Dowsing
Dowsing (or radiesthesia) is a practice of detection with the help of an oscillating instrument (pendulum, dowsing rod, Y-shaped fork) supposed to react to sought information: underground water, lost object, state of health, answer to a question.
Origin and etymology
The French word radiesthesie was coined in 1930 by Abbe Alex Bouly from the Latin radius (ray) and the Greek aisthesis (perception). The practice itself is much older. Rhabdomancy (from the Greek rhabdos, rod) is attested in Herodotus in the 5th century BCE among the Scythians. Water dowsing, the search for water with a rod, is documented in Western Europe as early as the 15th century, notably in the German mines of the Harz described by Georgius Agricola in De Re Metallica (1556). The pendulum as an instrument developed in the 19th century, popularized by Abbe Mermet (1866-1937), a Swiss priest and dowser who codified a systematic method in Principles and Practice of Radiesthesia (1934).
Evolution and tradition
Modern dowsing diversified in the 20th century. Medical dowsing, practiced notably by Abbe Mermet, claims to detect organic dysfunctions. Mental dowsing or teleradiesthesia, developed by Mermet and then by Antoine de Belizal, extends the practice to remote targets through mental projection. Standardized dowsing charts allow the pendulum to designate an answer among prepared options. Controlled scientific tests conducted since the 1940s, notably the German study by Hans-Dieter Betz in Munich in 1989, have not confirmed any detection ability beyond chance.
Practical use
Common practice uses a pendulum (crystal, metal or wood) held above a chart, a map or an object. The pendulum oscillates in response to involuntary micromovements of the hand (ideomotor effect), interpreted as a symbolic answer. On Tarotoui, dowsing is documented among the divinatory practices. A typical session begins with calibrating the pendulum (establishing the yes / no oscillations), and then formulating a clear question. The practice suits binary questions or choices among a small number of options. It is also used to look for water or objects.
Going further
Controlled studies attribute dowsing results to the ideomotor effect: involuntary micromovements reflecting the operator's unconscious expectations. Dowsing therefore remains a tool for dialogue with one's intuition rather than an objective extrasensory perception. Note also that medical dowsing is forbidden in France for diagnosis, regarded as the illegal practice of medicine.