372 POLITICAL ECONOMY discussion to which it gave rise, it remains a matter of some difficulty to discover what solid contribution he has made to our knowledge, nor is it easy to ascertain precisely what practical precepts, not already familiar, he founded on his theoretic principles. This twofold vagueness is well brought out in his celebrated correspondence with Senior, in the course of which it seems to be made appar ent that his doctrine is new not so much in its essence as in the phraseology in which it is couched. He himself tells us that when, after the publication of the original essay, the main argument of which he had deduced from Hume, Wallace, Smith, and Price, he began to inquire more closely into the subject, he found that much more had been done" upon it "than he had been aware of." It had " been treated in such a manner by some of the French economists, occasionally by Montesquieu, and, among our own writers, by Dr Franklin, Sir James Steuart, Mr Arthur Young, and Mr Townsend, as to create a natural surprise that it had not excited more of the public attention." "Much, however," he thought, "re mained yet to be done. The comparison between the increase of population and food had not, perhaps, been stated with sufficient force and precision," and "few inquiries had been made into the various modes by which the level " between population and the means of subsist ence " is effected." The first desideratum here mentioned the want, namely, of an accurate statement of the rela tion between the increase of population and food Malthus doubtless supposed to have been supplied by the celebrated proposition that " population increases in a geometrical, food in an arithmetical ratio." This proposition, however, has been conclusively shown to be erroneous, there being no such difference of law between the increase of man and that of the organic beings which form his food. J. S. Mill is indignant with those who criticize Malthus s formula, which he groundlessly describes as a mere "passing remark," because, as he thinks, though erroneous, it sufficiently suggests what is true ; but it is surely important to detect unreal science, and to test strictly the foundations of beliefs. When the formula which we have cited is not used, other somewhat nebulous expressions are sometimes employed, as, for example, that " population has a tend ency to increase faster than food," a sentence in which both are treated as if they were spontaneous growths, and which, on account of the ambiguity of the word " tend ency," is admittedly consistent with the fact asserted by Senior, that food tends to increase faster than population. It must always have been perfectly well known that population will probably (though not necessarily) increase with every augmentation of the supply of subsistence, and may, in some instances, inconveniently press upon, or even for a certain time exceed, the number properly corre sponding to that supply. Nor could it ever have been doubted that war, disease, poverty the last two often the consequences of vice are causes which keep popula tion down. In fact, the way in which abundance, increase of numbers, want, increase of deaths, succeed each other in the natural economy, when reason does not intervene, had been fully explained by the Rev. Joseph Townsend in his Dissertation on the Poor Laws (1786), which was known to Malthus. Again, it is surely plain enough that the apprehension by individuals of the evils of poverty, or a sense of duty to their possible offspring, may retard the increase of population, and has in all civilized com munities operated to a certain extent in that way. It is only when such obvious truths are clothed in the techni cal terminology of " positive " and " preventive checks " that they appear novel and profound ; and yet they appear to contain the whole message of Malthus to mankind. The laborious apparatus of historical and statistical facts respecting the several countries of the globe, adduced in the altered form of the essay, though it contains a good deal that is curious and interesting, establishes no general result which was not previously well known, and is accord ingly ignored by James Mill and others, who rest the theory on facts patent to universal observation. Indeed, as we have seen, the entire historical inquiry was an after thought of Malthus, who, before entering on it, had already announced his fundamental principle. It would seem, then, that what has been ambitiously called Malthus s theory of population, instead of being a great discovery, as some have represented it, or a poisonous novelty, as others have considered it, is no more than a formal enunciation of obvious, though sometimes neglected, facts. The pretentious language often applied to it by economists is objectionable, as being apt to make us forget that the whole subject with which it deals is as yet very imperfectly understood the causes which modify the force of the sexual instinct, and those which lead to variations in fecundity, still awaiting a complete investiga tion. It is the law of diminishing returns from land (of which we shall hear more hereafter), involving as it does though only hypothetically the prospect of a continuously in creasing difficulty in obtaining the necessary sustenance for all the members of a society, that gives the principal importance to population as an economic factor. It is, in fact, the confluence of the Malthusian ideas with the theories of Eicardo, especially with the corollaries which the latter, as we shall see, deduced from the doctrine of rent (though these were not accepted by Malthus), that has led to the introduction of population as an element in the discussion of so many economic questions in recent times. Malthus had undoubtedly the great merit of having called public attention in a striking and impressive way to a subject which had neither theoretically nor practically been sufficiently considered. But he and his followers appear to have greatly exaggerated both the magnitude and the urgency of the dangers to which they pointed. 1 In their conceptions a single social imperfection assumed such portentous dimensions that it seemed to overcloud the whole heaven and threaten the world with ruin. This doubtless arose from his having at first omitted altogether from his view of the question the great counteracting agency of moral restraint. Because a force exists, capable, if unchecked, of producing certain results, it does not follow that those results are imminent or even possible in the sphere of experience. A body thrown from the hand would, under the single impulse of projection, move for ever in a straight line ; but it would not be reasonable to take special action for the prevention of this result, ignor ing the fact that it will be sufficiently counteracted by the other forces which will come into play. And such other forces exist in the case we are considering. If the inherent energy of the principle of population (supposed everywhere the same) is measured by the rate at which numbers increase under the most favourable circumstances, surely the force of less favourable circumstances, acting through prudential or altruistic motives, is measured by the great difference between this maximum rate and those which are observed to prevail in most European countries. Under a rational system of institutions, the adaptation of numbers to the means available for their support is effected by the felt or anticipated pressure of circumstances and the fear of social degradation, within a tolerable degree of approximation to what is desirable. To bring the result nearer to the just standard, a higher measure of 1 Malthus himself said, " It is probable that, having found the bow bent too much one way, I was induced to bend it too much the other
in order to make it straight."