3. CREATIVE EVOLUTION
With this new orientation, evolution appears to us as something quite different from the blind and dreary mechanism of struggle and destruction which Darwin and Spencer described. We sense duration in evolution, the accumulation of vital powers, the inventiveness of life and mind, “the continual elaboration of the absolutely new.” We are prepared to understand why the most recent and expert investigators, like Jennings and Maupas, reject the mechanical theory of protozoan behavior, and why Professor E.B. Wilson, dean of contemporary cytologists, concludes his book on the cell with the statement that “the study of the cell 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.” And everywhere, in the world of biology, one hears of the rebellion against Darwin.13
Darwinism means, presumably, the origin of new organs and functions, new organisms and species, by the natural selection of favorable variations. But this conception, hardly half a century old, is already worm-eaten with difficulties. How, on this theory, did the instincts originate? It would be convenient to conceive them as the inherited accumulation of acquired habits; but expert opinion closes that door in our faces,—though some day that door may be opened. If only congenital powers and qualities are transmissible, every instinct must have been, on its first appearance, as strong as it natively is now; it must have been born, so to speak, adult, in full panoply for action; else it could not have favored its possessor in the struggle for existence. If, on its first appearance, it was weak, it could have achieved survival value only through that acquired strength which (by current hypothesis) is not inherited. Every origin is here a miracle.
And, as with the first instincts, so with every variation: one wonders how the change could have offered, in its first form, a handle to selection. In the case of such complex organs as the eye, the difficulty is discouraging: either the eye appeared at once, full-formed and competent (which is as credible as Jonah’s introspection of the whale); or it began with a series of “fortuitous” variations which, by a still more fortuitous survival, produced the eye. At every step the theory of a mechanical production of complicated structures by a blind process of variation and selection presents us with fairy-tales that have all the incredibility of childhood’s lore, and little of its beauty.
The most decisive difficulty, however, is the appearance of similar effects, brought about by different means, in widely divergent lines of evolution. Take as example the invention of sex as a mode of reproduction, both in plants and in animals; here are lines of evolution as divergent as could be, and yet the same complex “accident” occurs in both. Or take the organs of sight in two very distinct phyla—the molluscs and the vertebrates; “how could the same small variations, incalculable in number, have ever occurred in the same order on two independent lines of evolution, if they were purely accidental?” More remarkable still,
nature arrives at identical results, in sometimes neighboring species, by entirely different embryogenic processes . . . . The retina of the vertebrate is produced by an expansion of the rudimentary brain of the embryo . . . . In the mollusc, on the contrary, the retina is derived from the ectoderm14 directly . . . . If the crystalline lens of a Triton be removed, it is regenerated by the iris. Now the original lens was built out of the ectoderm, while the iris is of mesodermal origin. What is more, in the Salamandra maculata, if the lens be removed and the iris left, the regeneration of the lens takes place at the upper part of the iris; but if this upper part of the iris itself be taken away, the regeneration takes place in the inner or retinal layer of the remaining region. Thus parts differently situated, differently constituted, meant normally for different functions, are capable of performing the same duties and even of manufacturing, when necessary, the same pieces of the machine.15
So, in amnesia and aphasia, “lost” memories and functions reappear in regenerated or substituted tissues.16 Surely we have here overwhelming evidence that there is something more in evolution than a helpless mechanism of material parts. Life is more than its machinery; it is a power than can grow, that can restore itself, than can mould to its own will some measure of environing circumstance. Not that there is any external design determining these marvels; that would be merely an inverted mechanism, a fatalism as destructive of human initiative and of creative evolution as the sombre surrender of Hindu thought to India’s heat. “We must get beyond both points of view—mechanism and finalism—as being, at bottom, only standpoints to which the human mind has been led by considering the work of men”: we thought at first that all things moved because of some quasi-human will using them as instruments in a cosmic game; and then we thought that the cosmos itself was a machine because we had been dominated, in character and philosophy, by our mechanical age. There is a design in things; but in them, not outside; an entelechy, an inward determination of all the parts by the function and purpose of the whole.17
Life is that which makes efforts, which pushes upwards and outwards and on; “always and always the procreant urge of the world.” It is the opposite of inertia, and the opposite of accident; there is a direction in the growth to which it is self-impelled. Against it is the undertow of matter, the lag and slack of things toward relaxation and rest and death; at every stage life has had to fight with the inertia of its vehicle; and if it conquers death through reproduction, it does so only by yielding every citadel in turn, and abandoning every individual body at last to inertia and decay. Even to stand is to defy matter and its “laws”: while to move about, to go forth and seek, and not, plant-like, to wait, is a victory purchased at every moment by effort and fatigue. And consciousness slips, as soon as it is permitted, into the restful automatism of instinct, habit, and sleep.
At the outset life is almost as inert as matter; it takes a stationary form, as if the vital impulse were too weak to risk the adventure of motion. And in one great avenue of development this motionless stability has been the goal of life: the bending lily and the majestic oak are altars to the god Security. But life was not content with this stay-at-home existence of the plant; always its advances have been away from security towards freedom; away from carapaces, scales and hides, and other burdensome protections, to the ease and perilous liberty of the bird. “So the heavy hoplite was supplanted by the legionary; the knight, clad in armor, had to give place to the light free-moving infantryman; and in a general way, in the evolution of life, just as in the evolution of human societies and of individual destinies, the greatest successes have been for those who accepted the heaviest risks.”18 So, too, man has ceased to evolve new organs on his body; he makes tools and weapons instead, and lays them aside when they are not needed, rather than carry all his armament at every step, like those gigantic fortresses, the mastodon and the megatherium, whose heavy security lost them the mastery of the globe. Life may be impeded, as well as aided, by its instruments.
It is with instincts as with organs; they are the tools of the mind; and like all organs that are attached and permanent, they become burdens when the environment that needed them has disappeared. Instinct comes ready-made, and gives decisive—and usually successful—responses to stereotyped and ancestral situations; but it does not adapt the organism to change, it does not enable man to meet flexibly the fluid complexities of modern life. It is the vehicle of security, while intellect is the organ of an adventurous liberty. It is life taking on the blind obedience of the machine.