The Law of Population
Twenty years had elapsed since the publication of Smith’s immortal work, without economics making any advance, when the appearance of a small anonymous volume, known to be the work of a country clergyman, caused a great sensation. Even after the lapse of a century the echo of the controversy which it aroused has not altogether passed away. At first sight one might be led to think that the book touches only the fringe of economics, seeing that it is chiefly a statistical study of population, or demography, as the science is called to-day. But this new science, of which Malthus must be regarded as the founder, was separated from the main trunk of economics at a much later date. Furthermore, we shall find that the influence of his book upon all economic theories, both of production and distribution, was enormous. The essay might even be considered a reply to that of Adam Smith. The same title with slight modification would have served well enough, and James Bonar wittily remarks that Malthus might have headed it An Essay on the Causes of the Poverty of Nations.
The attempt to explain the persistence of certain economic phenomena by connecting them with the presence of a new factor, biological in its character and differing in its origin both from personal interest and the mere desire for profit, considerably expanded the economic horizon and announced the advent of sociology. We know that Darwin himself acknowledged his indebtedness to the work of Malthus for the first suggestion of what eventually became the most celebrated scientific doctrine of the nineteenth century, namely, the conception of the struggle for existence and the survival of the fittest as one of the mainsprings of progress.
There is no necessity for thinking that the dangers which might result from an indefinite growth of population had not engaged the attention of previous writers. In France Buffon and Montesquieu had already shown some concern in the matter. But a numerous population was usually regarded as advantageous, and fear of excess was never entertained inasmuch as it was believed that the number of people would always be limited by the available means of subsistence.[291] This was the view of the Physiocrat Mirabeau, stated in his own characteristic fashion in his book L’Ami des Hommes, which has for its sub-title Traité de la Population. Such a natural fact as the growth of population could possess no terrors for the advocates of the “natural order.” But in the writings of Godwin this “natural” optimism assumed extravagant proportions. His book on Political Justice appeared in 1793 and greatly impressed the public. Godwin, it has been well said, was the first anarchist who was also a doctrinaire. At any rate he seems to have been the first to employ that famous phrase, “Government even in its best state is an evil.” His illimitable confidence in the future of society and the progress of science, which he thought would result in such a multiplicity of products that half a day’s work would be sufficient to satisfy every need, and his belief in the efficacy of reason as a force which would restrain personal interest and check the desire for profit, really entitles him to be considered a pioneer. But life having become so pleasant, was there no possibility that men might then multiply beyond the available means of subsistence? Godwin was ignorant of the terrible intricacies of the problem he had thus raised, and he experienced no difficulty in replying that such a result, if it ever came to pass, must take several centuries, for reason may prove as powerful in controlling the sexual instinct as in restraining the desire for profit. Godwin even goes so far as to outline a social State in which reason shall so dominate sense that reproduction will cease altogether and man will become immortal.[292]
Almost at the same time there appeared in France a volume closely resembling Godwin’s, entitled Esquisse d’un Tableau historique des Progrès de l’Esprit humain, written by Condorcet (1794). It displays the same confidence in the possibility of achieving happiness through the all-powerful instrumentality of science, which, if not destined actually to overcome death, was at least going to postpone it indefinitely.[293] This optimistic book, written by a man who was about to poison himself in order to escape the guillotine, cannot leave us quite unmoved. But, death abolished, Condorcet finds that he has to face the old question propounded to Godwin: “Can the earth always be relied upon to supply sufficient means of subsistence?” To this question he gives the same answer: either science will be able to increase the means of subsistence or reason will prevent an inordinate growth of population.
It was inevitable, in accordance with the law of rhythm which characterises the movements of thought no less than the forces of nature, that such hasty optimism should provoke a reaction. It was not long in coming, and in Malthus’s essay we have it developed in fullest detail.
To the statement that there are no limits to the progress of mankind either in wealth or happiness, and that the fear of over-population is illusory, or at any rate so far removed that it need cause no apprehension, Malthus replied that, on the contrary, we have in population an almost insurmountable obstacle, not merely looming in the distant future, but pressing and insistent[294]—the stone of Sisyphus destined to be the cause of humanity’s ceaseless toil and final overthrow. Nature has planted an instinct in man which, left to itself, must result in starvation and death, or vice. This is the one fact that affords a clue to men’s suffering and a key to the history of nations and their untold woes.
Everyone, however little acquainted with sociological study, knows something of the memorable formula by which Malthus endeavoured to show the contrast between the frightful rapidity with which population grows when it is allowed to take its own course and the relative slowness in the growth of the means of subsistence. The first is represented by a geometrical series where each successive number is a multiple of the previous one. The second series increases in arithmetical progression, that is, by simple addition, the illustration being simply a series of whole numbers:
| 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
Every term corresponds to a period of twenty-five years, and a glance at the figures will show us that population is supposed to double every twenty-five years, while the means of subsistence merely increases by an equal amount during each of these periods. Thus the divergence between the two series grows with astonishing rapidity. In the table given above, containing only nine terms, the population figure has already grown to twenty-seven times the means of subsistence in a period of 225 years. Had the series been extended up to the hundredth term a numerical representation of the divergence would have required some ingenuity.
The first progression may be taken as correct, representing as it does the biological law of generation. The terms “generation” and “multiplication” are not used as synonyms without some purpose. It is true that doubling supposes four persons to arrive at the marriageable age, and this means five or six births if we are to allow for the inevitable wastage from infant mortality. This figure appears somewhat high to those who live in a society where limitation of the birth-rate is fairly usual. But it is certain that among living beings in general, including humankind, who are least prolific, the number of births where no restraint of any kind exists is really much higher. Women have been known to give birth to twenty or even more children. And there are no signs of diminishing capacity among the sexes, for population is still growing. In taking two as his coefficient Malthus has certainly not overstepped the mark.[295]
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