The Philosophy of Growth
I
GROWTH is a theme in which all are interested. Whether in agriculture or education, industry or politics, rate of growth is the criterion of health, vigor, and success. Growth is, indeed, our chief index of virility. Animals grow. Plants grow. Crystals grow. Ideas grow. This essay has grown. Valleys grow. They have youth, maturity, and old age. Towns grow. We are glad if our business grows. If growth, then, is a general principle of existence, especially of life and human affairs, there must be a philosophy of growth — if not, indeed, the philosophy of growth.
Growth is primarily a biological concept. Its meaning has been applied to social and metaphysical matters largely as a borrowed method of interpretation. Perhaps we may best elucidate our philosophy of growth by inquiring first into the biological connotations of the term.
When referring to living things, growth means more than simply increase in size. The cactus growing in the desert becomes larger during each day and diminishes in volume every night. The diurnal increment that compensates for the nocturnal shrinkage is not growth, but merely swelling. The stomata — breathing-pores — are open during the night, permitting the plant to lose water by vaporization more rapidly than it is absorbed. During the daytime they are closed, and the roots take in more water than evaporates from the aerial parts; hence the cactus swells.
And so with a college or university— the fact that it may be getting bigger buildings, bigger grounds, bigger classes, or even bigger professors, does not necessarily mean that it is growing. It may be only swelling; and the hour of shrinkage may not be remote. Enlargement alone is not growth.
Growth for the biologist includes not only cell-enlargement but cell-division as well; that is, in growth there is a multiplication of the units of structure in addition to an increase in volume. The woolen mill has not grown by the continued enlargement of the spinningwheel and loom to gigantic proportions, but rather by increase in the number of spindles and shuttles and carding-points, the units of which the mill is composed. Now, instead of one spindle on a spinning-wheel, we have a machine with hundreds of spindles operating simultaneously; instead of a hand carding-iron, there is a mechanism which cards the wool in great quantities. And so with a university, growth involves, not simply bigger classes, but more classes; not simply bigger departments, but more departments; not bigger athletes, but more students.
And yet even the rapid increase in the registration at our universities does not necessarily mean that they are growing. When a plant grows, its cells not only enlarge and divide, but they differentiate as well: their walls become thicker, or impregnated with some special substance; new internal cellorgans may be developed, such as plastids or vacuoles; the cell may change its shape; or its chemical composition may be distinctly altered. As the result of one or more of these changes, the cell becomes fitted for some special function in the plant
— for instance, conduction, storage, strengthening, protection, food-manufacture. Likewise in the animal during growth the primary embryonal cells differentiate into muscle fibres, nerve cells, cartilage, and so on. Differentiation is as fundamental a phase of growth in higher organisms as is cellenlargement or cell-division. If we have only these latter two occurring in multicellular beings without an accompanying differentiation, we have cancer, and not normal development. While we apply the term ‘growth’ to the spread of a cancer, it is in a sense a misnomer; for the cancer is headed straight for destruction, and has no measure of success as a goal of its existence. True growth in the higher plants and animals must involve differentiation.
Nevertheless, the growth of primitive organisms consists solely of increase in size and number of cells. They are entirely devoid of cellular differentiation. Each single isolated cell performs all of the functions of an entire organism. But in the course of organic evolution these primitive cells became associated together into clusters, colonies, and then simple multicellular units. Here, then, came the opportunity for specialization,— if not, indeed, the necessity for it,
— and differentiation came to be an essential accompaniment of growth.
Just so, in the evolution of human society, the family of the pioneer performed all the functions necessary for life. They raised their own cotton or wool, spun it into yarn, and wove their cloth; they produced their own food, hewed their own timber, collected their own herbs, taught their own children, and even said their own prayers. They were undifferentiated human beings. But with the advent of modern civilization we find specialization: the physician, the surgeon, the lawyer, the baker, and the crossword-puzzle maker.
Growth in industry is not simply expansion and duplication; it also involves specialization. It consists in a man learning how to run just one machine, to put just one bolt in the flivver. We are told that three generations are required to produce an expert weaver of the golden tapestries of Europe.
