours; they increase when we pass to big-brained higher animals; they go on increasing when we pass to cases like that of a bird building a nest. The bird goes through a certain routine of collecting and interweaving materials, of lining the interior with feathersthere may be over two thousand of them,of covering the outside with lichens which make the nest almost invisible on the bough. There is no doubt as to the adaptiveness of the chain of acts; it seems clear that the work is without justification until it is finished; we cannot make sense of the prolonged activity unless we see the whole in the light of the final result which is of great value to the individual bird, to the nestlings, and to the species in question. But we are no longer so certain that the bird's behaviour is actuated by perceived purpose. We may know, for instance, that the bird never made a nest or laid an egg before; we know that there is a remarkable rigidity in the routine which sometimes detracts from its effectiveness; and that there are occasional aberrations which suggest that the bird is not quite on the spot. In other words, we are watching an instinctive routine with a spice of intelligence. How far are we warranted in saying that it is actuated by purpose? Can there be purpose which is not clearly perceived? We propose to rank all such cases under the rubric purposiveness. It implies in the bird's case a determined endeavour, obedience to an inborn inspiration modified by intelligence, but we are not sure how far the end is in view.
Returning to the observations of Prof. J. B. Watson and Dr. K. S. Lashley on homing terns, we have to interpret such facts as these. A number of brooding terns are conveyed in hooded cages on board ship for over four hundred miles from the nesting island; they are liberated in the middle of the sea beyond all hint of land; they set off at once for home against a head wind; some of them reach home safely. How they succeeded we do not know; whether they are influenced by magnetic currents and the like we do not know; but this we do know, that they are going back to their nests. The nesting impulse remains strong for two or three weeks, and this gives an illuminating significance to the homing of these sea-swallows. They are returning to activities in which their life reaches its climax, to the continuance of which they are urged by a deep organic impulse, by an irresistible will which is not readily baulked.
But difficulties increase when we pass to the field of purely or predominantly instinctive behaviour among animals of the little brain type, such as ants and bees. We see numerous acts dovetailed in a series, correlated in a definite sequence which leads to a useful result. We cannot make the behaviour intelligible without saying: Somehow or other these several acts have been concatenated in relation to an end. But in what sense can we say that a bee on its first honey-collecting expedition is actuated by a purpose? We dare not suppose a conceived purpose and we cannot clearly think in this case of a perceived purpose, for the bee is operating effectively in a world previously unknown to it. What kind of purpose can there be? We shall speak of instinctive purposiveness, differing from perceptual purposefulness in the probable absence of any clear vision of the end.
Here we have to include the extraordinary cases where the individual works resolutely towards a goal which it never experiences. Many Digger-wasps, for instance, make elaborate preparations for offspring which they never survive to see. Since social wasps are geologically ancient it is reasonable to suppose that their behaviour originated in the distant past when the ancestors of our present-day species did survive to see their progeny. Originally, on this supposition, whether the primitive behaviour arose as an intelligent new departure (as some would say) which was hereditarily added on to the instinctive patrimony of the race, or arose as a germinal mutation (as we would say) which was intelligently tested and approved of in the individual lifetime, it is not far-fetched to suppose that it was justified to the individual in some measure of satisfaction. The mothers saw their children, which is more than they do now.
The difficulty is to understand the present-day implicit obedience to the voice of the distant past, to see how an elaborate piece of instinctive routine which does not justify itself to its possessor can retain its imperious inertia through the ages. Probably some sop unknown to us is given to the individual's interests and satisfactions. It may be, for instance, that parental instincts have become in some cases linked on to conjugal instincts, reverberations of which continue to give meaning and interest to parental care whose reward is nowadays never experienced. But the problem of making for an unseen goal is a very difficult one.
Since this was written our suggestion of an individual sop has been strikingly confirmed by the observations of Roubaud and of Wheeler. For certain tropical wasps Roubaud has shown that the queens and workers receive from the grubs, which they assiduously tend and feed, small quantities of a secreted elixir of which they are extraordinarily fond. For certain kinds of ants Wheeler has shown that there is a similar give and take (trophallaxis) between the workers and the grubs. The workers feed the grubs with chewed flesh, but they receive from their charges a douceur of secretion which seems to keep them in good heart.
But we cannot draw a line at instinctive creatures like ants and bees, where the complexity of the brain gives us some warrant for postulating ideational processes. There is hardly less effective purposelike behaviour in animals with no nerve-ganglia at all. Our typical case, already described, is the struggle between the brainless starfish and the brainless sea-urchin. Here we have a long series of difficult operations, not in the line of least resistance, not habitual, not a sequence of tropisms or reflexes, but a correlated behaviour-chain. Can we avoid saying that the starfish shows endeavour? We do not dream of calling it purposeful, but is it in any way purposive? We have to remember that the starfish has no nerve-ganglia. It has diffusely scattered neurons, a line of them up each arm, and a pentagon uniting these lines around the mouth. But there is no concentration into ganglia, and therefore we must be very parsimonious in our use of mental terms. We propose to speak of this sort of purposelike behaviour as illustrating organic purposiveness, organised endeavour.
