672 POLITICAL ECONOMY only then because land is not unlimited in quantity and uniform in quality, and because in the progress of population land of an infe- rior quality or less advantageously situated is called into cultivation, that rent is ever paid for the use of it. When in the progress of society land of the second degree of fertility is taken into cultivation, rent immediately commences on that of the first quality ; and the amount of that rent will depend on the difference in the quality of these two portions of land. When land of the third quality is taken into cultivation, rent immediately com- mences on the second, and it is regulated as before by the difference in their respective productive powers. At the same time the rent of the land of the first quality will rise, for that must always be above the rent of the second, by the difference between the produce which they yield with a given quantity of cap- ital and labor. " The most fertile and favora- bly situated land will be first cultivated, and the exchangeable value of its produce will be adjusted in the same manner as the exchange- able value of all other commodities, by the total quantity of labor necessary in various forms, from first to last, to produce it, and bring it to market. When land of an inferior quality is taken into cultivation, the exchange- able value of raw produce win rise, because more labor is required to produce it." " This," says one of Ricardo's followers, "is the fun- damental theorem of the science of value, and the clue which unravels the laws that regu- late the distribution of wealth." By reason of these theories of rent and value, if in accor- dance with the facts, the landlord would be en- abled to command a steadily increasing rent as the yield per acre declined, until he absorbed the entire product of the land ; and food would as steadily increase in cost as population in- creased. Starvation and wretchedness could not fail to be the lot of the mass of mankind under such a condition of things. These theo- ries seemed to aid in accounting for the Mal- thusian principle of population, and they at once took their positions as logically anterior to that doctrine, and became the foundation of the system now known as Ricardo-Malthu- sianism. In 1825 Samuel Bailey, author of " Essays on the Formation and Publication of Opinions," published U A Critical Dissertation on the Nature, Measure, and Causes of Value," in which he attacked Ricardo's theory of value. In 1821-'2 James Mill published " Elements of Political Economy," which is to some extent a statement and abstract elaboration of some of the doctrines of Adam Smith and Ricardo in regard to production and distribution, and those of Malthus respecting population. One of the most widely known writers on political economy and statistics for the last generation was J. R. McCulloch, who prepared the article for the supplement to the "Encyclopaedia Bri- tannica," a separate edition of which appeared in 1825, and which has since passed through several editions, the last in 1864 under the title of " The Principles of Political Economy, with some Inquiries respecting their Appli- cation, and a Sketch of the Rise and Progress of the Science," " McCulloch," says Colwell, " belongs neither to the school of Say, nor to the still more refined and strict school of Tracy, Rossi, and Senior. He persists in considering all the topics of political economy from a prac- tical point of view. He speaks of a science, it is true, but only in that popular sense in which men speak of the science of politics, which is a very different sense from that in which it is employed by Rossi, Senior, and J. S. Mill." In the " Encylopaadia Metropoli- tana" in 1835, and subsequently in a separate form, appeared " Political Economy " by Nas- sau W. Senior, professor in the university of Oxford ; the subject being, by the plan of the "Encyclopaedia," classed as among the pure sciences. But the author of this treatise failed to confine his investigations strictly within these bounds. " We propose in the following treatise," he says in opening, " to give an out- line of the science which treats of the nature, the production, and the distribution of wealth. To that science we give the name of political economy." He insists too on limiting his in- quiries to these subjects as the only true and legitimate ones, and adds that political econo- my does not treat of "happiness, but wealth." He even declines to examine into the effects upon society of the possession of wealth, what distribution is most desirable, or what are the means by which any peculiar distribution can be carried into effect by legislation. All of these questions are " of great interest and diffi- culty, but no more form part of the science of political economy, in the sense in which we use that term, than navigation forms part of the science of astronomy." The premises of the political economist he regards as consist- ing " of a few general propositions, the result of observation or consciousness, and scarcely requiring proof or formal statement, which almost every man, as soon as he hears them, admits as familiar to his thoughts, or at least as included in his previous knowledge ; and his inferences are nearly as general, and, if he has reasoned correctly, as certain as his prem- ises." The fundamental propositions in po- litical economy Mr. Senior thus states : 1, every man desires to obtain additional wealth with as little sacrifice as possible ; 2, the population of the world, or in other words the number of persons inhabiting it, is limited only by moral and physical evil, or by the fear of a deficiency of those articles of wealth which the habits of the individuals of each class of its inhabitants lead them to require ; 3, the powers of labor, and of the other instruments which produce wealth, may be indefinitely increased by using their products as the means of further produc- tion ; 4, agricultural skill remaining the same, additional labor employed on the land within a given district produces in general a less propor-