In the early days of a certain American university one man taught all of the natural history that was given. Then he secured an assistant to give instruction in plants, while he himself specialized on animals. Later he retained another student to teach about living animals, while he concerned himself with those of past ages. And so the departments of geology, zoölogy, and botany had their origin. To-day the last-named is represented by a plant-morphologist, a plant-ecologist, a plant-physiologist, and a plant-pathologist. A similar development took place in all our large institutions of higher education. Such is the growth of learning.
But the benefits of differentiation are not unaccompanied by its penalties. The law of compensation holds here as elsewhere. The cell of the Amœba or the Chroöcoccus divides and forms cells that are, as far as we can tell, exactly like itself. It never changes. If adverse conditions arise it simply rests until conditions are again favorable. It knows no natural death. Death can come to it only by accident, by extreme temperatures, chemicals, grinding, and so on. When, however, a cell becomes differentiated, as is the case with most cells of the higher plants and animals, it sooner or later loses its ability to divide again. It can no longer form more cells; its existence is therefore limited. It must sooner or later cease to exist as a cell. Such cessation of existence is death, and the approach to such cessation is senescence.
Our forefathers devoted much attention to the question of avoiding death: that is, of immortality. Religion was concerned primarily with holding out hopes of an after life. To-day we are giving relatively little thought to that old quest. Our churches are more concerned with rectifying the present life than with grappling for a future life. Even scientifically we have turned our attention toward postponing old age.
II
The growth period of an organism may be divided into three parts: juvenescence, maturity, and senescence. Senility is the ivory age, white with fixity and inflexibility. Maturity is the golden age, bright with deeds, hopes, and opportunities. Youth is the uranium age, emitting radioactive emanations that electrify the ambient medium. Juvenescence is a period of acceleration; maturity is a period of steady progress; and senescence is characterized by retardation.
Expressed geometrically, growth describes an S-shaped curve, the S being loose with its middle portion inclined slightly forward and not backward. The lower left portion, representing youth, is hyperbolic, becoming more and more abrupt as it approaches the vertex, at which it straightens out into the ascending line of maturity.
Youth is the plastic age. During it the cells that are on their way toward specialization may, if conditions become altered, dedifferentiate, becoming embryonal again; and then they can start off on a new line of differentiation. If, in mowing, a young ragweed is decapitated, its parenchymal cells dedifferentiate into meristematic cells again; and these set about forming a new top by redifferentiation into all the types of cells normally occurring therein. This later process we call regeneration. But, if the ragweed had been a little older, dedifferentiation, and hence regeneration, would have been impossible, for maturity would already have set in. The egg of a frog normally divides into two cells, each of which respectively gives rise to different tissues of the adult amphibian. But if we shake apart these two blastotneres each will give rise to a distinct frog; for the cells are still in their period of juvenescence, and have the ability to return to their original state and start development over again along new lines.
Dedifferentiation and regeneration are quite as characteristic of juvenescence in the psychological, moral, and social realms as in the physiological. On one day the child plays that he is a doctor, on the next that he is the driver of a grocery wagon. He can dedifferentiate and regenerate with great rapidity. We call this ‘imitation.’ As he enters upon youth these processes take place more slowly, and hence are fewer. He thinks one week, or one month, that he will study to be a preacher, and the next he is certain of becoming a football hero. We say that he is ‘establishing his ideals.’ When he goes to college it may take him a year or more to change his plans for life. Finally he finds himself at an age when dedifferentiation is no longer possible. Regardless of economic pressure or even of his own pleasure or pain, he is unable to make himself over. He has reached maturity. Morally he has experienced a similar change in flexibility. In Methodist terms, youth is the logical time for conversion. It is the opportunity which nature affords for adjustment to a changing world, for trial and error — or rather, for trial, error, retrial, and success. During the war the aniline-dye works of Germany readily dedifferentiated and were regenerated into munition plants. But our steel-ship building-yards had specialized too far; we could not make them over for the construction of wooden ships. They had entered upon maturity; and maturity is a period of forward movement and not of modification.
Personally, the period of maturity is the one which we all desire to extend as much as possible. We wish to reach it as early as we can, and to prolong it while life lasts. We are glad if we are told that our boy with a biologic age of five has a mental age of nine. We are sad if told that we ourselves, with a biologic age of fifty, have a mental age of ninety. As to how this latter may successfully be avoided, I know of no better plan than to study the personalities of men who have been thus successful.
