And below—What could be more clear, more certain, than this—that as above the earth was the kingdom of light, and joy, and holiness, so below the earth was the kingdom of darkness, and torment, and sin? What could be more certain? Had not even the heathens said so, by the mouth of the poet Virgil? What could be more simple, rational, orthodox, than to adopt (as they actually did) Virgil’s own words, and talk of Tartarus, Styx, and Phlegethon, as indisputable Christian entities. They were not aware that the Buddhists of the far East had held much the same theory of endless retribution several centuries before; and that Dante, with his various _bolge_, tenanted each by its various species of sinners, was merely re-echoing the horrors which are to be seen painted on the walls of any Buddhist temple, as they were on the walls of so many European churches during the Middle Ages, when men really believed in that same Tartarology, with the same intensity with which they now believe in the conclusions of astronomy or of chemistry. To them, indeed, it was all an indisputable or physical fact, as any astronomic or chemical fact would have been; for they saw it with their own eyes. Virgil had said that the mouth of Tartarus was there in Italy, by the volcanic lake of Avernus; and after the first eruption of Vesuvius in the first century, nothing seemed more probable. Etna, Stromboli, Hecla, must be, likewise, all mouths of hell; and there were not wanting holy hermits who had heard within those craters, shrieks and clanking chains, and the shouts of demons tormenting endlessly the souls of the lost. And now, how has all this been shaken? How much of all this does any educated man, though he be pious, though he desire with all his heart to be orthodox—and is orthodox in fact—how much of all this does he believe, as he believes that the earth is round, or, that if he steals his neighbour’s goods he commits a crime? For, since these days, the earth has been shaken, and with it the heavens likewise, in that very sense in which the expression is used in the text. Our conceptions of them have been shaken. The Copernican system shook them, when it told men that the earth was but a tiny globular planet revolving round the sun. Geology shook them, when it told men that the earth has endured for countless ages, during which whole continents have been submerged, whole seas become dry land, again and again. Even now the heavens and the earth are being shaken by researches into the antiquity of the human race, and into the origin and the mutability of species, which, issue in what results they may, will shake for us, meanwhile, theories which are venerable with the authority of nearly eighteen hundred years, and of almost every great Doctor since St. Augustine.