"This saying of Huxley's has been repeated so often that one almost wishes it were true; but unfortunately I cannot find a definition of common sense that fits the phrase. Sometimes the word is used as if it were identical with uncommon sense, sometimes as if it were the same thing as common nonsense. Often it means untrained intelligence, and in its best aspect it is, I think, that faculty which recognises that the obvious solution of a problem is frequently the right one. When, for instance, I see during a total solar eclipse red flames shooting out from the edge of the sun, the obvious explanation is that these are real phenomena, caused by masses of glowing vapours ejected from the sun. And when a learned friend tells me that all this is an optical illusion due to anomalous refraction, I object on the ground that the explanation violates my common sense. He replies by giving me the reasons which have led him to his conclusions; and though I still believe that I am right, I have to meet him with a more substantial reply than an appeal to my own convictions. Against a solid argument common sense has no power, and must remain a useful but fallible guide which both leads and misleads all classes of the community alike." The sound moral of this is, not that a common-sense explanation is likely to be the right one, or that it necessarily has any merits if there are sound reasons to oppose to it, but that the common sense or most obvious and superficial explanation _may_ turn out to be after all truer as well as simpler than more recondite hypotheses which have been substituted for it. In other words--the straightforward explanation need not be false. Now the phenomena encountered in psychical research have long ago suggested an explanation, in terms of other than living human intelligences, which may be properly called spiritistic. Every kind of alternative explanation, including the almost equally unorthodox one of telepathy from living people, has been tried: and these attempts have been necessary and perfectly legitimate. If they had succeeded, well and good; but inasmuch as in my judgment there are phenomena which they cannot explain, and inasmuch as some form of spiritistic hypothesis, given certain postulates, explains practically all, I have found myself driven back on what I may call the common-sense explanation; or, to adopt Dr. Schuster's parable, I consider that the red flames round the sun are what they appear to be.