Evolution

by F. B. Jevons

Both theories, however, base themselves upon what is, and profess that their conclusions follow logically from it. If, then, they differ in their conclusions it is because they differ in their diagnosis of what is. Both admit the existence of faith; but one regards faith as a fact in the pathology of human reason, the other regards it as the normal mode of our common reason's operation. The latter, therefore, requires to postulate causes which will account for the correctness of the common faith of mankind; the latter, causes which have resulted in the common illusion of mankind.

It seems, then, that even in evolution we do not escape after all from the indeterminate and conditional knowledge, which science offers, to the absolute certainty of accomplished fact. Every theory of the past history of the world is just as conditional, just as much dependent on an "if," as the hypothetical laws of science, for any such theory is dependent on the view it takes of what is, and is correct only if that view is correct.

The theories of evolution which we have called the Optimistic and the Pessimistic interpretations of evolution are avowedly based on the assumption that a large part of the common faith of mankind is a mental or moral disease. According to Mr. Herbert Spencer the faith that we can know what is real is an illusion: the Real is the Unknowable. According to Professor Huxley the common faith in the freedom of the will is an illusion: necessity is the law of the uniformity both of Nature and of human nature. In thus declining to accept the testimony of the moral and religious consciousness as evidence of what is, both philosophers were influenced by the belief that it is science alone which is capable of ascertaining and demonstrating what is and what actually does happen. This belief, however, we have ventured to suggest, overlooks two facts. One is that the abstract sciences do not even profess to state what actually does happen: they simply affirm that, if the conditions stated in their various laws are the only conditions operative, the only result will be that stated by the particular law in question. Thus science does not concern itself with what is or does happen, but solely with what would be or would happen under certain (usually impossible) conditions. The other point overlooked is that the historical or comparative sciences are also only hypothetically true. All that their laws undertake to demonstrate is that, if certain consequences constitute the whole of an observed effect, then the only conditions antecedently operative were those stated in the law. Here too, then, science does not even claim to prove what is or demonstrate what does happen, but assumes that we know it or find it out, in some way with which science does not concern itself. If we do know and can know what is, science can tell us what were the conditions that produced it.

The question, then, that we have to put to any theory of evolution—that is, to any theory which professes to state the process by which the totality of things has come to be what it is—is, "Does it account for that totality? do the causes which it assumes to have been at work account for all that is?" Now, a priori it was not to be expected that evolution would in its infancy, and it is still young, succeed in accounting for all things; and there were special reasons in the circumstances under which it first took its modern scientific shape which necessarily limited its earliest attempts to grasp the totality of things. It would, however, be absurd to judge the principle by the first attempt to apply it, and to condemn it because it has not done in a moment what with time it assuredly will succeed in effecting. At the same time, it can only effect that wider success by refusing to stereotype its first errors and by declining to bind itself to the dogma that what it has succeeded in explaining is all that there is to explain, or that that alone is or happens which its present assumptions or laws are capable of accounting for. There lies the danger which threatens to check the further development of the theory of evolution—in the dogmatism which pretends to set aside common sense and the common reason, and arrogates to itself the sole right of saying what is; and succeeds in doing so by the simple but circular argument that that alone is or happens which can be accounted for by the laws that regulate the movements of things in space or that follow from the struggle for animal existence.

Historically, the theory of evolution in its first manifestation was an extension to the historical sciences generally of a purely biological conception, that of the origin of species as a consequence of the struggle for existence. It was found that much else in the manifold of what is, many other differences between related things, besides the differences which mark off one species of animals from another, might be accounted for, historically, by the theory that those differences were but the sum and the accumulation of an infinite number of small modifications which had given the thing an advantage over its rivals in the struggle for existence. Strictly speaking, all that this remarkable and wide-reaching discovery implied as a matter of logic was that between animals and things not animal there existed an analogy or resemblance, in virtue of which it was logical to argue from things animal to things not animal just so far as the resemblance between them went, but not further. Very naturally, however, it happened that with this originally biological conception all its biological implications were taken over, and it was (and is) argued not merely that there are great and fruitful resemblances between, say, society and an animal organism, but that societies are animal organisms. In fine, sociology was treated as a department of biology. The fallacy that science demonstrates what is, and that what science does not account for has no real existence, thus made its appearance simultaneously with the birth of the evolution theory. The resemblances between the evolution of the social organism and of animal organisms could be accounted for by the biological theory of the struggle for existence; the differences, therefore, must be denied or laboriously explained away. With the growth of sociology, however, it is becoming apparent that the evolution of society has laws, some of which do indeed coincide with those of animal evolution, but others of which are peculiar to sociology in the same sense as the laws of chemistry are distinct from those of physics. Sociology is accordingly revolting from its bondage to biology: the plain fact that society is not an animal is beginning to make itself felt. The resemblances between the organisation of society and that of an animal are freely admitted, but the differences are beginning to claim consideration also; and the sound doctrine is beginning to assert itself that by experience alone, experience of what is, and not by any a priori dogmatism as to what in the name of science must be, can we tell how far the resemblances extend as a matter of fact and where the differences begin. That the evolution theory must be the gainer by thus admitting the facts instead of denying their existence is clear; if sociology is not a branch of biology, and yet the two sciences have certain laws in common, a great step is at once taken towards demonstrating the existence of certain general principles of evolution which are higher than the laws of either, or perhaps than of any, particular science.

