THE POPULATION QUESTION
We have not in this volume discussed any of Spencer's contributions to
practical life, for the task of indicating his scientific position was
more than enough. Furthermore, his _Education_ is the best known of all
his works, and many of its suggestions are now realised in everyday
practice; his political recommendations are too debatable; and as to
ethical advice he has himself said: "The doctrine of Evolution has not
furnished guidance to the extent I had hoped. Most of the conclusions
drawn empirically are such as right feelings, enlightened by cultivated
intelligence, have already sufficed to establish." But there is one
practical suggestion to which we must refer, namely Spencer's
contribution to the population question.
"The Abundance of Life"--the title of a very suggestive essay by Prof.
Joly--is one of the great facts of Nature. The river of life is always
tending to overflow its banks. Hence, in part, the "Struggle for
Existence."
There are great differences in the number of offspring produced by
different kinds of organisms, and great differences in the
mortality-rate among the crowds of those produced. The rate of
reproduction depends primarily on the constitution of the organism, but
it also varies in response to external conditions, notably in relation
to the food-supply. Some organisms are intrinsically more reproductive
than others, thus the unicellular organisms, such as Bacteria and
Infusorians, which multiply by dividing into two or many units, head the
list; and, on the whole, it may be said that relatively simple creatures
multiply most rapidly, especially if their mode of reproduction, _e.g._,
the equipment of the germ-cells, is relatively simple and inexpensive,
and if the period required for reaching reproductive maturity is short.
But as we find very different reproductivity in animals and plants which
occupy the same grade of organisation, we are led to the conclusion,
which Weismann, for instance, has worked out, that the constitutional
capacity of producing many or few offspring has been regulated by
selection working throughout the ages, and is adapted to the particular
conditions of life. As the continuance of the race is an ideal aim,
which could not be present to the animal consciousness--not to speak of
the slumbering analogue of this in plants--all that we can say is that
in certain conditions variations towards greater fertility would be
relatively more successful because there were more of them to survive,
and that variations towards relative sterility would seal their own
doom. The survivors survived because they were many and capable of
producing many. Moreover it is possible in certain conditions that a
variation towards greater fertility may have been correlated with some
other variation, such as greater vigour on which the process of
selection could immediately operate. In any case, however, we may work
out the theory, the rate of reproductivity cannot be satisfactorily
interpreted without regarding it as in great part an adaptive character.
But while the rate of reproduction depends upon the constitution of the
individual organism, modifiable within variable limits by the direct
influence of food, warmth, and the like, the rate of increase or
decrease in an animal or plant population depends upon the wide and
complex conditions of the entire animate and inanimate environment. In
short, it is a function of the Struggle for Existence.
When there are no checks to prolific multiplication a single Infusorian
may become, in the course of a week, the ancestor of several millions,
and the same is true of a Bacterium within a day. Huxley has computed
that the progeny of single mother Aphis or green-fly, if they all lived
a charmed life, would in a few months literally outweigh the population
of China, which probably amounts to between two and three hundred
millions. If there were no checks to increase, a few pairs of cod-fish
and conger-eels would soon put an end to fishing and much else, by
making the North Sea solid. And apart from problematical cases, every
now and then, with locusts or voles, with rabbits in Australia, or
sparrows in America, we get a vivid glimpse of what a "spate" of life
may mean.
In the main, however, the river of life overflows its banks only locally
and temporarily. An adjustment of the abundance of life to the
limitations of subsistence is speedily effected in nature, and the flood
subsides. The "positive checks" of disease, starvation, lack of room,
internecine competition, increase of enemies, and so on, re-establish a
balance, though perhaps with a slightly changed centre of gravity. The
struggle for existence punctuates the increase of population.
In the history of mankind various aspects of the population question are
familiar. Whether we inquire into what is known of the history of
uncivilised races, or into present-day conditions in more or less
isolated communities and even in large countries, we read the story of
population-crises--of increase in numbers out-running the means of
livelihood. Among races in contact one often increases at a much more
rapid rate than the other, and we hear of "perils" of various colours.
Within a given race we find great differences in the fertility of
different sections or stocks and dangerous results impending. One nation
is troubled by its teeming millions, and another by its dwindling
birth-rate. The whole question is one of great biological interest and
human importance, and it is one to which Spencer had a very definite
contribution to make.
