On the whole then, judging from man himself (and it seems most cautious and scientific to derive our main evidence from the being that we are best acquainted with), it certainly seems to me that, though the external conditions are a very important factor in Variation, the central explanation of this phenomenon should be sought in an inner law of Growth—a law of expansion more or less common to all animate nature. Partly because, as said before, the unfolding of the creature from its own needs and inward nature is an organic process, and likely to be persistent, while its modification by external causes must be more or less fortuitous and accidental and sometimes in one direction and sometimes in another; partly also because the movement from within outwards seems to be most like the law of creation in general. Under this view the external conditions would be considered a secondary—though important cause of modification; and regarded rather as the influences that give form and detail to the great primal impulse of growth from within; while the creature's own ingenuity and good luck would occupy the ground between the two—as the means whereby the external conditions in each individual case would be turned to account to satisfy the inner needs, or the inner life would be accommodated to the external conditions.
If we take the external view of Variation—which is the one most favoured by modern science—modification or race-growth appears as an unconscious or accretive process, similar to the formation of a coral reef. There is no line of growth native in the race itself, but at any moment it is supposed to have an equal tendency to vary in any direction. Surrounding conditions act selectively; and by a process of weeding out certain types survive; small successive modifications are thus accumulated; and gradually and in the lapse of ages a more pliable and differentiated creature, and more adaptable to a variety of conditions, is produced—in whom however mind is incidental, and has played but small part in the creature's evolution. This in the main is the Darwinian-evolution theory.
If we take the internal view, growth is from the first eminently conscious. Every change begins in the mental region—is felt first as a desire gradually taking form into thought, passes down into the bodily region, expresses itself in action (more or less dependent on conditions), and finally solidifies itself in organisation and structure. The process is not accretive, but exfoliatory—a continual movement from within outwards. When the desire or mental condition, which at first was painfully conscious, has overcome opposition and established itself in altered bodily structure, it has done its work, and becomes unconscious—the bodily function continuing for a long period to act automatically, till finally it is thrown off to make room for some later development. Thus race-growth or Variation is a process by which change begins in the mental region, passes into the bodily region where it becomes organised, and finally is thrown off like a husk. This may be called the theory of Exfoliation.
To illustrate our meaning. Let us take the development of an eye. In the amoeba there is a dim pervasive sensitiveness to light over the whole body, but there is no eye, nothing that we should call vision. Still this vague sensitiveness is of use to the amoeba. The shadow of its prey falling upon the creature and exciting a sensation hardly yet differentiated from touch helps to guide its movements. On this dim sensation it relies to some extent; its attention is directed towards it. Gradually, and in some descendant form, there comes to be a point on the body on which this attention is most specially concentrated. The faculty is localised; and from that moment a change is effected there, a differentiation and a special structure; everything that favours sensitiveness is encouraged at that place, everything that dulls it is removed; and before long—there is a rudimentary eye. To-day we use our perfected eyes, and are hardly conscious that we are doing so; but every power of vision that we have was thus won for us by some lowlier creature, step by step, with effort and with concentration. Or to take an illustration from society. To-day society is ill at ease; a dim feeling of discontent pervades all ranks and classes. A new sense of justice, of fraternity, has descended among us, which is not satisfied with mere chatter of demand and supply. For a long time this new sentiment or desire remains vague and unformed, but at last it resolves itself into shape; it takes intellectual form, books are written, plans formed; then after a time definite new organisations, for the distinct purpose of expressing these ideas, begin to exist in the body of the old society; and before so very long the whole outer structure of society will have been reorganised by them. After a few centuries the ideas for whose realisation we now fight and struggle with an intense consciousness will have become commonplace, accepted institutions, more or less effete and ready to succumb before fresh mental births taking place from within.
The modern evolution theory would maintain that among many amoebas and descendant forms, one would at last by chance be born having the usual sensitiveness localised in a particular spot, and, surviving by force of this advantage, would transmit this "eye" to its posterity; or that in the progress of society, new economic conditions having arisen, that people would prosper best which most effectually and rapidly adapted itself to them. But though there is doubtless truth in this view, yet it seems, when all has been said, to be inadequate and even feeble; it omits at least one half of the problem. If we look at ourselves, as already pointed out, we see the two forces—the inner and the outer—acting and re-acting on each other. May it not be so in animals? Lamarck, poorly off, blind, derided, was a true poet. "Animals vary from low and primitive types chiefly by dint of wishing"—and the world laughed and still laughs. But it was his deep sympathy even with the worms and insects (which he studied till he could discern them with his mortal eyes no longer) that led Lamarck to see the human nature and the human laws that moved within them; and as his outward sight grew dim there arose before him the inward vision of the true relationship which binds together all living creatures—which was indeed a vision of divine things, and as different from the mere mechanism-theory of the survival of the fittest as the sight of the starry heavens is different from a governess's lesson on the use of the globes.
On the theory of Exfoliation, which was practically Lamarck's theory, there is a force at work throughout creation, ever urging each type onward into new and newer forms. This force appears first in consciousness in the form of desire. Within each shape of life sleep needs and wants without number, from the lowest and simplest to the most complex and ideal. As each new desire or ideal is evolved, it brings the creature into conflict with its surroundings, then gaining its satisfaction externalises itself in the structure of the creature, and leaves the way open for the birth of a new ideal. If then we would find a key to the understanding of the expansion and growth of all animate creation, such a key may exist in the nature of desire itself and the comprehension of its real meaning. It is not certain that it can be found here; but it may be.
