§1. We have now successively considered each of the agents or conditions of production, and of the means by which the efficacy of these various agents is promoted. In order to come to an end of the questions which relate exclusively to production, one more, of primary importance, remains.

Production is not a fixed, but an increasing thing. When not kept back by bad institutions, or a low state of the arts of life, the produce of industry has usually tended to increase; stimulated not only by the desire of the producers to augment their means of consumption, but by the increasing number of the consumers. Nothing in political economy can be of more importance than to ascertain the law of this increase of production; the conditions to which it is subject: whether it has practically any limits, and what these are. There is also no subject in political economy which is popularly less understood, or on which the errors committed are of a character to produce, and do produce, greater mischief.

We have seen that the essential requisites of production are three — labour, capital, and natural agents; the term capital including all external and physical requisites which are products of labour, the term natural agents all those which are not. But among natural agents we need not take into account those which, existing in unlimited quantity, being incapable of appropriation, and never altering in their qualities, are always ready to lend an equal degree of assistance to production, whatever may be its extent; as air, and the light of the sun. Being now about to consider the impediments to production, not the facilities for it, we need advert to no other natural agents than those which are liable to be deficient either in quantity or in productive power. These may be all represented by the term land. Land, in the narrowest acceptation, as the source of agricultural produce, is the chief of them; and if we extend the term to mines and fisheries — to what is found in the earth itself, or in the waters which partly cover it, as well as to what is grown or fed on its surface, it embraces everything with which we need at present concern ourselves.

We may say, then, without a greater stretch of language than under the necessary explanation is permissible, that the requisites of production are Labour, Capital, and Land. The increase of production, therefore, depends on the properties of these elements. It is a result of the increase either of the elements themselves, or of their productiveness. The law of the increase of production must be a consequence of the laws of these elements; the limits to the increase of production must be the limits, whatever they are, set by those laws. We proceed to consider the three elements successively, with reference to this effect; or in other words, the law of the increase of production, viewed in respect of its dependence, first on Labour, secondly on Capital, and lastly on Land.

§2. The increase of labour is the increase of mankind; of population. On this subject the discussions excited by the Essay of Mr. Malthus have made the truth, though by no means universally admitted, yet so fully known, that a briefer examination of the question than would otherwise have been necessary will probably on the present occasion suffice.

The power of multiplication inherent in all organic life may be regarded as infinite. There is no one species of vegetable or animal, which, if the earth were entirely abandoned to it, and to the things on which it feeds, would not in a small number of years overspread every region of the globe, of which the climate was compatible with its existence. The degree of possible rapidity is different in different orders of beings; but in all it is sufficient, for the earth to be very speedily filled up. There are many species of vegetables of which a single plant will produce in one year the germs of a thousand; if only two come to maturity, in fourteen years the two will have multiplied to sixteen thousand and more. It is but a moderate case of fecundity in animals to be capable of quadrupling their numbers in a single year; if they only do as much in half a century, ten thousand will have swelled within two centuries to upwards of two millions and a half. The capacity of increase is necessarily in a geometrical progression: the numerical ratio alone is different.

To this property of organized beings, the human species forms no exception. Its power of increase is indefinite, and the actual multiplication would he extraordinarily rapid, if the power were exercised to the utmost.

It never is exercised to the utmost, and yet, in the most favourable circumstances known to exist, which are those of a fertile region colonized from an industrious and civilized community, population has continued, for several generations, independently of fresh immication, to double itself in not much more than twenty years.1 That the capacity of multiplication in the human species exceeds even this, is evident if we consider how great is the ordinary number of children to a family, where the climate is good and early marriages usual; and how small a proportion of them die before the age of maturity, in the present state of hygienic knowledge, where the locality is healthy, and the family adequately provided with the means of living. It is a very low estimate of the capacity of increase, if we only assume, that in a good sanitary condition of the people, each generation may be double the number of the generation which preceded it.

Twenty or thirty years ago, these propositions might still have required considerable enforcement and illustration; but the evidence of them is so ample and incontestable, that they have made their way against all kinds of opposition, and may now be regarded as axiomatic: though the extreme reluctance felt to admitting them, every now and then gives birth to some ephemeral theory, speedily forgotten, of a different law of increase in different circumstances, through a providential adaptation of the fecundity of the human species to the exigencies of society.2 The obstacle to a just understanding of the subject does not arise from these theories, but from too confused a notion of the causes which, at most times and places, keep the actual increase of mankind so far behind the capacity.

§3. Those causes, nevertheless, are in no way mysterious. What prevents the population of hares and rabbits from overstocking the earth? Not want of fecundity, but causes very different: many enemies, and insufficient subsistence; not enough to eat, and liability to be eaten. In the human race, which is not generally subject to the latter inconvenience, the equivalents for it are war and disease. If the multiplication of mankind proceeded only, like that of the other animals, from a blind instinct, it would be limited in the same manner with theirs; the births would be as numerous as the physical constitution of the species admitted of, and the population would be kept down by deaths.3 But the conduct of human creatures is more or less influenced by foresight of consequences, and by impulses superior to mere animal instincts: and they do not, therefore, propagate like swine, but are capable, though in very unequal degrees, of being withheld by prudence, or by the social affections, from giving existence to beings born only to misery and premature death. In proportion as mankind rise above the condition of the beasts, population is restrained by the fear of want rather than by want itself. Even where there is no question of star............