CHAPTER XII.OF THE LAW OF THE INCREASE OF PRODUCTION FROM LAND.
§ 1. Land differs from the other elements of production, labour and capital, in not being susceptible of indefinite increase. Its extent is limited, and the extent of the more productive kinds of it more limited still. It is also evident that the quantity of produce capable of being raised on any given piece of land is not indefinite. This limited quantity of land, and limited productiveness of it, are the real limits to the increase of production.
That they are the ultimate limits, must always have been clearly seen. But since the final barrier has never in any instance been reached; since there is no country in which all the land, capable of yielding food, is so highly cultivated that a larger produce could not (even without supposing any fresh advance in agricultural knowledge) be obtained from it, and since a large portion of the earth's surface still remains entirely uncultivated; it is commonly thought, and is very natural at first to suppose, that for the present all limitation of production or population from this source is at an indefinite distance, and that ages must elapse before any practical necessity arises for taking the limiting principle into serious consideration.
I apprehend this to be not only an error, but the most serious one, to be found in the whole field of political economy. The question is more important and fundamental than any other; it involves the whole subject of the causes of poverty, in a rich and industrious community: and unless this one matter be thoroughly understood, it is to no purpose proceeding any further in our inquiry.