The tendency of the scientific theories prevailing for the moment to deny the existence of what they cannot, for the moment, account for, is exemplified in another way by the theory of the survival of the fittest. It was shown by Darwin that, granted the tendency to variation in animals, the struggle for existence was enough in its results—as he had the genius to discern them—to account for the origin of species. The struggle for existence is a fact, and thus animal evolution was based on what is, on positive fact. To apply the same process of argument to human and social evolution was perfectly scientific and legitimate. What is neither scientific nor legitimate is to maintain, explicitly or implicitly, that the totality of human activity is engaged and exhausted in the struggle for existence. Self-preservation is undoubtedly a powerful instinct, but it is not the only instinct even of animals, and is not always the most powerful in man—or in the brute. That there are resemblances between man and his fellow-creatures, the brutes, and that so far as those resemblances extend, man and the animals have been, and are, subject to the same laws of evolutions, are facts which may be heartily admitted, but which neither authorise us to deny the existence of specifically human peculiarities, nor warrant us in trying to deduce the differences from a law which applies only to the resemblances. If the evolution theory is to state the process by which the totality of things has come to be what it is, it must begin by facing the whole of the facts—in this case by admitting that not only have the fittest to survive survived, as is natural in a struggle for existence, but that progress, æsthetic, ethical, and religious, has been made.

The denial of this fact may either be open and avowed, as, for instance, when the reality of the religious ideal is formally denounced; or it may be tacit and implied, as, for instance, when moral progress is defined as adaptation to environment, i.e. as not progress at all, or when the freedom of the will is denied, i.e. when approximation to the ethical ideal is maintained to be a thing not under our control. Tacit or avowed, this denial proceeds upon the fallacy that the laws of science, as understood and formulated at any particular moment, are the sole test and constitute our only knowledge of what is. But the interests both of the common sense of mankind and that specially organised form of common sense which we know as science require a protest against that fallacy: it is opposed to the principle on which scientific knowledge rests, and it would be fatal, if acted upon, to all further development of that knowledge.

The principle upon which science rests is that its laws are capable of verification, and that they are verified when and if they are confirmed by experience. The final appeal of science is to the evidence of consciousness, the only evidence of what is that we possess: the only evidence of the truth and accuracy with which an eclipse has been calculated is the evidence of our senses that the eclipse does take place and is visible in the place and at the time predicted. If a hypothesis predicts results which as a matter of observation do not take place, the hypothesis is judged so far inaccurate or inadequate: what is over-rides our preconceived opinions, even if they be the hypotheses of science, as to what ought to be or will be. It is the ever-open appeal to the final court of fact, of what is, that condemns false assumptions, guarantees the truth of science, and safeguards the freedom of scientific inquiry. To allow any group of men, however eminent, or any body of science, however sound, to deprive us of this right of appeal and bid us disbelieve in the evidence of our own senses, if it contradicts their theories, would be to submit to the tyranny of dogmatism, and to be faithless to the cause of truth.

Fortunately, though the unconscious and therefore ill-considered metaphysics of some men of science have tended in the direction of scientific dogmatism, the practice of science has been in the opposite direction. In practice science has owed much of her progress to the study of "residual phenomena." Phenomena which the laws of science for the moment could not account for have not been denounced as illusions, or ruled out of court as non-existent or beneath the notice of science: they have been accepted as facts, as part of the totality of things which it is the ambition of science to account for; and, accepted as such, they have led, it may be, to the discovery of a new planet or a new element, but always to the discovery of fresh truths, which never would have enriched the page of science had science refused to take cognisance of facts the laws of which it had not at the time discovered.

In demanding, then, that any theory which professes to account for the totality of things should recognise the fact of ethical and æsthetic progress, and that all progress is willed and purposed, we are seeking not to cramp science but to enlarge its bounds, not to introduce a new scientific method, but to extend the application of existing methods, and to carry out the principle on which the truth of science and the freedom of scientific inquiry are based. The laws which enable the physicist to explain the mechanical action and reaction of things do not suffice to explain the reactions studied by the chemist. The laws of chemistry are inadequate for the purposes of the biologist. It is but an extension of the same principle when the student of the anthropological sciences finds it necessary to assume, or rather discovers, that the laws of animal existence do not wholly account for everything that man does; and it is to these sciences that we must look for the next important and fruitful modification of the general theory of evolution. It is to them, dealing as they do with the highest product of evolution, that we must look for the truest interpretation of evolution. On the principle that to understand what a thing is we must not reduce it to its lowest terms, but look at it in its highest manifestation, we must judge the evolution process by its highest phase, by all that it is capable of, and not by the least we can, by scientific abstraction, leave in it. And the sciences which, merely to maintain their scientific existence, have a vital interest in insisting on the reality of will and purpose as causes which have influenced the direction of the evolution process are the sciences which deal with man.