The neglect of industry and the depreciation of secular pursuits proved the death-blow of rational agriculture. The garden-lands of the Old World became sand-wastes, the soil of the neglected fields was scorched by summer suns and torn by winter floods till three million square miles of once fruitful lands were turned into hopeless deserts. “The fairest and fruitfulest provinces of the Roman empire,” says Professor Marsh—“precisely that portion of terrestrial surface, in short, which about the commencement of the Christian era was endowed with the greatest superiority of soil, climate, and position, which had been carried to the highest pitch of physical improvement—is now completely exhausted of its fertility. A territory larger than all Europe, the abundance of which sustained in bygone centuries a population scarcely inferior to that of the whole Christian world at the present day, has been entirely withdrawn from human use, or, at best, is thinly inhabited.... There are regions, where the operation of causes, set in action by man, has brought the face of the earth to a state of desolation almost as complete as that of the moon; and though within that brief space of time which we call the historical period, they are known to have been covered with luxuriant woods, verdant pastures, and fertile meadows, they are now too far deteriorated to be reclaimable by man, nor can they become again fitted for his use except through great geological changes or other agencies, over which we have no control.... Another era of equal improvidence would reduce this earth to such a condition of impoverished productiveness as to threaten the depravation, barbarism, and, perhaps, even the extinction of the human species” (Man and Nature, pp. 4, 43). The experience of the Middle Ages has, indeed, been bought at a price which the world cannot afford to pay a second time. The sacrifices of fifteen centuries have failed to purchase the millennium of the Galilean Messiah, and the time has come to seek salvation by a different road. The Religion of the Future will preach the Gospel of Redemption by reason, by science, and by conformity to the laws of our health-protecting instincts. Its teachings will reconcile instinct and precept, and make Nature the ally of education. Its mission will seek to achieve its triumphs, not by the suppression, but by the encouragement of free inquiry; it will dispense with the aid of pious frauds; its success will be a victory of truth, of freedom, and humanity; it will reconquer our earthly paradise, and teach us to renounce the Eden that has to be reached through the gates of death. I.—PHYSICAL MAXIMS. CHAPTER I. HEALTH. A.—LESSONS OF INSTINCT.