(3) Largely determined by the two groups of influences named above are the forces which represent the national character at any given time, the outcome of primitive race characteristics, food supply, speed and direction of industrial development, density of population, and the various other causes which enter in to determine efficiency of labour. The play of these natural and human forces in world-competition leads to such a settlement of different industries in different localities as yields the greatest net productiveness of labour in each part. § 11. But this world-competition, however free it may become, can lead to no finality, no settled appointment of industrial activity to the several parts of the earth. Setting aside all political and other non-economic motives, there are three reasons which render such local stability of industry impossible. There is first the disturbance and actual loss sustained by nature in working up the mineral wealth of the soil, and the flora and fauna sustained by it, into commodities which are consumed, and an exact equivalent of which cannot be replaced. The working out of a coal-field, the destruction of forests which reacts upon the elementary climatic influences, are examples of this disturbance. Secondly, there is the progress of industrial arts, new scientific discoveries applicable to industry. There is no reason to believe that human knowledge can reach any final goal: there is infinity alike in the resources of nature and in the capacity of the development of human skill. Lastly, as human life continues, the art of living must continually change, and each change alters the value attached to the several forms of consumption, and so to the industrial processes engaged in the supply of different utilities. New wants stimulate new arts, new arts alter the disposition of productive industry, giving value to new portions of the earth. Ignoring those new material wants which require new kinds of raw material to be worked up for their satisfaction, the growing appreciation of certain kinds of sport, the love of fine scenery, a rising value set upon healthy atmosphere, are beginning to exercise a more and more perceptible influence upon the localisation of certain classes of population and industry in the more progressive nations of the world.