"He had found in every country in the world traditions of a race who were human--yet more than human. That is the most exact fashion in which I can express his beginnings. On every side he found the notion of a race who can impinge on mortal life and partake of it--but always without exercising the last reach of their endowments. Oh, the tradition exists everywhere, whether you call these occasional interlopers fauns, fairies, gnomes, ondines, incubi, or demons. They could, according to these fables, temporarily restrict themselves into our life, just as a swimmer may elect to use only one arm--or, a more fitting comparison, become apparent to our human senses in the fashion of a cube which can obtrude only one of its six surfaces into a plane. You follow me, of course, sir?--to the triangles and circles and hexagons this cube would seem to be an ordinary square. Conceiving such a race to exist, we might talk with them, might jostle them in the streets, might even intermarry with them, sir--and always see in them only human beings, and solely because of our senses' limitations." "I comprehend. These are exactly the speculations that would appeal to an unbalanced mind--is that not your thought, Philip?" "Why, there is nothing particularly insane, Sir Thomas, in desiring to explore in fields beyond those which our senses make perceptible. It is very certain these fields exist; and the question of their extent I take to be both interesting and important." Then Sir Thomas said: "Like any other rational man, I have occasionally thought of this endeavor at which you hint. We exist--you and I and all the others--in what we glibly call the universe. All that we know of it is through what we entitle our five senses, which, when provoked to action, will cause a chemical change in a few ounces of spongy matter packed in our skulls. There are no grounds for believing that this particular method of communication is adequate, or even that the agents which produce it are veracious. Meanwhile, we are in touch with what exists through our five senses only. It may be that they lie to us. There is, at least, no reason for assuming them to be infallible."