Summing up to this point, we find that a modicum of purpose or intention is to be recognised over a very wide range, that it is a vera causa that counts, that we are not at liberty to take it or leave it, that it must enter into the scientific description. It probably represents in all cases an organismal summarising of past experiences in such a way that a definite endeavour is engendered, and behaviour is effectively dominated. But it tends to clearness to distinguish conceptual purposefulness in man's conduct, perceptual purposefulness in the intelligent behaviour of man and some animals, instinctive purposiveness in the routine behaviour of ants and bees, and organic purposiveness in the controlled and experimental endeavours of brainless animals,even in the architectural achievements of the arenaceous Foraminifera.
We began with deliberate purposefulness and worked downwards; but deliberate purposefulness is a lofty specialisation of organic purposiveness. Without implying too hard and fast boundary lines, we suggest that the word purposeful be kept for actions in which there is conscious anticipation of the constraining end. The common note in purposeful or purposive behaviour is that of the individuality or total reaction of the organism. When the organism as a whole works towards a future result which is not immediate, there is purpose in some form or other. Where the concept of purpose or intention is applied beyond the category of individuality there is bound to be confusion of thought, and care must be taken not to use it to denote the end which a particular collocation subserves or the utility which any particular collocation may have in the economy of Nature.
§ 6. The Purposelikeness of the Ordinary Functioning of the Body is Covered by the Concept of Adaptation.
The organism's behaviour as a whole is fundamentally purposelike. It makes for self-preservation and race-preservation in the widest sense. It may, on occasions, exhibit self-determination, selection, and control with reference to a distant result. In higher animals, purpose probably operates, as in man, as a cognitive anticipation of the future; in lower animals the nervous system is so different that we dare not argue from analogy as to the degree of awareness with which the conative bow is bent.
It appears probable that activities originally dominated by clearly perceived purpose, may, by individual habituation or by germinal variation, sink to a lower level of organised purposiveness. Not only the bending of the conative bow, but the hitting of the mark, becomes part of the organisation, it may be part of the inheritance, part of the organism's ready-made self. The organism as a whole hardly requires to keep its hand on the reins, purpose has become implicit. There are disadvantages in this, for the fixity sometimes leads to quaint mistakes, but it spells economy and allows more freedom for direct or individual purposive or purposeful endeavours and experiments. Just as we need the uniformity of the inorganic domain as a reliable fulcrum for our efforts, so the uniformity of organised or implicit purposiveness, besides saving organismal energy, may serve as a trustworthy stepping-stone to higher things.
When we observe an intricate machine with many regulative adjustments, such as safety-valves, we are impressed with its efficiency and purposelikeness. But we credit its maker with purpose, not itself; the concept does not grip. It is a confusion of thought to speak of a torpedo or a solar system being actuated by purpose. Only an organism or a higher form of Being can have a purpose.
Similarly in regard to the smooth working of the organs of a complex animal and even the orderly development of the same we are inclined to say that the appropriate term is adaptive not purposive. The concept of adaptation suffices for the fact that in ordinary functioning the whole and the parts are, as it were, reciprocally ends to each other. The harmonious functioning and development are the outcome of an organisation gradually wrought out through ages and are exhibited whenever suitable liberating stimuli are present. We need not here introduce the concept of actuating purpose in any form.
But it seems legitimate to lay emphasis on the view which we have tried to substantiate that the adaptive organisation did not come about mechanically, that it has behind it a long history in which germinal variability and organic purposiveness have played an important part, and that even when it may be said that variability shuffles the cards blindly, it is incumbent on the individual to play the game intelligently if it means to win.
Moreover, in the regulatory self-adjustment of the organism when functioning or development has been badly disturbed, in the activity, within the body, of independent mobile elements like phagocytes, in the regeneration of a lost lens from a tissue which does not normally give rise to one, we get just a glimpse of a residual organic purposiveness, though that has been as a whole resigned in favour of very perfect and thoroughgoing organisation.
What is meant by saying that the organism is essentially purposive, or that it has an essentially teleological or finalist aspect? This is meant, that the whole life expresses a tendency to persist, that the whole life is adapted towards self-preservation and self-expression. And if it be said that this adaptedness is the outcome of ages of mechanical variation and selection, the answer is that neither variation, nor selection can be adequately described as mechanical.
§ 7. Provisional Conclusion and Anticipation.
We have been necessarily much concerned with the outworks, and there remain many imperfectly answered questions. What, in the world-becoming as a whole, is the significance in the largest sense of the inorganic domain in its intricacy and splendour, of the myriads of invisible Protists, of the hundreds of thousands of plants, of the struggle for existence, of the prodigious mortality, of the age-long genetic process with all its groaning and travailing? To such questions we shall return in our study of Organic Evolution, conscious that behind them there loom othersIf Nature be Nature for a purpose, what is that purpose? If there be design what does it promise?
