Yet the history of thought should warn us against concluding that because the scientific theory of the world is the best that has yet been formulated, it is necessarily complete and final. We must remember that at bottom the generalisations of science or, in common parlance, the laws of nature are merely hypotheses devised to explain that ever-shifting phantasmagoria of thought which we dignify with the high-sounding names of the world and the universe. In the last analysis magic, religion, and science are nothing but theories of thought; and as science has supplanted its predecessors, so it may hereafter be itself superseded by some more perfect hypothesis, perhaps by some totally different way of looking at the phenomenaof registering the shadows on the screenof which we in this generation can form no idea. The advance of knowledge is an infinite progression towards a goal that for ever recedes. We need not murmur at the endless pursuit:
Fatti non foste a viver come bruti Ma per seguir virtute e conoscenza.
Great things will come of that pursuit, though we may not enjoy them.
Brighter stars will rise on some voyager of the futuresome great Ulysses of the realms of thoughtthan shine on us. The dreams of magic may one day be the waking realities of science. But a dark shadow lies athwart the far end of this fair prospect. For however vast the increase of knowledge and of power which the future may have in store for man, he can scarcely hope to stay the sweep of those great forces which seem to be making silently but relentlessly for the destruction of all this starry universe in which our earth swims as a speck or mote. In the ages to come man may be able to predict, perhaps even to control, the wayward courses of the winds and clouds, but hardly will his puny hands have strength to speed afresh our slackening planet in its orbit or rekindle the dying fire of the sun. Yet the philosopher who trembles at the idea of such distant catastrophes may console himself by reflecting that these gloomy apprehensions, like the earth and the sun themselves, are only parts of that unsubstantial world which thought has conjured up out of the void, and that the phantoms which the subtle enchantress has evoked to-day she may ban to-morrow. They too, like so much that to common eyes seems solid, may melt into air, into thin air.
Without dipping so far into the future, we may illustrate the course which thought has hitherto run by likening it to a web woven of three different threadsthe black thread of magic, the red thread of religion, and the white thread of science, if under science we may include those simple truths, drawn from observation of nature, of which men in all ages have possessed a store.
Could we then survey the web of thought from the beginning, we should probably perceive it to be at first a chequer of black and white, a patchwork of true and false notions, hardly tinged as yet by the red thread of religion. But carry your eye farther along the fabric and you will remark that, while the black and white chequer still runs through it, there rests on the middle portion of the web, where religion has entered most deeply into its texture, a dark crimson stain, which shades off insensibly into a lighter tint as the white thread of science is woven more and more into the tissue. To a web thus chequered and stained, thus shot with threads of diverse hues, but gradually changing colour the farther it is unrolled, the state of modern thought, with all its divergent aims and conflicting tendencies, may be compared. Will the great movement which for centuries has been slowly altering the complexion of thought be continued in the near future? or will a reaction set in which may arrest progress and even undo much that has been done? To keep up our parable, what will be the colour of the web which the Fates are now weaving on the humming loom of time? will it be white or red? We cannot tell. A faint glimmering light illumines the backward portion of the web. Clouds and thick darkness hide the other end.
Our long voyage of discovery is over and our bark has drooped her weary sails in port at last. Once more we take the road to Nemi. It is evening, and as we climb the long slope of the Appian Way up to the Alban Hills, we look back and see the sky aflame with sunset, its golden glory resting like the aureole of a dying saint over Rome and touching with a crest of fire the dome of St. Peter's. The sight once seen can never be forgotten, but we turn from it and pursue our way darkling along the mountain side, till we come to Nemi and look down on the lake in its deep hollow, now fast disappearing in the evening shadows. The place has changed but little since Diana received the homage of her worshippers in the sacred grove. The temple of the sylvan goddess, indeed, has vanished and the King of the Wood no longer stands sentinel over the Golden Bough. But Nemi's woods are still green, and as the sunset fades above them in the west, there comes to us, borne on the swell of the wind, the sound of the church bells of Aricia ringing the Angelus.
Ave Maria! Sweet and solemn they chime out from the distant town and die lingeringly away across the wide Campagnan marshes. Le roi est mort, vive le roi! Ave Maria!