Medium, as an abstraction, is a term loaded with meaning but it has been such a perfect servant in so many fields of endeavour. The figure of the medium has been used in a broad range of epistomological discourses, from science through to literature, but never in exactly the same way.

In Spiritualism, the medium was the conduit by which beings from 'behind the veil' were able to be made present in the world. Mediums, who were very often women, operated in a way not dissimilar to a kind of cosmic telephone or radio. They gained their power by virtue of their effectivity in communicating with the dead and interpreting those communications and conveying them to the living. In this sense, family historians operate as mediums in conveying information about the lives of those who have passed before us, arranging facts into narratives, imposing some order on the historical record.

"May we not regard ether or the medium as not merely a bridge between one portion of the visible universe and another, but also as a bridge between one order of things and another, forming as it were a species of cement, in virtue of which the various orders of the universe are welded together and made into one? In fine, what we generally call ether may not be a mere medium, but a medium plus the invisible order of things." (Steward and Tait, 1875, p.158)