may be drawn from this discussion. First, each nation should be regarded as following a regular life course of definite ages, in which it is influenced at all times by the combined effect of the geographical factors of its environment. Second, from the proper valuation of these controlling factors it is possible in any stage of evolution to measure the real strength of a nation. Finally, every nation will arrive eventually at a stage where its physical surroundings set a limit to further development, materially, though not necessarily in culture. It may be expected that each nation as it arrives at this later stage in its existence will exhibit the spectacle of a static population, and such a nation may be said to have attained its full maturity—that is a condition of practically perfect adjustment between national opportunity and national development. France may be taken as an example of a nation which has reached, earlier than any of the others, this stage of full maturity.
It may even be that in individual cases, as perhaps in Germany and Japan, the temporary operation of one or two factors, as coal and some useful minerals, have already induced a condition of development which will necessitate subsequent readjustments, even to the point of actual decadence. A parallel condition might also arise through the misuse and consequent destruction of those national opportunities which should be permanent, as through soil erosion and the destruction of water power by deforestation. Wherever, by one means or the other, the basis for maintaining the national existence is materially lessened or destroyed, the nation must be regarded as old, or physically decadent, having exhausted the forces with which it was naturally endowed, just as in the old age of the human being, it is the breaking down of the individual physical endowment which marks the decline.
This inevitable adjustment of the nations of the world to their environments seems to call for relative decadence, like that of Holland since 1650, on the part of many nations holding a more or less prominent place to-day, especially so in the case of those of small area and restricted opportunity: and a corresponding rise, both relative and absolute, in most of the large units, which, in most cases, are still in the early, or young stages of their national evolution. In this latter group Russia, perhaps, is the most striking example, while the United States is somewhat farther along toward the stage of maturity: it might be described as having passed its adolescence and beginning to feel its strength, while Russia has still to reach the adolescent stage of youth. Thus the great nation of to-day may in one case be the great nation of to-morrow; in another case not. The real measure of fitness lies in the relation of each individual nation to the physical factors by which its evolution and its strength are determined.