Hyslop, J. H. (1906). Clairvoyance. In J. H. Hyslop, Enigmas of psychical research (pp. 272-305). Boston, MA, US: Herbert B Turner & Co.
http://dx.doi.org/10.1037/13666-008
Clairvoyance technically, therefore, is a name for a supposed or alleged process of perceiving objects or scenes at a distance and without any of the normal impressions of sense. represents perception of distant objects rather than the perception of distant minds. That is, at least, the superficial appearance of the phenomena. It is, therefore, narrowed down to a process apparently analogous to vision, with the difference that it is supernormal, whereas ordinary vision is normal. Whether the alleged phenomenon is possible or not I shall not assume at present. I shall only recount first the alleged facts presumed to suggest or support the claim. In presenting the facts claiming classification as clairvoyant I shall have no reference to their ultimate explanation. It may be that they will articulate either with telepathy or hyperesthesia at various times, but it will appear difficult in others to suppose any such complication. (PsycINFO Database Record (c) 2016 APA, all rights reserved)