I do not want to defend the occult sciences; I am, however, convinced that further unbiased investigation of these phenomena by collection and evaluation of old and new evidence, in the usual scientific manner, will lead us sooner or later to the discovery of new and important relations of which we have as yet no knowledge, but which are natural phenomena in the usual sense.

Third Lecture, Critical Discussion of the Foundations of Probability, p. 74 - Probability, Statistics And Truth - Second Revised English Edition - (1957)