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. Dumont's theory of
the growth of population has no more scientific value than Malthus's
theory.

In conclusion, we may say that we are unable to formulate any laws of
population which are worthy of the name of laws as yet, and it seems
probable that, while we may understand clearly enough the factors which