Perfectibility, as expounded by Condorcet and Godwin, encountered a drastic criticism from Malthus, whose Essay on the Principle of Population appeared in its first form anonymously in 1798.  Condorcet had foreseen an objection which might be raised as fatal to the realisation of his future state.  Will not the progress of industry and happiness 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 society could be modified by the conscious efforts of man only within restricted limits. [Footnote:  The recent conclusions of Mr. Knibbs, statistician to the Commonwealth of Australia, in vol. i. of his