A supposed physical force emanating from the person of the medium and directed by his or her will, by means of which objects may be moved without contact in apparent defiance of natural laws. The existence of such a psychic force was postulated by Count Agenor de Gasparin in the mid-nineteenth century to explain the phenomena of table-turning and rapping, and the term ectenic force was bestowed upon the supposed agency by de Gasparin's colleague Marc Thury.
The experiments of Thury and de Gasparin were widely cited as among the most convincing evidence that Spiritualism could produce, and influenced many eminent students of psychic research. If tables can be moved without contact, then such a theory is plausible, but the evidence for this type of phenomena is not abundant. During the latter twentieth century, the phenomenon postulated by Thury and de Gasparin has been placed under the broad label of psychokinesis.