RADIESTHESIA. - A term denoting a particular group of phenomena of direct clairvoyance (v.) in which knowledge of the event or entity sought is obtained through a direct relationship established between this and the perceiving subject, using special detecting instruments: the rod or divining fork and the pendulum.
The term, used under the presumption that the phenomena are attributable to hypothetical radiations or wave movements emitted indiscriminately by every body, might also apply to any phenomenon of clairvoyance; in practice, however, the term is used restrictively to indicate the aforementioned form of revelation of facts or things with the rod (rabdomancy: *ràβδος* = rod, *μαντεία* = divination) or with the pendulum.
The object of the research in rabdomantic or pendular activity (the use of the pendulum for radiesthetic research is replacing that of the rod, due to its greater convenience, variety, and accuracy of indications) is highly varied and is represented by any hidden entity belonging to any realm of nature, including qualities, quantities, or locations, even with regard to man, for whom it is also applied as a means of diagnosing the site and nature of ailments, a method for determining the most suitable remedies, and even for investigating internal psychological conditions and biological and social circumstances (feelings, relationships of kinship, responsibility, etc.).
The subject of radiesthesia may be more or less any human being; various authors admit that beings of a lower degree, animals or plants, are capable of regulating their behavior in relation to the radiesthetic faculties with which they are endowed.
For a detailed study of the method of radiesthetic research, reference should be made to specialized works, which should be approached with a critical spirit, as they are largely filled with empirical precepts, rules, and conclusions not supported by rigorous scientific method, insufficiently documented facts, or ambiguous interpretations. The instruments commonly used are the rod or wand; twigs of hazel, elm, or bamboo (excluding resinous woods or olive), whalebone, straight or Y- or V-shaped, obtained by joining two elements with a vegetable ligature; or the pendulum, a small weight (30 to 70 grams) of various materials (wood, bone, plastic substances, metal, possibly even a watch, etc.), suspended from a chain or thread (silk, linen, hemp) 30 to 80 centimeters long, depending on the particular sensitivity of the experimenter and the object of the research. The movements of these instruments—raising or lowering of the tip of the rod in the operator’s hands; pendular, circular, dextrorse, sinistrorse, or elliptical oscillations of the pendulum—are said to indicate the presence, depth, nature, and particular characteristics of the object of the search, according to an interpretive code often lacking rational justification, empirically established, and frequently varying from one experimenter to another in the most detailed responses. The same multiplicity of methods and precautions prescribed, deemed essential for the successful outcome of experiments, appear more as empirical and personal precepts than as rationally motivated scientific rules.
As for the interpretation of the phenomena, one of the exponents of radiesthesia, Abbot Mermet (v. BIBLICA), posits as fundamental postulates that: a) all bodies, without exception, constantly emit waves or radiations; b) the human body, entering these fields of influence, is the site of nervous reactions, specifically currents that channel through the right hand; c) if a suitable object, such as a rod or pendulum, is held in the hand, the invisible flow manifests itself through the movements it imprints on this indicator. For radiesthetists, these postulates are also intended to serve as explanatory hypotheses of the phenomena. The immediate cause of the movement of the detecting instruments during research is said to be the involuntary muscular contractions of the operator, provoked by the discharge of the presumed radiations on his nervous system, rather than automatic shifts of the rod or pendulum due to a direct stimulation by the forces emanating from the object of the search.
It is not possible to render an absolute judgment on the value of radiesthesia in relation to the subjectivity of the methods and the questionable certainty of the results obtained. A practice on the fringes of the occult and the magical, often carried out by individuals lacking solid doctrinal preparation and incapable of rigorous objective criticism, is frequently tainted by ignorance, fantasy, carelessness, and falsification. Such a judgment applies particularly to the more extraordinary and impressive applications of radiesthesia, such as the search for persons or their qualities through radiesthetic examination of handwriting or photographs, or the location of persons or things based on pendular responses to topographic maps, etc.; in such activities, even the supposed direct radiating action of the object on the operator cannot explain the results. In these cases, if the facts are truly documentable, it would seem more plausible to admit the intervention of preternatural factors, especially where the revelation concerns future contingent events (v. METAPSYCHICS). A more affirmative stance may be taken regarding the more minor and commonplace facts, such as underground water or mineral prospecting.
It must be acknowledged, moreover, that there exists a series of practical cases in which the reality of the asserted facts can be documented, and skilled experimenters, whose perfect good faith and scientific integrity cannot be denied, do indeed succeed in their practical aims—whether locating deep water veins, mineral deposits, or finding lost persons or things, or diagnosing human ailments. Since, however, these involve particular faculties that are not ordinary to all men (extrasensory perception or ESP, in the terminology adopted by Duke University in Durham, North Carolina, for the cognitive power underlying clairvoyance phenomena in general), even if present in all men in embryo and capable of being developed through practice, it is understandable that the verification and demonstration of these facts cannot attain the level of ordinary scientific experimentation and leave ample room for doubt and contradictory interpretations.
The history of radiesthesia extends back to the most ancient times, blending with Oriental magical rites and the divinatory practices of pagan antiquity. An orderly and serious study of rabdomancy probably cannot be traced back before the 16th century, with the work of the Abbé L. de Vallemont: *La physique occulte ou traité de la baguette divinatoire*, Paris 1693. In 1913, the pendulum reappeared officially on the scene of radiesthesia through the work of Mermet at the Radiesthetic Congress in Paris. Today, particularly in Germany, France, and Switzerland, thousands of radiesthetists are organized into national associations and gather at periodic congresses.
Catholic teaching neither condemns nor forbids the practice of dowsing, except where it is practised in a particular form or with certain aims (for example, the divination of the future or the attainment of results humanly impossible) which would involve superstition (cf. superstition). For reasons of decency or prestige or to avoid occasions of scandal, the Church forbids clerics and religious the practice of those forms of dowsing which have as their object the circumstances and qualities of human persons (diagnosis and cure of diseases, investigations into intellectual and moral qualities, duration of life, circumstances and time of death, etc.; decree of the Holy Office, 19 May 1942, AAS, 34 [1942], p. 148, and the commentaries of A. Willwoll and J. Creusen in Periodica de re morali canonica et liturgica, 31 [1942], pp. 280 ff.).
Giuseppe De Ninno