But before we consider Spencer's theory, it may be profitable to notice
what other suggestions have been made.
(_a_) _Malthusian._--In 1798, in his _Theory of Population_, Malthus
riveted the attention of all thoughtful men by seeking to establish the
induction that population tends to outrun the means of subsistence. In
its earliest form, his thesis was that population tends to increase in
geometrical ratio, while the means of subsistence increase only in
arithmetical ratio. So precise a statement cannot be justified, but
Malthus was right in insisting on the general fact that in certain
conditions and in certain stocks multiplication tends to exceed the
means of subsistence. His discussion of this thesis, and the conception
of "the struggle for existence" which he developed--for the phrase was
his--had a profound influence on many minds, including Spencer, Darwin,
and Wallace.
Malthus pointed out, with abundant concrete illustration, that the
increase of population is met by "positive checks," such as disease,
starvation, war, and infanticide, and that it may also be met by
"prudential checks," such as late marriage and moral control. His
practical corollary was that to avoid the "positive checks" which are
almost always appalling and pity-moving, we must develop the "prudential
checks," which tend to prevent further swelling of the population-tide.
"To a rational being the prudential check to population ought to be
considered as equally natural with the check from poverty and premature
mortality" (Malthus, 1806). The obvious objections are, that extended
celibacy or postponed marriage tends to increase of sexual vice; that
very late marriages are biologically and psychologically inadvisable,
tending for instance _on an average_ to increased mortality in
childbirth, to less fit children, and to a diminution of the happiness
of married life; and that moral control is apt to be most exercised
where it is least needed, namely among the more highly developed stocks,
and that it is a very uncertain check since great conjugal temperance
seems often to render conception the more certain.
(_b_) _Darwinian._--The Darwinian theory, that is the theory of Natural
Selection, supplied an important supplement to the Malthusian position.
For it pointed to the course of nature wherein the struggle for
existence has opened up the pathway of progress. Increase of population
brings about or accentuates the struggle for existence wherein the
relatively less fit are eliminated. Although this Natural Selection
works slowly it works surely, hence the Darwinian corollary is
practically nil, that is to say, a _laissez-faire_ policy. The obvious
objections are, that man as a rational and social being has a higher
standard than mere survival, and that a confidence in uncontrolled
natural selection is altogether optimistic. He cannot abrogate his task
of endeavouring, by rational selection, to accelerate what he believes
to be progressive evolution and to hinder degenerative change. Moreover,
it is not in him to stand by contemplating the mills of Nature grinding
slowly, ignoring the well-being of the individual in considering the
merely possible advancement of the species. And as a matter of fact he
is continually interfering with natural selection by introducing various
modes of what he believes to be rational selection.
(_c_) _Neo-Malthusian._--The general position of modern Malthusians may
be summed up in a few propositions. Population has a constant tendency
to outrun the means of subsistence; over-population is a fruitful source
of pauperism, ignorance, crime and disease; the positive or
life-destroying checks are cruel, and their reduction is in the line of
social progress; abstention from marriage is for normal organisms
unnatural and anti-social, postponement of marriage is also unnatural
and tends to vice and unfitness; the check that remains to be advocated
is "prudence _after_ marriage," and by this the Neo-Malthusians most
distinctly mean attention to methods which secure small families. So far
as these scientific checks imply control and conjugal temperance and
obviate or lessen misery, they commend themselves, but the obvious
objections are, that their use is often not without its physiological
risks, and that by annulling the responsibility of consequences, while
allowing the gratification of sexual appetites to continue, they may
have the result of increasing an already sufficiently intense sexuality,
of facilitating unchastity, and of exaggerating the tendency of marriage
to sink into "monogamic prostitution." On the other hand, it seems
probable that the transition from impulsive animalism to deliberate
regulation--somewhat mechanical though it be--would tend in some to
decrease not increase sexual intemperance. While the ideal surely is
that there should be a retention, throughout married life, of a large
measure of that self-control which must always form the organic basis of
the enthusiasm and idealism of lovers, it remains a fact that even
exemplary temperance does not obviate an unduly large family, and that
some form of Neo-Malthusian practice is in many cases the only
practicable suggestion--_pis aller_ though it be.
