This is not saying, of course, that Malthus's theory may not have some elements of truth in it. Undoubtedly Malthus's theory does apply to stationary, non-progressive peoples, like savages and barbarians in certain stages of culture, and also perhaps to certain classes in modern society who fail to participate in modern social progress. But these lower classes or elements in human society are constantly decreasing, especially in America, where the tendency to individual improvement is so marked. Again, Malthus's theory, so far as it depends upon the economic law of diminishing returns in agriculture, has also certain elements of truth in it, and in so far as it merely asserts that the struggle for existence in human society is, in the last analysis, a struggle for food. Finally, Malthus meant his theory chiefly as a criticism of socialistic and communistic schemes, which would equalize wealth and do away with competition in society. Unquestionably any such scheme to equalize wealth and do away with competition in society would result in the enormous increase of the lower and more brutal element of society--those that have not yet participated in modern culture. Malthus's theory as a criticism of socialistic schemes that would do away with competition (this, however, does not apply to modern scientific socialism) is unquestionably as good to-day as when it was written. Most modern economists and sociologists recognize the failure of Malthus to formulate a successful theory of population, and so many have attempted to form theories independent of Malthus; but it must be said regarding most of these attempts that they have succeeded no better than Malthus. For example, a French economist and sociologist, Arsène Dumont, has formulated the theory that society is like a sponge so far as population is concerned,--that it will take up just as many new individuals as it has industrial room for, and that population will in all cases expand to meet these increased economic opportunities. Dumont's theory is that population will increase so far as what he calls the power of social capilarity extends. The law of population is, then, the capilarity of society. Where there are new economic opportunities population will increase; where there are no new economic opportunities there will be no increase. France has no new economic opportunities, so the population will not increase. The same is true of certain classes in the United States. This theory tries to make population depend even more entirely upon economic conditions than Malthus's theory. At first it appears more plausible than Malthus's theory, but this is probably because it is more vague. Economic influences are powerful influences, as we have already seen, in determining the growth of a population, but they are not the only ones. The factors which make up the surplus of births over deaths are so complex that they cannot possibly be lumped together and called collectively economic conditions.