(i) If the bulk of all valuable land-parcels be capital, as it is, then one might expect beforehand to find _a law of diminishing returns_ from such lands, agricultural labor and skill remaining the same; because, all capital is tools made such by the expenditure of human efforts on changeable material, and then by the practice of _abstinence_, and tools from their very nature are always wearing out. Increase of efforts in connection with any form of capital unimproved by new inventions and uninvigorated by fresh skill, though they may indeed increase the aggregate return, cannot, for the reason just given, _secure an increase proportioned to the increase of the efforts_. The English writers generally, and Mr. Ricardo in particular, justly lay much stress on this proposition, although they have not taken lands to be capital, and have proven the law of diminishing returns in a different way from ours, and consequently have not set the propositions of land in their best and most ultimate relations. Their method of proving the law, however, is short and conclusive: If by doubling the efforts upon a piece of land, double the produce could be secured, and by quadrupling it, quadruple, and so on, there would be no reason why any man should ever cultivate more than a square acre, or even a square rod. He has a strong motive to confine his culture to a small space, just so long as the amount of produce is in the ratio of the efforts expended, because there is less locomotion of tools and fertilizers and crops. The fact that he extends his culture from one acre to another, and then to distant acres, notwithstanding the inconvenience and expense of transportation, is an irrefragable proof of the proposition in question. Increase of agricultural efforts and expenditures on a given space of land will secure a larger amount of produce, but as a general law, _the increased amount will not be proportioned to the increased expenditure_. It is through this law of diminishing returns, that the Creator has secured the gradual occupation, by men, of almost the whole earth. There is a strong and natural tendency to leave the old acres to advance upon new, the old countries to emigrate to new, whenever the returns begin to bear a more unfavorable ratio to the labors bestowed. The farmer will advance from the first to the second acre as soon as he thinks that more produce can be obtained from it by a given amount of efforts than can be gotten by a like expenditure of additional efforts upon the first acre, allowance being made for the increased inconvenience; and so, cultivation has gradually extended itself and men have become dispersed over the whole earth. Other principles leading to dispersion have undoubtedly co-operated, but this is the fundamental one, operative at all times, changing the course of population, and consequently of empire.