Michael Foster said in his Presidential Address to the British Association at Dover:—
"Men of science have no peculiar virtues, no special powers. They are ordinary men, their characters are common, even commonplace. Science, as Huxley said, is organised common sense, and men of science are common men, drilled in the ways of common sense."
This of course, like any aphorism, does not bear pressing unduly: and Dr. Arthur Schuster in a similar Address at Manchester hedged it round with qualifying clauses:—
"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.
To attribute capricious mechanical performance to the action of live things, is sufficient as a proximate explanation; as we saw in the case of the jumping bean, Chapter I. If the existence of the live thing is otherwise unknown, the explanation may seem forced and unsatisfactory. But if after trying other hypotheses we find that this only will fit the case, we may return to it after all with a clear conscience. That represents the history of my own progress in Psychical Research.
Apologia
Meanwhile the attitude of scientific men is perfectly intelligible; and not unreasonable, except when they forget their self-imposed limitations and cultivate a baseless negative philosophy. People who study mechanism of course find Mechanics, and if the mechanism is physiological they find Physics and Chemistry as well; but they are not thereby compelled to deny the existence of everything else. They need not philosophise at all, though they should be able to realise their philosophical position when it is pointed out. The business of science is to trace out the mode of action of the laws of Chemistry and Physics, everywhere and under all circumstances. Those laws appear to be of universal application throughout the material Universe,—in the most distant star as well as on the earth,—in the animal organism as well as in inorganic matter; and the study of their action alone has proved an ample task.
But scientific workers are sometimes thought to be philosophising seriously when they should be understood as really only expressing the natural scope of their special subject. Laplace, for instance, is often misunderstood, because, when challenged about the place of God in his system, he said that he had no need of such a hypothesis,—a dictum often quoted as if it were atheistical. It is not necessarily anything of the kind. As a brief statement it is right, though rather unconciliatory and blunt. He was trying to explain astronomy on clear and definite mechanical principles, and the introduction of a "finger of God" would have been not only an unwarrantable complication but a senseless intrusion. Not an intrusion or a complication in the Universe, be it understood, but in Laplace's scheme, his Systéme du Monde. Yet Browning's "flash of the will that can" in Abt Vogler, with all that the context implies, remains essentially and permanently true.