A word or two more may be said about the City of the Sun. Campanella was as earnest a believer in the interrogation of nature as Bacon, and the place which science and learning hold in his state (although research is not so prominent as in the New Atlantis), and the scientific training of all the citizens, are a capital feature. The progress in inventions, to which science may look forward, is suggested. The men of the City of the Sun "have already discovered the one art which the world seemed to lack--the art of flying; and they expect soon to invent ocular instruments which will enable them to see the invisible stars and auricular instruments for hearing the harmony of the spheres." Campanella's view of the present conditions and prospects of knowledge is hardly less sanguine than that of Bacon, and characteristically he confirms his optimism by astrological data. "If you only knew what their astrologers say about the coming age. Our times, they assert, have more history in a hundred years than the whole world in four thousand. More books have been published in this century than in five thousand years before. They dwell on the wonderful inventions of printing, of artillery, and of the use of the magnet,--clear signs of the times--and also instruments for the assembling of the inhabitants of the world into one fold," and show that these discoveries were conditioned by stellar influences. But Campanella is not very sure or clear about the future. Astrology and theology cause him to hesitate. Like Bacon, he dreams of a great Renovation and sees that the conditions are propitious, but his faith is not secure. The astronomers of his imaginary state scrutinise the stars to discover whether the world will perish or not, and they believe in the oracular saying of Jesus that the end will come like a thief in the night. Therefore they expect a new age, and perhaps also the end of the world. The new age of knowledge was about to begin. Campanella, Bruno, and Bacon stand, as it were, on the brink of the dividing stream, tenduntque manus ripae ulterioris amore. CHAPTER III. CARTESIANISM If we are to draw any useful lines of demarcation in the continuous flux of history we must neglect anticipations and announcements, and we need not scruple to say that, in the realm of knowledge and thought, modern history begins in the seventeenth century. Ubiquitous rebellion against tradition, a new standard of clear and precise thought which affects even literary expression, a flow of mathematical and physical discoveries so rapid that ten years added more to the sum of knowledge than all that had been added since the days of Archimedes, the introduction of organised co-operation to increase knowledge by the institution of the Royal Society at London, the Academy of Sciences at Paris, Observatories--realising Bacon's Atlantic dream--characterise the opening of a new era.