THREE:What seems to us the reactionary attitude of the spiritu357alist school was dictated by the circumstances of its origin. A product of the great classical revival, its cause was necessarily linked with the civilisation of ancient Greece, and of that civilisation the worship of the old gods seemed to form an integral element. One need only think of the Italian Renaissance, with its predilection for the old mythology, to understand how much stronger and more passionate this feeling must have been among those to whom Greek literature still spoke in a living language, whose eyes, wherever they turned, still rested on the monuments, unrivalled, undesecrated, unfallen, unfaded, of Greek religious art. Nor was polytheism what some have imagined it to have been at this period, merely a tradition, an association, a dream, drawing shadowy sustenance from the human works and human thoughts which it had once inspired. To Plotinus and Proclus, as formerly to Socrates and Plato and Aristotle, the luminaries of day and night blazed down from heaven as animated and immortal witnesses of its truth. It was not simply that the heavens declared the glory of God; to the pious beholder, they were visibly inhabited by glorious gods, and their constellated fires were, as Plotinus said, a scripture in which the secrets of destiny might be read. The same philosopher scornfully asks the Gnostics, who, in this respect, were indistinguishable from the Christians, whether they were so infatuated as to call the worst men their brothers, while refusing that title to the sun; and at a much later period, notwithstanding the heavy penalties attached to it, the worship of the heavenly bodies continued to be practised by the profoundest thinkers and scholars of the Neo-Platonic school.529 Moreover, polytheism, by the very weakness and unfixity of its dogmas, gave a much wider scope to independent speculation than could be permitted within the limits of the358 Catholic Church, just because Catholicism itself constituted a philosophical system in which all the great problems of existence were provided with definite and authoritative solutions.Chemistry also received valuable extensions of its field. Dr. John Mayow published new facts respecting nitre, and on the phenomena of respiration and combustion, as revealed by experiments on this and other substances. At the commencement of the eighteenth century Stahl, a German chemist, propounded his theory of phlogiston as the principle of combustion, which was only exploded by the further discoveries of Dr. Black, Cavendish, and Priestley. Soon after, Dr. Hales threw new light on a?riform bodies, or, as they are now termed, gases; and finally, Dr. Black demonstrated the presence of a gas in magnesia, lime, and the alkalies, which had long before been noticed by Van Helmont, but had been forgotten. This was then termed fixed air, but has now acquired the name of carbonic acid gas, or carbon dioxide. At the end of this period chemistry was extensively studied, and was rapidly revealing its secrets.
