In all countries which have passed beyond a very early stage in the progress of agriculture, every increase in the demand for food, occasioned by increased population, will always, unless there is a simultaneous improvement in production, diminish the share which on a fair division would fall to each individual. An increased production, in default of unoccupied tracts of fertile land, or of fresh improvements tending to cheapen commodities, can never be obtained but by increasing the labor in more than the same proportion. The population must either work harder or eat less, or obtain their usual food by sacrificing a part of their other customary comforts. Whenever this necessity is postponed, it is because the improvements which facilitate production continue progressive; because the contrivances of mankind for making their labor more effective keep up an equal struggle with Nature, and extort fresh resources from her reluctant powers as fast as human necessities occupy and engross the old. From this results the important corollary, that the necessity of restraining population is not, as many persons believe, peculiar to a condition of great inequality of property. A greater number of people can not, in any given state of civilization, be collectively so well provided for as a smaller. The niggardliness of nature,(140) not the injustice of society, is the cause of the penalty attached to over-population. An unjust distribution of wealth does not even aggravate the evil, but, at most, causes it to be somewhat earlier felt. It is in vain to say that all mouths which the increase of mankind calls into existence bring with them hands. The new mouths require as much food as the old ones, and the hands do not produce as much. After a degree of density has been attained, sufficient to allow the principal benefits of combination of labor, all further increase tends in itself to mischief, so far as regards the average condition of the people; but the progress of improvement has a counteracting operation, and allows of increased numbers without any deterioration, and even consistently with a higher average of comfort. Improvement must here be understood in a wide sense, including not only new industrial inventions, or an extended use of those already known, but improvements in institutions, education, opinions, and human affairs generally, provided they tend, as almost all improvements do, to give new motives or new facilities to production.