There is one special piece of ancient metaphysics which until recently scientific and religious sects have alike combined to support: the fiction of “matter,” which we passingly came upon when considering the art of thinking. It is a fiction that has much to answer for in distorting the scientific spirit and in creating an artificial opposition between science and religion. All sorts of antique metaphysical peculiarities, inherited from the decadence of Greek philosophy, were attributed to “matter” and they were mostly of a bad character; all the good qualities were attributed to “spirit”; “matter” played the Devil’s part to this more divine “spirit.” Thus it was that “materialistic” came to be a term signifying all that is most heavy, opaque, depressing, soul-destroying, and diabolical in the universe. The party of traditionalised religion fostered this fiction and the party of traditionalised science frequently adopted it, cheerily proposing to find infinite potentialities in this despised metaphysical substance. So that “matter” which was on one side trodden underfoot was on the other side brandished overhead as a glorious banner. Yet “matter,” as psychologically minded philosophers at last began to point out, is merely a substance we have ourselves invented to account for our sensations. We see, we touch, we hear, we smell, and by a brilliant synthetic effort of imagination we put together all those sensations and picture to ourselves “matter” as being the source of them. Science itself is now purging “matter” of its complicated metaphysical properties. That “matter,” the nature of which Dr. Johnson, as Boswell tells us, thought he had settled by “striking his foot with mighty force against a large stone,” is coming to be regarded as merely an electrical emanation. We now accept even that transmutation of the elements of which the alchemists dreamed. It is true that we still think of “matter” as having weight. But so cautious a physicist as Sir Joseph Thomson long ago pointed out that weight is only an “apparently” invariable property of matter. So that “matter” becomes almost as “ethereal” as “spirit,” and, indeed, scarcely distinguishable from “spirit.” The spontaneous affirmation of the mystic that he lives in the spiritual world here and now will then be, in other words, merely the same affirmation which the man of science has more laboriously reached. The man, therefore, who is terrified by “materialism” has reached the final outpost of absurdity. He is a simple-minded person who places his own hand before his eyes and cries out in horror: The Universe has disappeared!