On only one of these points do I propose to say a few words—that of the possible inheritance of acquired variations.
Let us restate the problem here for the sake of clearness. There is, according to the suggestion put forward in this chapter, an interneural evolution, leading to an harmonious development of the neuroses in the individual brain. But this special evolution of the brain is nowise independent of the more general evolution of the body. The human being, as an organism, is still subject to natural elimination and human selection. Elimination through the action of surrounding physical conditions, although it has played some part in the evolution of man, is not a factor of the first importance. Elimination through enemies is more important, but has not much bearing on the question at present before us—the evolution of the conceptual. Elimination by competition, again, though a factor of yet greater importance in human evolution, has, nevertheless, so far as individuals are concerned, but little bearing on our present question. Few are eliminated through the absence of the conceptual faculty. Natural elimination, then, is, as Mr. Wallace well pointed out, practically excluded in this matter. No doubt, in the struggle between tribes and nations, that community is most likely to be successful in which there is rational guidance. No doubt, during the earlier phases of the development of man on our islands, the elimination of the irrational was a factor in progress. But if we take the last three centuries of English history, I doubt whether it can be shown that there has been much elimination determined by the relative absence of conceptual ideas and emotions.
Human selection has been a much more important factor. Those individuals which showed the higher types of intellectual thought have been constantly selected. Riches, rank, and social position have been bestowed upon them. Of course, there have been exceptions; great intellects have been allowed to languish in their lifetime, and have only obtained recognition through their works after death. But every day there is less chance of a genius dying in a garret. And the best intellects, being thus selected and chosen out from among their fellow-men, form to some extent a distinct social class. Segregation is thus effected; and intermarriage takes place within this intellectual caste, with the result that the conditions are eminently favourable for the inheritance of intellectual qualities.
Now, is this process of selection of the intellectual, this segregation into a caste, and the inheritance of innate intellectual qualities sufficient to account for the facts of intellectual progress; or must we call in to our aid the inheritance of individual increments? I confess I cannot say. Direct and satisfactory evidence, one way or the other, is almost impossible to obtain.
Must we, then, leave the question undecided? I think we must so far as direct evidence is concerned. I may have a general belief that there has been some transmission of acquired increment of intellectual faculty. But unless I can substantiate it by definite facts, I cannot expect to convince any one who holds the opposite view. And definite facts of sufficient cogency I am unable to adduce. It is practically impossible to exclude the influence of human selection; and unless we can do this the followers of Dr. Weismann will not be satisfied.
Still, general belief—which means the net result of one's consideration of the subject—counts for something. We must remember the question is one of origin, and not of guidance. The guidance of human selection is unquestioned and unquestionable. But when we consider the intellectual progress of the last three centuries, and ask whether all this has originated in fortuitous brain-variations, which human selection has simply picked out from the total mass of available material, an affirmative answer seems to me a little difficult of acceptance. There seems to have been a definite tendency to vary in this particular direction, a general raising of the intellectual level, which is difficult to account for unless it be due to the persistent employment of the intellectual faculties.
To put the matter in another way. I do not think that, during the last three centuries, there has been a large amount of elimination of the unintellectual. Such elimination as there has been of this nature has probably been more than compensated by the slower rate of multiplication of the intellectual classes. Elimination, then, in this matter may be practically disregarded. But it is obvious that selection, without the removal or exclusion of the non-selected, does nothing to alter the general level[KN] with regard to the particular quality or faculty concerned. It is merely a classification of the individuals in order of merit in this particular respect. It is, in a word, a segregation-factor. It arranges the individuals in classes, but it does not alter the position of the mean around which they vary.
Let me explain by means of an analogous case. Fifty boys, who have been admitted to a public school, await examination in a class-room. They are at present unclassified, but there is a mean of ability among the whole fifty. A week afterwards they are distributed in different forms. Some are selected for a higher form, others have to take a lower place. But though selection has classified the material, it has not altered the position of the mean of ability among the fifty boys. This can only be done by expelling a certain number or excluding them from the school.
Granted, therefore, that elimination is practically excluded, human selection can at most classify the individuals according to their intellectual faculties. It cannot raise the mean standard of intellectuality. If, therefore, this mean standard has been raised during the last three centuries, there has been a tendency to vary in this particular direction, which may,[KO] to say the least of it, be due to the inheritance of individual increment.
I am, of course, aware that the matter is complicated by the increased and increasing diffusion of knowledge through the printing-press and by the extension and improvement of education. But education, to take that first, though it may raise the level of each generation, can have no cumulative effect. For the effects of education cannot, on Professor Weismann's hypothesis, be inherited. You may educate brain and muscle in the individual, but his heir will inherit no good or ill effects therefrom. Each generation goes back and starts from the old level. There is no summation of effect; or, if there is, it tells so far against Professor Weismann.
