Townsend,as to create a natural surprise that it had not excited more of the public attention.""Much,however,"he thought,"remained yet to be done.The comparison between the increase of population and food had not,perhaps,been stated withsufficient force and precision,"and "few inquiries had been made into the various modes by which the level"betweenpopulation and the means of subsistence "is effected."The first desideratum here mentioned --the want,namely,of anaccurate statement of the relation between the increase of population and that of food --Malthus doubtless supposed tohave 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 theincrease of man and that of the organic beings which form his food.J.S.Mill is indignant with those who criticise Malthus'sformula,which he groundlessly describes as a mere "passing remark,"because,as he thinks,though erroneous,it sufficientlysuggests what is true;but it is surely important to detect unreal science,and to test strictly the foundations of beliefs.Whenthe formula which we have cited is not used,other somewhat nebulous expressions are frequently employed,as,forexample,that "population has a tendency to increase faster than food,"a sentence in which both are treated as if they werespontaneous growths,and which on account of the ambiguity of the word "tendency,"is admittedly consistent with the factasserted by Senior,that food tends to increase faster than population.
It must always have been perfectly well known thatpopulation will probably (though not necessarily)increase with every augmentation of the supply of subsistence,and may,insome instances,inconveniently press upon,or even for a certain time exceed,the number properly corresponding to thatsupply.Nor could it ever have been doubted that war,disease,poverty --the last two often the consequences of vice --arecauses which keep population 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.JosephTownsend in his Dissertation on the Poor Laws (1786),which,we have seen,was known to Malthus.Again,it is surelyplain enough that the apprehension by individuals of the evils of poverty,or a sense of duty to their possible offspring,mayretard the increase of population,and has in all civilized communities operated to a certain extent in that way.It is onlywhen such obvious truths are clothed in the technical terminology of "positive"and "preventive checks"that they appearnovel and profound;and yet they appear to contain the whole message of Malthus to mankind.The laborious apparatus ofhistorical and statistical facts respecting the several countries of the globe,adduced in the altered form of the essay,thoughit contains a good deal that is curious and interesting,establishes no general result which was not previously well known,and is accordingly ignored by James Mill and others,who rest the theory on facts patent to universal observation.Indeed,aswe have seen,the entire historical inquiry was an afterthought of Malthus,who,before entering on it,had alreadyannounced his fundamental principle.
It would seem,then,that what has been ambitiously called Malthus's theory of population,instead of being a greatdiscovery,as some have represented it,or a poisonous novelty,as others have considered it,is no more than a formalenunciation of obvious,though sometimes neglected,facts.The pretentious language often applied to it by economists isobjectionable,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 acomplete investigation.(38)
It is the law of diminishing returns from land (of which more will be said hereafter),involving as it does --though onlyhypothetically --the prospect of a continuously increasing difficulty in obtaining the necessary sustenance for all themembers of a society,that gives the principal importance to population as an economic factor.It is,in fact,the confluence ofthe Malthusian ideas with the theories of Ricardo,especially with the corollaries which the latter,as we shall see,deducedfrom the doctrine of rent (though these were not accepted by Malthus),that has led to the introduction of population as anelement in the discussion of so many economic questions in recent times.
