The Charwoman's Shadow by Lord Dunsany

Next morning Ramon Alonzo descended blithely the steps of timber and stone, and soon he was listening to the magician's lecture with his thoughts away in the village of Aragona. The magician explained that there was but one element, of which all material things were composed, but that the fragments of this element that made all matter were variously and diversely knit together. When these elemental fragments were closely associated he explained that their bulk was heavy and often smooth; when more loosely knit, the material they formed was lighter and of a rougher surface. To change therefore the mere arrangement of its fragments was to change one metal to another, at least in the estimation of the vulgar, who knew not that there was but one element and that no true change was possible, all matter being only the varying aspects of an element eternally unchangeable. Even water was made of it and even air.

"Hence," said the Master of the Art, "we see the superiority of spiritual things, which are of a vast multiplicity, while matter is but one. Moreover spirits have much control over matter; while matter has neither the will nor knowledge nor power to affect one spirit, even though it may chance, upon a journey, to come close to a whole world. " And the magician continued his theme, so that never was the cause of the spirit so ably pleaded, nor matter more humbled, nor all its pretensions more completely exposed. But Ramon Alonzo's daydreams were in arbours of Aragona, and they did not return thence until the magician, looking out carefully at the height of the sun, said: "Now you may go down to the haunts of error until the sun is westering. And now this lesson concludes. Be sure that you have learned a greater wisdom in learning the oneness of matter than is to be found in the changing of its manifestation out of its leaden form to that form which is held in greater esteem by the vulgar."