cause a steady increase in population, and must not the time come when
the number of the inhabitants of the globe will surpass their means of
subsistence? Condorcet did not grapple with this question. He contented
himself with saying that such a period must be very far away, and that
by then "the human race will have achieved improvements of which we can
now scarcely form an idea." Similarly Godwin, in his fancy picture of
the future happiness of mankind, notices the difficulty and shirks it.
"Three-fourths of the habitable globe are now uncultivated. The parts
already cultivated are capable of immeasurable improvement. Myriads of
centuries of still increasing population may pass away and the earth be
still found sufficient for the subsistence of its inhabitants."

Malthus argued that these writers laboured under an illusion as to the
actual relations between population and the means of subsistence. In
present conditions the numbers of the race are only kept from increasing
far beyond the means of subsistence by vice, misery, and the fear of
misery. [Footnote: This observation had been made (as Hazlitt pointed
out) before Malthus by Robert Wallace (see A Dissertation on the Numbers
of Mankind, p. 13, 1753). It was another book of Wallace that suggested
the difficulty to Godwin.] In the conditions imagined by Condorcet and
Godwin these checks are removed, and consequently the population would
increase with great rapidity, doubling itself at least in twenty-five
years. But the products of the earth increase only in an arithmetical
progression, and in fifty years the food supply would be too small for
the demand. Thus the oscillation between numbers and food supply would
recur, and the happiness of the species would come to an end.

Godwin and his adherents could reply that one of the checks on
over-population is prudential restraint, which Malthus himself
recognised, and that this would come more extensively into operation
with that progress of enlightenment which their theory assumed.
[Footnote: This is urged by Hazlitt in his criticism of Malthus in the
Spirit of the Age.] But the criticisms of Malthus dealt a trenchant
blow to the doctrine that human reason, acting through legislation and
government, has a virtually indefinite power of modifying the condition
of society. The difficulty, which he stated so vividly and definitely,
was well calculated to discredit the doctrine, and to suggest that the
development of soci