The standard of living is the index of the comfort and true prosperity of a nation. A high standard is a priceless heritage, which ought to be guarded at all cost. The United States has always prided itself on the high standard of living of its common people, but has not always understood on what that standard rests. The standard of living is the resultant of two great factors, the stage of the arts, and the ratio of men to land. It may be improved by bettering the methods of production and utilization of natural resources, or by reducing the ratio between men and land, _i.e._ by limiting the increase of population. It may be lowered either by a retrogression in the stage of the arts—something which can hardly be conceived of under our present civilization—or by an increase in the ratio between men and land. Both of these suppositions assume that the amount of land remains stationary. If large tracts of good land are made available by any means, it gives opportunity for a decided improvement in the standard of living, and if we can conceive of large areas of good land being actually lost, there would be an inevitable lowering in the standard. In point of fact, standards of living are much more likely to go up than down. The history of civilization has been that of increasing standards. A retrogression in the stage of the arts is not likely to take place on a large scale; neither is it probable that, other things being equal, men will increase their rate of reproduction, for the very reason that such an increase would involve a lowering in the standard of living.