The general outcome of the present discussion is an appreciation not only of the pervasiveness of mentality in the realm of organisms, but of all-penetrating purpose as well. Looking back imaginatively on the course of evolution, we have seen the emergence of an aspect of reality which we call Life, and another aspect of reality which we call Mind, now we are getting glimpses of the emergence of another aspect of reality which we call Purpose. Of this we shall get a larger view when we come to consider the evolutionary process as a whole.
In the meantime, however, we have gained something. For while there may be difference of opinion as to terms and concepts, it has become increasingly clear that animals, and plants too, are creatures with purposeful or purposive lives, and are not to be banished from the Realm of Ends. This enriches our conception of life. It is a contribution towards a Philosophy of Nature. It makes our view of Nature and our view of Human Life more conformable.
In any case we trust that our study so far may have contributed to a deeper appreciation of the Realm of Organisms, in which we are, to say the least, no aliens. We have sought to envisage the variety of lifehundreds of thousands of distinct individualities or species; the abundance of life,like a river always tending to overflow its banks; the diffusion of life,exploring and exploiting every corner of land and sea; the insurgence of life,self-assertive, persistent, defiant, continually achieving the apparently impossible; the cyclical development of life,ever passing from birth, through love, to death; the intricacy of life,every cell a microcosm; the subtlety of life,every drop of blood an index of idiosyncrasies; the inter-relatedness of life,with myriad threads woven in a patterned web; the drama of life,plot within plot, age after age, with every conceivable illustration of the twin motives of hunger and love; the flux of life,even under our short-lived eyes; the progress of life,slowly creeping upwards through unthinkable time, expressing itself in ever nobler forms; the beauty of life,every finished organism an artistic harmony; the morality of life,spending itself to the death for other than individual ends; the mentality of life,sometimes quietly dreaming, sometimes sleep-walking, sometimes widely-awake; and the victory of life,subduing material things to its will, and in its highest reaches controlling itself towards an increasing purpose.
It is something to have found warrant for regarding the Realm of Organisms as pervaded with active purposiveness. At a later stage in the argument we shall show that there is at least a presumption in favour of the view that Nature is Nature for a purposean increasing and transcendent purpose. At this stage it seems as if part of that purpose were the emergence of individuality, mind, freedom, purpose. This thrilling word purpose, expressing the most real fact in our personal experience, brings us at this half-way house to our provisional conclusion which is, we confess, too large for the premises, that individualities with mind, with freedom, and with purpose, cannot be accounted for in terms of a ground of reality without mind, without freedom, without purpose. Therefore let us humbly seek after, if haply we may find, more than the footprints of the Creator, who beholding all the works of His hands found them good for His purpose.
Our consideration of the realm of organisms has shown us the apartness of living creatures and how they transcend mechanical and dynamical formulation, the important rôle played by behaviour with a definitely mental aspect, the pervasiveness of beauty, and the large proportion of time and energy devoted to activities which make not for self-preservation but for race-welfare. We find, in fact, in Animate Nature far-reaching correspondences to our ideals of the True, the Beautiful, and the Good,which suggest a rehabilitation of Natural Theology.
Taking a wide sweep we gain another great impressionthat of almost universal adaptiveness. Every living creature is a bundle of adaptations. It matters comparatively little that we are to some extent able to describe the process by which these adaptations have arisen (the imperfections of this description to be considered later), for the basal fact remains that living creatures have had the capacity of evolving thus adaptively. The adaptiveness depends on intrinsic qualities, previously discussed, which are more striking than readymade fitnesses.
Adaptations may be classified as:(1) structural arrangements with internal or external reference, (2) co-ordinating functional adjustments of a special sort, including regulatory integrations, and (3) inter-organismal adaptations. The result of the last is a systematisation or co-ordination of lives, world-wide in its scope, and often extraordinarily subtle in its accomplishment.
In the inorganic domain we find rigorous concatenation, a dominance of mechanical necessitation. There are no unique individualities, no alternatives; and the concept of purpose is irrelevant (except when we are thinking of the significance of the evolutionary trend as a whole). On the other hand, in the human realm of ends, ideal anticipations are dominant. Our conduct, implies purposeful self-determination. There is no difficulty until we begin to consider the realm of organisms,between the inorganic and the human.
It may be said that the organism as a whole is characteristically purposive,a unity in which the whole and the parts are reciprocally ends to each other. It shows some measure of self-determination; its behaviour is regulatory, selective, controlled; the activities of its parts are correlated in reference to the preservation and continuance of the individual and the race. The development is also purposive through and through. And if it be said that in all this the organism is merely obeying its hereditary constitution adapted to react to an appropriate environment, it must be observed that this hereditary constitution is determined by the selection of variations, many of which seem like experiments in self-expression, and that all the innate variations are, so to speak, cards which have to be played by organismal endeavour. This endeavour is ipso facto purposive and is along the lines of previous play in some measure selected by the organism.
Passing above what may be called organised purposiveness, we may recognise instinctive purposiveness, often with its paradoxical quality of making towards a goal which the individual never experiences. At a higher level, among intelligent animals, it becomes possible to speak of a perceived purposean imaging of the end which has compelling force. Thus we are led to an appreciation not only of the pervasiveness of mentality in the realm of organisms, but of the all-penetrating purposiveness as well.