A number of facts regarding the phenomena of light were observed and classified and it was found that these could be explained by the hypothesis that light consisted of a stream of very minute particles moving at very high speed which impinged upon the eye and thus gave rise to the sensations observed. Up to a point this explanation was perfectly satisfactory and for a long time it held the field, partly because of the great prestige of Newton to whom much of its development was due and partly because it continued to explain subsequently observed facts without much straining.
But among other things it was demonstrated that in order to account for the observed phenomena of refraction it was necessary to suppose that the "Corpuscles" travelled faster in water than in air.
At first there was no means of determining directly whether this was so or not. But later the researches of Foucault made it possible to settle the point by direct measurement. When the velocity of light in air and water respectively was measured directly by Foucault's method it was found that the velocity in water was less than that in air. The Corpuscular theory was therefore untenable.
It is only by this process of forming, testing and, if necessary, rejecting hypotheses that we gradually attain to exact knowledge. As Prof. Richet says:
"La science n'a jamais été qu'une serie d'erreurs, approximations constamment evoluant constamment boulversé, et cela d'autant plus vite qu'elle était plus avancée."
(Annales des sciences psychiques, 1905, p. 15.)
From this brief resumé of the steps involved in scientific progress it is clear that the formation of a working hypothesis, by inductive reasoning from the observed facts, is a normal, necessary, and invariable step in the progress of any science whatsoever.
For this reason I do not think it likely that Psychical research will attain any widespread recognition as a science until it is in possession of a valid working hypothesis capable of explaining at least the more important of the observed facts. I believe that the higher space hypothesis fulfills this condition and if so it is clearly worth while adopting, purely provisionally and tentatively of course, by those who concern themselves with the subject.
I have said that I think that the conception of higher space has a bearing on the relations between Religious and Scientific thought.