Such is the theory of rent, celebrated above all economic doctrines, and concerning which it might be said that no doctrine, not even that of Malthus, has ever excited such impassioned criticism. For this there are several reasons. In the first place, it led to an overthrow of the majesty of the “natural order” by simply depicting some of its gloomier aspects. Men had been led to believe that the “order” was for ever beyond challenge. Now, however, it seemed that if the new doctrine was true then the interests of the landed proprietors were opposed not only to those of every other class in the community—for sharing always begets antagonism—but also to the general interest of society as a whole. For what are the real interests of proprietors? First, that population and its demands should increase as rapidly as possible in order that men may be forced to cultivate new lands, and that these new lands should be as sterile as possible, requiring much toil and thus causing an increase in rents. Exhaustive labour bestowed upon the cultivation of land that is gradually becoming poorer and poorer would soon make the fortune of every landlord. As a class, proprietors have every interest in retarding the progress of agricultural science, a paradox which the slightest reflection will show to be true. Every advance in agricultural science must mean more products from the same amount of land and a check upon the law of diminishing returns, resulting in lower prices and reduced rents, since it would no longer be necessary to cultivate the poorer soils. In a word, since rent is measured by reference to the obstacles which thwart cultivation, just as the level of water in a pond is determined by the height of the sluice, everything that tends to lower this obstacle must reduce the rent. In mitigation of this charge it must, however, be noted that, taken individually, every proprietor is of necessity interested in agricultural improvement, because he may have an opportunity of benefiting by larger crops before the improvements have become general enough to lower prices and to push back the margin of cultivation. If every proprietor argued in this way, individual interest would finally cheat itself, to the advantage of the general public. But this is nothing to be very proud of.