But how shall we know when we pass from the age of maturity into that of senility? William James, in urging his students to diligence, told them that, if they kept at their studies, some fine morning they would wake up and find themselves educated. Professor James meant this to apply to the dawn of maturity. It has seemed to me far more applicable to the cessation of maturity and the dawn of senility.
I know some botanists — a very few — who do not care to frequent the library, for fear someone may find them reading something that they should already know; who do not enjoy going into the field with their students, for fear someone may bring them a plant that they cannot name; who avoid the laboratory for fear they may see some experiment that they cannot explain. Nor are such expressions of senility confined entirely to botanists. There are physicians who pose as knowing everything in the medical literature about your case, preachers who never pick up the Atlantic Monthly, and farmers who never read the Agricultural Bulletins. Such men have awakened and found themselves fearfully and phobiously ‘educated’; in fact, they are already far along in the solidivory stage of senility. But those botanists who spend their days in the field, or their nights in the laboratory, or are reading in the library when they might be playing golf, are still sound asleep in the golden oblivion of maturity. May they sleep peacefully, and may morning never come!
Senescence is not a second childhood. It is the reverse rather than the repetition of juvenescence. Senescence describes a receding hyperbolic curve, setting in quickly, but advancing at a slower and slower rate until it merges imperceptibly into death.
Death is not the sudden-end point that we have too often thought it to be. It is rather a gradual process of transition. Hundreds of people every day lose consciousness, only to be revived again. The loss of consciousness is by no means a criterion of death; for respiration still continues. Consciousness may vanish and breathing cease, yet many drowned persons are thereafter resuscitated; for heart action may still be going on, and death has not occurred. But even the stopping of the heartbeat is no longer to be regarded as the absolute index of death; for science has found a way to stimulate that into action again, if there are no organic obstacles. Even after the heart is forever still the cells of the body remain alive, some of them for many days; and they may be kept alive in a cool sterile place for even months or years. Osterhout has found, by the use of technical chemical and electrical tests, that cell death is, likewise, by no means sudden. It too is a gradual transition from reversible to irreversible reactions. Death is thus simply a projection of senility, and not its termination.
The physiology of senility is one of the most potent questions in biology to-day. Microorganisms are found to grow at a slower and slower rate if left on the same nutrient media. If removed to other media of the same nutrient composition, they resume rapid cell-division. The old media had become stale with the waste products of their metabolism. Metchnikoff used this idea as a basis for his theory of senility in humans. He believed that by proper diet the waste products of our bodies could be removed, and maturity thus be prolonged indefinitely. But Metchnikoff and his theory have now passed on. DeVries early pointed out a decrease in acidity of the cell sap with advancing age; and Walter claims that a reduction in the water content of the tissues occurs, which accounts for the shriveled appearance of aged people, also noticeable in senile individuals of many types of plants and animals. Robertson regards senescence as the inevitable result of the law of mass action. The rate of a reaction and its direction are determined by the ratio of the materials available for consumption to the products of the transformation. In juvenescence the materials far exceed the products; in senescence the products have accumulated until in many places within the organism the direction of the reactions is reversed. The net result is thus a retardation of the chemical changes which support life. Russo and Lepeschkin have developed the theory that is perhaps most generally accepted by biologists at the present time, as to the fundamental basis of senility. They hold that there is a gradual transformation of the living substance of higher organisms during the life-span of an individual, from a liquid state to that of a gel. Primitive unicellular organisms have their living substance permanently in a state of fluidity; they therefore know no senescence. The embryonal cells of higher organisms are likewise in this state, but during juvenescence they become more and more viscid; during maturity their protoplasm becomes still more jelly-like; and in senility it takes on the firmness of a gel, which later merges into the crystallinity of death. This conclusion is corroborated by the findings of Haberlandt, which reveal that the otoliths in the organs of equilibrium of the ear, and the statoliths in the organs of equilibrium of the root, settle through the liquid in these structures at a slower and slower rate as age advances, indicating an increase in its viscosity. The vulgar expression ‘hard-boiled’ is perhaps more apropos than has in the past ordinarily been admitted.
