The greatest contribution of psychical research to philosophy (or should I say "supersession of philosophy by psychical research"?), if the conclusions of some psychical researchers are true, is to another of those great questions traditionally included under the word "philosophy", from which Mrs. Kneale cut herself off by a self-denying ordinance. I refer to the choice between what may be roughly called the Platonic and the Aristotelian theories of man. According to the Platonic theory, a man is primarily something immortal and imperceptible and spiritual, which for one or more short periods is united with something mortal and perceptible and material, namely a specimen of that animal labelled "homo sapiens" by the biologists. According to the Aristotelian theory, man is that animal labelled "homo sapiens" by the biologists; and that animal is not linked to any immortal imperceptible twin (you see I am disregarding the famous little chapter in which Aristotle reverts to Platonism); and what we refer to as its "soul" or "mind" is the entelechy or form or higher behaviour of that animal.
In my opinion the main object of many psychical researchers is to establish the Platonic view of man on the best scientific and legal evidence, and to remove the immense support which science gave to the Aristotelian view of man in the nineteenth century. The central part of their psychical research is therefore the attempt to communicate with men who are not at the time attached to any specimen of homo sapiens; and all the matters dealt with by Mrs. Kneale, the mental as well as the physical, are to them merely outliers whose main value is that they suggest the occurrence of activity with no physical basis. Consequently, the main relevance of their psychical research to philosophy is that, if you accept their conclusions, you ought in consistency to deny all Aristotelian theories of man, and, if you accept an Aristotelian theory of man, you ought to deny their conclusions.
I personally accept an Aristotelian theory of man, and deny at least their main conclusion. I find this a painful position, as the most eminent persons who have published on the subject appear to be on the other side. I have, however, no choice in the matter. I cannot help believing the Aristotelian view and disbelieving the Platonic view.
(Richard Robinson, "Is Psychical Research Relevant to Philosophy?" The Aristotelian Society, supplementary volume 24 [1950]: 189-206, at 202-3 [italics in original])
Keith Burgess-Jackson, J.D., Ph.D. 