‹Population has a tendency to keep on a level with the means of
subsistence.›
I cannot help remarking in passing that it is surprising that the
honour and responsibility of enunciating this principle, be it true
or false, should have been ascribed to Malthus. No writer on such
subjects since the days of Aristotle but has proclaimed it, and
frequently in the very same words.[86]
It is impossible to look around us on the aggregate of animated
beings without being convinced beyond doubt that nature has been more
engrossed with the care of species than of individuals.
The precautions which nature has taken to ensure the perpetuity of
races are remarkable; and among these precautions, a very noticeable
one is the profusion of germs or seeds. This superabundance
appears to be calculated in an inverse ratio to the sensibility,
intelligence, and power with which each species is endowed, to enable
it to resist destruction.
Thus, in the vegetable kingdom, the means of reproduction, by seeds,
cuttings, etc., which a single plant can furnish, are countless. One
elm (were all its seeds to take root) might give birth in a single
year to a million of trees. Why should this not actually happen?
Because all the seeds have not the benefit of the conditions which
vegetable life exacts, namely, space and nourishment. They are
destroyed; and as plants are destitute of sensibility, nature has
spared neither the means of reproduction nor those of destruction.
Animals, too, whose life is of a type akin to vegetable life,
reproduce themselves in immense numbers. Who has not wondered that
oysters, for instance, could multiply sufficiently to supply the
enormous consumption of them?
As we advance in the scale of animal life, we find that the means of
reproduction has been bestowed by nature with greater parsimony.
Vertebrated animals, especially the larger species, do not multiply
so quickly as others. The cow goes nine months, produces only
[p403] one calf, and must suckle it for some time. Yet even among
cattle the reproductive power surpasses what might be thought
absolutely necessary. In rich countries, such as England, France,
and Switzerland, the number of animals of this description increases
notwithstanding the enormous destruction of them; and had we
boundless pastures and prairies, there can be no doubt that we might
have both a still greater destruction and more rapid reproduction of
them. I should say that if nourishment and space were not limited, we
might have in a few years ten times more oxen and cows, even if we
consumed ten times more meat. The reproductive power of cattle, then,
even laying aside the extraneous consideration of the limitation of
space and nourishment, is far from being fully developed.
It is certain that the reproductive faculty in the human species
is less powerful than in any other, and it ought to be so. Man, in
the superior situation in which nature has placed him, as regards
intelligence and sympathy, ought not to be exposed to destruction in
the same degree as the inferior animals. But we are not to suppose
that ‹physically› he escapes from that law in virtue of which all
species have the faculty of multiplying to a greater extent than
space and nourishment permit.
I say ‹physically›, because I am speaking here only of the
physiological law.
There is a wide difference between the ‹physiological power› of
multiplying and ‹actual› multiplication.
The one is an absolute organic power when freed from all obstacle and
all limitation ‹ab extra›—the other is the effective resulting force
of this power combined with the aggregate of all the resistance which
limits and restrains it. Thus the power of multiplication of the
poppy may be a million a year, perhaps; but in a field of poppies the
actual reproduction may be stationary or even decrease.
It is this physiological law that Malthus essayed to reduce to a
formula. He inquired in what period of time a given number of men
would double, ‹if their space and food were unlimited›.
We can see beforehand that as this hypothesis of the ‹complete
satisfaction of all wants› is never realized in practice, the
‹theoretic› period must necessarily be shorter than any period of
‹actual› doubling which has ever been observed.
Observation, in fact, gives very different results for different
countries. According to the results obtained by M. Moreau de Jonnès,
taking for basis the actual increase of population, the period of
doubling would require—in Turkey, 555 years; in [p404] Switzerland,
227; in France, 138; in Spain, 106; in Holland, 100; in Germany, 76;
in Russia and in England, 43; and in the United States of America, 25
years, deducting the contingent furnished by immigration.
Now, what is the reason of such enormous differences? We have no
reason to think that they are the result of physiological causes.
Swiss women are as well formed and as prolific as American women.
We must conclude, then, that the absolute generative power is
restrained by external obstacles. And what proves this beyond doubt
is, that it is manifested as soon as circumstances occur to remove
these obstacles. Thus an improved agriculture, new manufactures,
some new source of local wealth, leads invariably in that locality
to an increase of population. In the same way, when a scourge like a
plague, or a famine, or war, destroys a great part of the population,
we immediately find that multiplication is more rapidly developed.
When an increase of population, then, is retarded, or stops, we find
that space and nourishment are awanting, or likely to be so; that it
has encountered an obstacle, or is scared by one.
This phenomenon, the announcement of which has brought down so much
abuse on Malthus, appears in truth beyond the reach of doubt.
If you put a thousand mice into a cage, with only as much provision
as is necessary for their daily sustenance, their number, in spite
of the acknowledged fecundity of the species, can never exceed a
thousand, or if it do, there will be privation and there will be
suffering,—both tending to reduce the number. In this case it would
be correct to say that an external cause limits, not the power of
fecundity, but the result of fecundity. There would assuredly be an
antagonism between the physiological tendency and the restraining
force, and the result would be that the number would be stationary.
To prove this, increase gradually the provision until you double it,
and you will very soon find two thousand mice in the cage.
And what is the answer which is made to Malthus? He is met with the
very ‹fact› upon which his theory is founded. The proof, it is said,
that the power of reproduction in man is not indefinite, is that
in certain countries the population is stationary. If the law of
progression were true, if population doubled every twenty-five years,
France, which had thirty millions of inhabitants in 1820, would now
have more than sixty millions.