No less than a planet will serve the purpose of a modern Utopia. Time was when a mountain valley or an island seemed to promise sufficient isolation for a polity to maintain itself intact from outward force; the Republic of Plato stood armed ready for defensive war, and the New Atlantis and the Utopia of More in theory, like China and Japan through many centuries of effectual practice, held themselves isolated from intruders. Such late instances as Butler's satirical "Erewhon," and Mr. Stead's queendom of inverted sexual conditions in Central Africa, found the Tibetan method of slaughtering the inquiring visitor a simple, sufficient rule. But the whole trend of modern thought is against the permanence of any such enclosures. We are acutely aware nowadays that, however subtly contrived a State may be, outside your boundary lines the epidemic, the breeding barbarian or the economic power, will gather its strength to overcome you. The swift march of invention is all for the invader. Now, perhaps you might still guard a rocky coast or a narrow pass; but what of that near to-morrow when the flying machine soars overhead, free to descend at this point or that? A state powerful enough to keep isolated under modern conditions would be powerful enough to rule the world, would be, indeed, if not actively ruling, yet passively acquiescent in all other human organisations, and so responsible for them altogether. World-state, therefore, it must be. That leaves no room for a modern Utopia in Central Africa, or in South America, or round about the pole, those last refuges of ideality. The floating isle of La Cite Morellyste no longer avails. We need a planet. Lord Erskine, the author of a Utopia ("Armata") that might have been inspired by Mr. Hewins, was the first of all Utopists to perceive this--he joined his twin planets pole to pole by a sort of umbilical cord. But the modern imagination, obsessed by physics, must travel further than that. Out beyond Sirius, far in the deeps of space, beyond the flight of a cannon-ball flying for a billion years, beyond the range of unaided vision, blazes the star that is _our_ Utopia's sun. To those who know where to look, with a good opera-glass aiding good eyes, it and three fellows that seem in a cluster with it--though they are incredible billions of miles nearer--make just the faintest speck of light. About it go planets, even as our planets, but weaving a different fate, and in its place among them is Utopia, with its sister mate, the Moon. It is a planet like our planet, the same continents, the same islands, the same oceans and seas, another Fuji-Yama is beautiful there dominating another Yokohama--and another Matterhorn overlooks the icy disorder of another Theodule. It is so like our planet that a terrestrial botanist might find his every species there, even to the meanest pondweed or the remotest Alpine blossom....