THREE:On passing to terrestrial physics, we find that Aristotle is, as usual, the dupe of superficial appearances, against which other thinkers were on their guard. Seeing that fire always moved up, he assumed that it did so by virtue of a natural tendency towards the circumference of the universe, as opposed to earth, which always moved towards the centre. The atomists erroneously held that all matter gravitated downwards through infinite space, but correctly explained the ascent of heated particles by the pressure of surrounding matter, in accordance, most probably, with the analogy of floating bodies.200 Chemistry as a science is, of course, an entirely modern creation, but the first approach to it was made by Democritus, while no ancient philosopher stood farther from its essential principles than Aristotle. He analyses bodies, not into their material elements, but into the sensuous qualities, hot and cold, wet and dry, between which he supposes the underlying substance to be perpetually oscillating; a theory which, if it were true, would make any fixed laws of nature impossible.So far, we have only considered belief in its relation to the re-distribution of political, social, and national forces. But behind all such forces there is a deeper and more perennial cause of intellectual revolution at work. There is now in the world an organised and ever-growing mass of scientific truths, at least a thousand times greater and a thousand times more diffused than the amount of positive knowledge possessed by mankind in the age of the Antonines. What those truths can do in the future may be inferred from what they have already done in the past. Even the elementary science of Alexandria, though it could not cope with the supernaturalist reaction of the empire, proved strong enough, some centuries later, to check the flood of Mahometan fanaticism, and for a time to lead captivity captive in the very strongholds of militant theological belief. When, long afterwards, Jesuitism and Puritanism between them threatened to reconquer all that the humanism of the Renaissance had won from superstition, when all Europe from end to end was red with the blood or blackened with the death-fires of heretics and witches, science, which had meanwhile been silently laying the foundations of265 a new kingdom, had but to appear before the eyes of men, and they left the powers of darkness to follow where she led. When the follies and excesses of the Revolution provoked another intellectual reaction, her authority reduced it to a mere mimicry and shadow of the terrible revenges by which analogous epochs in the past history of opinion had been signalised. And this was at a time when the materials of reaction existed in abundance, because the rationalistic movement of the eighteenth century had left the middle and lower classes untouched. At the present moment, Catholicism has no allies but a dispirited, half-sceptical aristocracy; and any appeal to other quarters would show that her former reserves have irrevocably passed over to the foe. What is more, she has unconsciously been playing the game of rationalism for fifteen centuries. By waging a merciless warfare on every other form of superstition, she has done her best to dry up the sources of religious belief. Those whom she calls heathens and pagans lived in an atmosphere of supernaturalism which rendered them far less apt pupils of philosophy than her own children are to-day. It was harder to renounce what she took away than it will be to renounce what she has left, when the truths of science are seen by all, as they are now seen by a few, to involve the admission that there is no object for our devotion but the welfare of sentient beings like ourselves; that there are no changes in Nature for which natural forces will not account; and that the unity of all existence has, for us, no individualisation beyond the finite and perishable consciousness of man.