(_d_) _Spencer's Contribution._--In his keen analysis of the conditions
of multiplication,[20] Spencer showed that a species cannot be
maintained unless self-preservative and reproductive powers vary
inversely, and gave a physiological reason why these two powers cannot
do other than vary inversely. If we group under the term individuation
all those race-preservative processes by which individual life is
completed and maintained, and extend the term genesis to include all
those processes aiding the formation and perfecting of new individuals,
the result of the whole argument may be tersely expressed in the
formula--_Individuation and Genesis vary inversely_. And from this
conception important corollaries follow; thus, other things equal,
advancing evolution must be accompanied by declining fertility; again,
if the difficulties of self-preservation permanently diminish, there
will be a permanent increase in the rate of multiplication, and
conversely.
The next step was an inductive verification of these _a priori_
inferences, and here Spencer utilised a wealth of evidence drawn from a
wide survey of the animal and vegetable world. He measured individuation
by amount of growth, degree of development, and fullness of activity,
and his result always was that genesis and individuation vary inversely.
To the question: How is the ratio established in each special case?
Spencer answered: By Natural Selection. According to the particular
conditions of the species, natural selection determines whether the
quantity of matter spared from individuation for genesis be divided into
many small ova or a few large ones; whether there shall be small broods
at short intervals or larger broods at longer intervals; or whether
there shall be many unprotected offspring, or a few carefully protected
by the parent. In other words, natural selection determines the
particular form which the antithesis between individuation and genesis
will take. Finally, Spencer introduced the following qualification. If
time be left out of account, or if species be considered as permanent,
then the inverse ratio between individuation and genesis holds
absolutely, but each advance in individual development implies an
economy: the advantage must exceed the cost, else it would not be
perpetuated. The organism has an augmentation of total wealth to share
between its individuation and its genesis, and though the increment of
individuation tends to produce a corresponding decrement of genesis,
this latter will be somewhat less than accurately proportionate. In
short, genesis decreases as individuation increases, yet not quite so
fast. If the species be evolving, the advance in individuation implies a
certain economy, of which a share may go to diminish the decrement to
genesis.
Spencer then extended his hard-won generalisation to the case of man, in
which, as everyone knows, very high individuation is associated with all
but the lowest rate of multiplication. The same antithesis is seen on
comparing different races or nations, or even different social castes or
occupations. Where there is relatively low individuation, or where
nutrition is in obvious excess of expenditure required to get it, there
high multiplication prevails. Reviewing the various possibilities of
progressive human evolution, he concluded that this must take place
mainly on the psychical side. Hence the corollary that the culture of
man's psychical nature constantly tends to diminish the rate of
fertility, and pressure of population, which Spencer regarded as the
main incentive to progress, tends to disappear as it achieves its full
effect. The acute pressure of population, with its attendant evils, thus
tends to cease as a more and more highly individuated race busies itself
with its increasingly complex yet normal and pleasurable activities,
its rate of reproduction meanwhile descending towards that minimum
required to make good its inevitable losses.
This was Spencer's contribution to the population question, and it is
one which suggests hope and action, and is in harmony with the growing
ideal of racial eugenics. "For it is obvious that the progress of the
species and of the individual alike is secured and accelerated whenever
action is transferred from the negative side of merely seeking directly
to repress genesis, to the positive yet indirect side of proportionally
increasing individuation. This holds true of all species, yet most fully
of man, since that modification of psychical activities in which his
evolution essentially lies, is _par excellence_ and increasingly the
respect in which artificial or rational comes in to replace natural
selection. Without therefore ignoring the latter, or hoping ever wholly
to escape from the iron grasp of nature, we yet have within our power
more and more to mitigate the pressure of population, and that without
any sacrifice of progress, but actually by hastening it. Since then the
remedy of pressure and the hope of progress alike lie in advancing
individuation, the course for practical action is clear--it is in the
organisation of these alternate reactions between bettered environment
(material, mental, social, moral) and better organism in which the whole
evolution of life is defined, in the conscious and rational adjustment
of the struggle into the culture of existence."[21]
FOOTNOTES:
[20] A summary of his argument is given in "The Evolution of Sex," by P.
Geddes and J. Arthur Thomson. Walter Scott, London. Revised edition,
1901.
[21] _Evolution of Sex._ Chapter xx.