Nothing but increase of food will permanently increase population, and where there is food the increase will reach up to it. In those parts of Africa that have furnished the Western slave supplies, there has been no discernible gap from the “hundred years’ exportation of negroes which has blackened half America.”[207] Even in Egypt, where there is a striking contrast between natural fertility and human lethargy, the cause is not any deficiency in the principle of increase. It is that property is insecure, the government being despotic and its exactions indefinite. It is not the want of population that has checked industry, but the want of industry that has checked population; and it is bad government that has occasioned the want of industry. “Ignorance and despotism seem to have no tendency to destroy the passion which prompts to increase, but they effectually destroy the checks to it from reason and forethought.... Industry cannot exist without foresight and security; the indolence of the savage is well known, and the poor Egyptian or Abyssinian farmer without capital, who rents land which is let out yearly to the highest bidder, and who is constantly subject to the demands of his tyrannical masters, to the casual plunder of an enemy, and not unfrequently to the violation of his miserable contract, can have no heart to be industrious, and, if he had, could not exercise that industry with success. Even poverty itself, which appears to be the great spur to industry, when it has once passed certain limits almost ceases to operate. The indigence which is hopeless destroys all vigorous exertion, and confines the efforts to what is sufficient for bare existence.[208] It is the hope of bettering our condition, and the fear of want rather than want itself, that is the best stimulus to industry; and its most constant and best directed efforts will almost invariably be found among a class of people above the class of the wretchedly poor.”[209] This passage repeats an idea expressed in every book of the essay.[210] Government can retard the increase of population both directly and indirectly, but can only advance it indirectly, namely, by encouraging industry, more especially agriculture. For example, industrious agriculture has made China capable of bearing a great population, though other causes of a more equivocal character have made it exceed its great capacities, and its excessive numbers are cut down by famine and child murder.[211] The Roman emperors found it impossible by legislation to promote the increase of the old Roman stock, because they found it impossible to restore the old Roman habits of industry, though believers in the superior populousness of ancient nations used to mistake their intentions for accomplished facts.