III
Sexual reproduction is nature’s method of conquering old age. In the higher plants and animals a few cells are set aside for this purpose. In the past we have been in the habit of thinking of these sex cells as persisting in the adult organism in an undifferentiated condition, like the meristematic cells in the bud of a tree or shrub. It may be, however, that they are just as highly differentiated and have reached the same stage of senescence as have the muscle fibres or sieve tubes. But if so they have the ability, upon fusion, to return to the undifferentiated state and begin juvenescence once more.
Many organisms have the ability to produce new generations without resort to sexuality. But it may very well be that such methods of reproduction are only temporary expedients. It is the general impression among horticulturists that, if the potato is propagated vegetatively for many generations, the strain will degenerate. Periodic sexual reproduction reëstablishes virility. This perhaps may more than any other fact explain the prevalence and persistence of sexuality among higher organisms. It is accomplished at great expense of time in the pine trees, requiring a number of years. It is carried on at great expense of substance and energy, involving the construction of elaborate sex-organs of two distinct types, male and female. Furthermore, it involves great hazards, necessitating the production of a multiplicity of sex cells in order that two of them, unlike each other, may eventually get together. In the liverworts, for instance, a naked sperm must swim for a relatively great distance through external water in order that it shall reach the egg, dependent for the most part upon fortuity to give it direction. For all this price there must be some satisfactory recompense, else the organisms that have paid it would have lost out as helpless competitors in the struggle for existence. Its advantage seems to lie in the fact that it returns some cells, at least, to the state of juvenescence, and thereby conquers the otherwise unavoidable consequences of differentiation — namely, senility and death.
Temporary substitutes for sexual reproduction may be found in parthenogenesis, vasectomy, or grafting; but it may be questioned whether they will stand the test of time. Benedict finds that the relative vein-tissue of grape leaves becomes greater and greater as the age of the vine advances, regardless of whether it remains on the same root system or has been grafted repeatedly to fresh stocks. Eventually the leaves become inefficient, due to the reduction in the extent of the manufacturing area; and the vine would become extinct, were it not for the production of seeds by sexual cells.
IV
But senescence is not the only penalty which the higher organism pays for specialization. Differentiation also means diminution in adaptive ability. The most adaptable organisms on the earth are by no means those which are most highly differentiated. On the other hand, the ones that we deign to call the lowest forms of life are in many ways the most successful. They have, in fact, lived on the earth in their present form longer than any other beings. Witness the bacteria consisting of single isolated cells or short rows of cells. Many of them are non-sporeforming, that is, they have no specialized cells even for dormancy. Yet bacteria in multitudes attack the human body — probably the most highly differentiated of organisms — and each year cause hundreds of the latter to succumb to their onslaughts. Conquer the bacteria, and you have almost eliminated the need for a medical profession.
Perhaps even more primitive than the bacteria are the blue-green algæ, a group of organisms that manufacture their own food. Some of them grow during the spring in seeps on the rocky walls of abandoned quarries, living an aquatic life. Then the moisture evaporates, and they spend an aerial existence for weeks without change of form, baked by the intense rays of a summer sun. When autumn comes they are covered with water once more. This later freezes, and they experience sub-zero temperatures without alteration. As ‘red snow,’ some of their relatives blow about unharmed on the frosty fields of the frozen North. Others live in pools high on the rocks along the seacoast. These are filled one day by storm-tossed waves; and then, during the clear quiet days that follow, the water slowly evaporates, leaving the residue to thicken into a brine and even to form a supersaturated solution. Still the micro-plants persist. Suddenly there comes a beating rain; the salt is for the most part dashed out of the pool, and fresh water takes its place; yet the alga goes on, unharmed by these changes in osmotic pressure.
VOL. 136 — NO. 4 D
Specialization means lack of adaptability. The undifferentiated alga on the quarry rocks adapts itself to extremes of temperature and extremes of moisture; the leaf growing on the tree near by may wither in the dry blasts of summer, and it drops with the first frost. During the war hundreds of teachers of German in our high schools found themselves out of employment. The younger of them were able to dedifferentiate and take up Spanish or French. The others had to suffer the consequences of their specialization.
