New writers now appear who add gradually stone after stone to the good foundation already laid, and raise the edifice to fairer proportions. The first considerable addition comes from a contribution by a country clergyman, Thomas Robert Malthus,(30) in his “Essay on the Principles of Population” (1798). Against the view of Pitt that “the man who had a large family was a benefactor to his country,” Malthus argued conclusively that “a perfectly happy and virtuous community, by physical law, is constrained to increase very rapidly.... By nature human food increases in a slow arithmetical ratio; man himself increases in a quick geometrical ratio, unless want and vice stop him.” In his second edition (1803), besides the positive check of vice and want, he gave more importance to the negative check of “self-restraint, moral and prudential.” The whole theory was crudely stated at first; and it raised the cry that such a doctrine was inconsistent with the belief in a benevolent Creator. In its essence, the law of population is simply that a tendency and ability exist in mankind to increase its numbers faster than subsistence, and that this result actually will happen unless checks retard it, or new means of getting subsistence arise. If an undue increase of population led to vice and misery, in Malthus’s theory, he certainly is not to be charged with unchristian feelings if he urged a self-restraint by which that evil result should be avoided. Malthus’s doctrines excited great discussion: Godwin says that by 1820 thirty or forty answers to the essay had been written; and they have continued to appear. The chief contributions have been by A. H. Everett, “New Ideas on Population” (1823), who believed that an increase of numbers increased productive power; by M. T. Sadler, “Law of Population” (1830), who taught that human fertility varied inversely with numbers, falling off with density of population; by Sir Archibald Alison, “Principles of Population” (1840), who reasoned inductively that the material improvement of the human race is a proof that man can produce more than he consumes, or that in the progress of society preventive checks necessarily arise; by W. R. Greg, “Enigmas of Life” (1873); and by Herbert Spencer, “Westminster Review” (April, 1852), and “Principles of Biology,” (part vi, ch. xii and xiii), who worked out a physiological check, in that with a mental development out of lower stages there comes an increased demand upon the nervous energy which causes a diminution of fertility. Since Darwin’s studies it has been very generally admitted that it is the innate _tendency_ of all organic life to increase until numbers press upon the limit of food-production; not that population has always done so in every country.(31) Malthus’s teachings resulted in the modern poor-house system, beginning with 1834 in England, and they corrected some of the abuses of indiscriminate charity.