And with regard to the diffusion of knowledge, this, though it brings more grist to the intellectual mill, can have no effect in raising the mean standard of excellence in the mill itself. There is more to grind; but this does not improve the grinding apparatus; or, if it does, it tells so far against Professor Weismann's hypothesis. To vary the analogy, the diffusion of knowledge increases the store of available food; but it does not bring with it any additional power of digesting the food; or, if it does, it may be through inherited increments of mean digestive power.
It may, however, be maintained that there is no conclusive proof that the mean intellectual level of Englishmen to-day is any higher than it was in the days of the Tudors. If so, of course, my argument falls to the ground. I have no desire to dogmatize on the subject. I merely set down the reasons, such as they are, and for what they are worth, which lead me to entertain a general belief that the intellectual progress of Englishmen during the past three hundred years has been in part due to the inheritance of individually acquired faculty.
Mental evolution, then, is the metakinetic equivalent of interneural, or, in us vertebrates, brain-evolution. The brain forms a kinetic system in some sense independent of, and yet in constant touch with, the kinetic system of the world around. Its kineses, though they do not resemble, yet more or less accurately represent or symbolize, the kineses of the surrounding universe. As the kineses of the world around are interdependent and harmonious, so are the neural kineses of the brain interdependent and harmonious. And no modification of this kinesis which is out of harmony with the kinetic system already established in the brain can be incorporated with that existing system. Such attempted modification is eliminated through incongruity.
Associated with this brain-kinesis, and forming its inner aspect, is a metakinetic system in which the higher manifestations rise to the level of full consciousness; others form sub-conscious states; others are unconscious. But the whole form a coherent system answering to the coherent kinetic system.
Consciousness is thus associated only with the phenomena of that kinetic microcosm which we call the brain (or other interneural system). Obviously, therefore, it does not and cannot deal directly with anything outside the brain. Its knowledge is solely and entirely a knowledge of the representative occurrences of the interneural system. But out of these occurrences a surrounding world of phenomena is constructed in mental symbolism.
The brain itself, however, is part of the world of phenomena thus constructed in mental symbolism; and the world, therefore, dissolves in pure idealism, leaving only a fleeting series of states of consciousness, if we do not assume the existence of a system of "things in themselves" (noumena), of which kineses and metakineses are the phenomenal manifestations. Whether the "things in themselves" in any sense resemble their phenomenal manifestations, we cannot say. It is as difficult philosophically to conceive that they can as it is practically to conceive that they do not. And since, whether they do or do not, the world we live in is phenomenal; since it is to phenomena that we have to adapt our conduct; since it is with phenomena that all our thoughts and emotions have reference; since the world we construct in mental symbolism is the world in which we live and move and have our being; it is not only convenient, but logically justifiable, to call this world of phenomena the really existing world for us human-folk and other sentient organisms.
As in the kinetic interneural system, or brain, so, too, in the metakinetic system, no modification of the metakinesis which is out of harmony with the existing metakinesis can be incorporated therewith. Such attempted modification is eliminated through incongruity.
In the lower stages of mental evolution, those which belong to the perceptual sphere, where the neuroses are closely connected with the life-preserving activities of the organism, the survival or non-survival of the system of neuroses is largely dependent on the fitness of the associated activities to the conditions of life. But in the higher stages of mental evolution, those which belong to the conceptual sphere, the connection of certain brain-neuroses with life-preserving motor-activities becomes less close and direct. The corresponding ideas, thoughts, and emotions become floated off into a more abstract region. Here the system of ideas, as such, that is to say, so far as they are removed from life-preserving activities, is determined mainly by the law of congruity. But there are several such systems. There are, indeed, as many systems as there are minds; but these may be classified in several distinct groups, which we may liken to genera and species. These are the various interpretations of nature, theories of things, and the like; the systems of ideas, thoughts, conceptions, emotions, beliefs, which, as we say, belong to us, each and all, and which determine to which metakinetic species we belong. These are the highest products of mental evolution; and among them there is, so to speak, a struggle, if not for existence, at any rate for prevalence. Which shall eventually prevail—a spiritual interpretation of nature, a material interpretation, a monistic interpretation, or other, who shall say? But, so far as we can judge, the winning species among systems of ideas and interpretations of nature are likely to be those in which the greatest number of ideas are fused into harmonious synthesis; in which all the ideas are congruous; and in which the abstract or conceptual ideas, when brought into contact with concrete or perceptual states of consciousness, are found to be in harmony and congruity therewith.