V
It thus appears that enlargement, multiplicity, and specialization are not alone adequate for the highest expressions of growth. Industry does not evaluate specialization as the acme of success. It pays most in salaries, in honor, and in publicity to its executives, and not to its experts. Executives are not specialists; they are generals in the fullest sense of that word. Administrative ability involves a smattering of knowledge of a great many things, a grasp of general principles without attention to details. It is associated with the generalized type of mind; and industry pays more for it than it does for the critical student.
Our newspapers relate in extenso the doings of our political generals at the various international conferences, and rarely mention even the names of the experts, whose work is quite as important. Our military generals receive a cheer from the populace wherever they go, while the designer of a submarine-detector plods along, unnoticed in the crowd. Our scientists eke out a meagre existence, compared with the captains of industry who profit by their discoveries.
What, then, is the reason that executives are more valuable than experts?
Is it not that healthy growth consists not only in differentiation, but in mutual helpful interaction as well? The executive is not better paid because he knows more than the expert, but because he is presumably able to get other people to do more than is the expert. He is able to coördinate, to compromise, to coöperate, and to get those under him to coöperate.
Growth in unicellular organisms may consist simply of cell enlargement and cell division; but as soon as we have associations of differentiated cells there is introduced a fourth feature of growth — namely, cellular interaction. The external manifestations of growth are the resultants of the mutual interactions of the cells within. The neighboring cells of a tissue press and pull each other. Some tend to elongate more rapidly than others; and the actual rate of elongation of the tissue is the net consequence of a compromise. Cells also affect each other chemically. In extreme cases this takes the form of internal secretions, endocrine bodies, or hormones, as they are variously called, such as adrenalin, insulin, and pituitrin, which produce such marked physiological responses in human beings and in the higher animals. Quite comparable to these in behavior are the vitamines, which are constituents in food having definite physiological effect, especially upon the rate of development of the organism.
In the activity of all these special substances it is to be noted that very minute amounts produce very striking reactions. And so, in the interactions of social beings, the importance of an act is not to be judged by its own proportions, but by its consequences. It takes only the striking of a match to start a fire; only the pressing of an electric button to cause an explosion. A shake of the head or a shrug of the shoulders, by a person who is in a position to know, is but an incident; yet it may result in some worthy individual failing to receive an appointment that he would otherwise have obtained. Pettiness and personal antipathy may be small matters in themselves; nevertheless they may have consequences that eventually will upset our entire social well-being.
It is not sufficient that the highest forms of life have specialized cells; there must be specialized associations of cells. The muscle is such an association, directed toward mechanical movement; the leaf is another, directed toward food-formation. Not all of the cells of the muscle are muscle fibres; there are neurones and blood vessels as well. Not all of the cells of the leaf manufacture starch; there are protective cells, strengthening cells, and conductive cells. In the healthy growth of an organism, cellular interaction must be harmonious. And so, in the evolution of human society, we not only have teachers, sailors, and automobilemakers, but have college towns, ports, and Detroits. Not all of the persons in a college town are students or instructors; there must be some janitors and some cooks. The modern community is largely an association of specialists working together and dominated by some common interest.
The cells of unlike organisms also interact with eachother. In some cases this is an harmonious relationship, as when the alga and the fungus intermingle to form a lichen, the one supplying the food for both, while the other retains the water which both need. Symbiosis and commensalism are instances of interaction between individuals of different species with advantage to both. But not infrequently individual interaction between species constitutes parasitism. When the tubercle bacillus and the cells of the human body are brought into close proximity each attempts to destroy the other by the toxic substances which it emits. In some such relationships the cells of one organism may even devour those of the other. This is phagocytosis; and phagocytosis is the opposite of harmonious interaction.
The new internationalism must establish a symbiosis among nations, and not phagocytosis or parasitism. The great empire must not, like a phagocyte, pounce upon its weaker neighbors to devour them; neither must the smaller nation parasitically sap the substance of its more bulky brother. Constant compensating commercial intercourse, such as exists between Canada and our own country, is certain to culminate in the accomplishment of commensalism among commonwealths.