What then is desire in Man? Here we come back again, as suggested at the outset, to Man himself. Though we see pretty clearly that desire is at work in the animals, and that it is the same in kind as exists in man, still, among the animals it is but dim and inchoate, while in man it is developed and luminous; in ourselves, too, we know it immediately, while in the animals only by inference. For both reasons, therefore, if we want to know the nature of desire—even to know its nature among animals—we should study it in Man. What then is this desire in Man, which seems to be the instigation and origin of all his growth and development? At first it seems a hydra-headed senseless thing without rhyme or reason; but the more one regards it the more clearly one sees that even in its lowest forms it is steadily building up and liberating all the functions of the human being. In its most perfect form—as in what we call Love—it is the sum and solution of human activities, that in which they converge, for which they all exist, and without which they would be considered useless. The more you look into this matter, the plainer it becomes. The lesser desires—the self-preservation desires—hunger, thirst, the desire of power—exist, but when they are satisfied they empty themselves into this one; they find their interpretation in it. The other desires are nothing by themselves—the most absorbing, avarice, ambition, desire of knowledge, taken alone, stultify themselves—but love perpetuates itself; it is a flame which uses all the rest as its fuel. And this Love, which is the culmination of desire, does it not appear to us as a worship of and desire for the human form? In our bodies a desire for the bodily human form; in our interior selves a perception and worship of an ideal human form, the revelation of a Splendour dwelling in others, which—clouded and dimmed as it inevitably may come to be—remains after all one of the most real, perhaps the most real, of the facts of existence? Desire, therefore—as it exists in man, look at it how you will—as it unfolds and its ultimate aim becomes clearer and clearer to itself, is seen to be the desire and longing for the deliverance and expression of the real human Being. May it not, must it not, be the same thing in animals and all through creation? Beginning in the most elementary and dim shapes, does it not grow through all the stages of organic life clearer and more and more powerful, till at last it attains to self-consciousness in humanity and becomes avowedly the leading factor in our development?
The desire which runs through creation is one desire. Rudimentary at first and hardly conscious of itself, throwing out a tentacle here, a foot there, developing an eye, a claw, a nostril, a wing, it seeks in innumerable shapes and with ever partial success to realise the image it has dimly conceived. The animal kingdom is the gymnasium, the school, the antechamber, of humanity; to walk through a zoological garden is to see the inchoate types of man, perched on branches, or browsing grass, or boring holes in the ground; it is to witness a grand rehearsal of some stupendous part, whose character we do not even yet fully see or understand. From such half-conscious beginnings the desire grows, its aim becomes clearer, till in the higher animals—the horse, the dog, the elephant, the bird, and many others—it becomes a marked and unmistakable force drawing them close to man, uniting them to him in a kind of acknowledged kinship, and as obviously at work modifying their structure as can be. Finally in man himself it becomes an absorbing power; love becomes a conscious worship of the divine form; generation itself is the means whereby, in time, the supreme object of desire is realised. When at last the perfect Man appears, the key to all nature is found, every creature falls into its place and finds its Interpreter, and the purpose of creation is at last made manifest.
The Theory of Exfoliation then differs from that very specialised form of Evolution which has been adopted by modern science, in this particular among others: that it fixes the attention on that which appears last in order of Time, as the most important in order of causation, rather than on that which appears first; and recalls to us the fact that often in any succession of phenomena, that which is first in order of precedence and importance is the last to be externalised. Thus in the growth of a plant we find leaf after leaf appearing, petal within petal—a continual exfoliation of husks, sepals, petals, stamens and what-not; but the object of all this movement, and that which in a sense sets it all in motion, namely the seed, is the very last thing of all to be manifested. Or when a volcano breaks out—first of all we have a cracking and upheaval of superficial layers of ground, then of layers below these, then the outflow of lava, and last of all the uprush of the inner fires and forces which set it all agoing. What appears first in time, or in the outer world is—in the case of the building of a house, the making of bricks; in the case of the flower, the outermost bracts; in the case of a volcano, the stirring of the surface of the ground; and in the case of Life on the Earth, the appearance of protoplasms and primordial cells. The bricks are not the cause of the house (if indeed the word "cause" should be used here at all) but rather the house—or the conception of the house—is the cause of the bricks; and the cells are not the origin of Man, but Man is the original of the cells. The rationale of sea-anemones and mud-fish and flying foxes and elephants has to be looked for in man: he alone underlies them. And man is not a vertebrate because his ancestors were vertebrate; but the animals are vertebrate, because or in so far as they are forerunners and offshoots of Man.
It has been frequently said that great material changes are succeeded by intellectual and finally by moral revolutions—as the conquests of Alexander passed on into the literary expansion of the Alexandrian schools and thence into the establishment of Christianity, or as the mechanical developments of our own time have been followed by immense literary and scientific activities, and are obviously passing over now into a great social regeneration; but a reconsideration of the matter might, I take it, lead us not so much to look on the later changes as caused by the earlier, as to look on the earlier as the indications and first outward and visible signs of the coming of the later. When a man feels in himself the upheaval of a new moral fact, he sees plainly enough that that fact cannot come into the actual world all at once—not without first a destruction of the existing order of society—such a destruction as makes him feel satanic; then an intellectual revolution; and lastly only, a new order embodying the new impulse. When this new impulse has thoroughly materialised itself, then after a time will come another inward birth, and similar changes will be passed through again. So it might be said that the work of each age is not to build on the past, but to rise out of the past and throw it off; only of course in such matters where all forms of thought are inadequate it is hard to say that one way of looking at the subject is truer than another. As before, we should endeavour to look at the thing from different sides.