Within organisms the respective cells coöperate in a unified tendency to development. Due to disproportionate enlargement, division, or differentiation, there are minor stresses and strains set up within growing tissues. Usually these are not so pronounced as to disturb normal development, and are to be regarded as the inevitable sacrifices that one cell must make for another in order that progress may be accomplished. Occasionally these pressures and tensions may attain sufficient magnitude to push into the conscious realm as growingpains, and thus constitute a temporary disturbance. In rare instances they may prove destructive, as when the leaf stalk of a May apple is held for a day or so in a horizontal position, prevented from bending upward as it normally would. Upon being released, it curves over so quickly and so tightly that the surface tissues on the lower side are entirely disrupted. But on the whole the cells of the growing organism, far from consuming each other, live together in a state of mutual cooperation, accomplishing results that would otherwise be impossible.
And so with the body politic: minor frictions, jealousies, and ambitions are the normal unavoidable accompaniment of development. Occasionally growing-pains may thrust themselves into publicity in the form of strikes, bitter political contests, and K. K. K.’s. Rarely do they reach the proportion of revolutions, when destruction of life and property is the dire consequence. Not competition but coöperat ion is proving to be the watchword of successful social development. The obligate parasite that entirely consumes its host destroys itself also. Many a disease-producing organism has doubtless fallen by the way in the course of organic evolution, and for this very reason.
Industry is discovering that the same principle holds for its own progress. Capital is recognizing as never before the need of its harmonious articulation with labor, and labor is realizing that capital too is necessary for its welfare. The layman is becoming aware of his debt to science, and the scientist is conscious of his responsibility to the public. The producer must satisfy the consumer, and the consumer must compensate the producer. Children must receive the advice of their parents, and parents are bound to respect the liberties of their offspring. It is only by such mutual respect and coöperation that progress is possible.
Phagocytosis occurs in industry when a subordinate has nothing good to say about the executives over him; phagocytosis occurs also when a superior fails to recommend a helpful subordinate, in order that the latter may be retained without increased reward. It occurs when a subordinate seeks to displace a superior; it also occurs when a superior signs his name to the work of a subordinate without giving the latter proper credit for his contribution.
Mutual coöperation occurs in industry when the foreman criticizes his subordinates first privately, and only as a last resort, to the manager. Mutual coöperation in industry also occurs when the subordinate first submits his grievance to his immediate superior, and not to his colleagues or to the man higher up. It exists when the worker gives his best service, and when the executive does his best, to promote the pay and privileges of the employed.
VI
Growth, then, consists of four phases: enlargement, duplication, differentiation, and coöperation. No one, two, or three of these alone constitute growth. Enlargement alone tends to become swelling, intumescence, hyperplasia. In spite of the fact that we ordinarily regard gain in weight as an indication of good health, yet we are all aware of the objections to obesity. Despite the fact that Los Angeles with its several suburbs is proud of becoming a super-city, China and India have taught the world lessons in the perils of overpopulation. When business becomes too big it constitutes monopoly, endangering the rights and well-being of others. Rapid increase in size is possible by enlargement alone; but such growth is not conducive to stability. The mushroom pushes up out of the soil by cell enlargement exclusively. There is no accompanying celldivision to give its tissues compactness, and no accompanying differentiation to give them firmness and permanence. In metaphysical and social matters we must also be wary of mushroom methods of expansion.
Neither do enlargement and duplication together comprise growth in its highest expression. Such may entail only needless repetition, cancer, hypertrophy. Too many competitors are just as destructive to business as is monopoly. ‘Too many cooks spoil the broth’ and ‘Too many irons in the fire’ are just commonplace expressions for the dangers of duplication. Versatility may be only a polite expression for vacillation.
Nor do augmentation, multiplication, and specialization together form a complete basis for healthful development. Without harmony they may result in discord, phagocytosis, war. Harmony is the keystone in the arch of elaboration; without it the rest of the structure falls into chaos and ruin. Harmony between God and man is the basis of religion. Harmony between man and man is the basis of society. Normal healthy development, whether it be in plants, animals, or man, involves an harmonious regulation of multiplied and diversified expansion. Absence of harmony is disease and monstrosity. Sanity in the psychological realm is the consequence of the harmonious association and evaluation of ideas; the absence of harmony is obsession, perversion, and hallucination. In social, political, and industrial affairs love, peace, and prosperity are the results of the harmonious interaction of expansion, diversification, and compensation; the absence of harmony is cutthroat competition and war. Growth in whatever realm rests upon these universal principles of progress, for the universe is one and indivisible.