THE CIRCULATION OF INVISIBLE KNOWLEDGES :

DOWSING AT THE TURN OF 18TH CENTURY

Koen Vermeir

Preamble : microscopic studies in Holland

During the last days of May 1696, the famous Dutch microscopist Antoni van Leeuwenhoek (1632-1723) was occupied peering through his microscope at a piece of hazel rod. After careful scrutiny and consideration, he concluded that hazel ‘has a particularly large amount of very little horizontal vessels’. Van Leeuwenhoek had been drawn to a closer study of hazel and other kinds of wood, because of a particular controversy in his environment. Indeed, some of his friends were engaged in a debate on divination, and they had called for his help to resolve the controversy. In the milieu of Dutch publishers and journalists, the divination rod or the dowsing rod was the subject of fierce debate at the end of the seventeenth century. Cornelius Van Beughem, a respected publisher, councillor of the Dutch city of Emmerik and a friend of the journal editor Pieter Rabus, had demonstrated his capacities for divination at the latter’s house. At first sceptical, Rabus changed his mind when it turned out – in the course of the demonstration – that his wife, Elisabeth Ostens, also had the ‘gift’ of divining, and could find hidden gold and silver. This practice spread rapidly : it was demonstrated in many households, in Amsterdam and other Dutch cities, as well as at the home of Van Leeuwenhoek in Delft. The demonstration in Delft, held in the presence of five other eminent witnesses, turned out very successfully, and convinced Van Leeuwenhoek to study the matter in more depth. This controversy gives us a beautiful picture of the ways science was practiced and disseminated in the Low Countries at the turn of the 17th century. We get an idea of the scientific demonstrations going on in Dutch bourgeois domestic settings, the personal contacts by which scientific claims were transferred, as well as the ways in which controversies were initiated and perpetuated. A controversy, sometimes intense and venomous, between advocates and opponents, developed in local journal publications, such as Ramus own journal : De Boekzaal, as well as in pamphlets, enrolling the local doctors and savants.

Lyons : the origin of a controversy

These relatively small scale events in Holland were in fact the reverberations of a much larger controversy, which came to its height in Paris three years before, in 1693. Let us widen our scope and trace back the development of this controversy. This will give us the chance to get an intimate view on the way science was practiced in the French capital. Furthermore, it is an excellent case to study the difference in reception of contested knowledge claims between Paris and other European capitals. But in order to get a grip on the case, we have to go even further south, to the French provinces. Indeed, the controversy only flooded the French Capital after savants in Paris had received letters about a curious feat of divination that had taken place in Lyons. On the 5th of July 1692, the officials of Lyons were confronted with a difficult murder case and they made little progress. One of the neighbours of the victims, however, remembered a farmer from the Dauphiné, who had gained some local reputation for his capacity to find criminals. It was told that he could not only find water and hidden treasures by means of a divining rod, but could trace criminals as well. This farmer, Jacques Aymar, was given a chance to prove his merit by the Royal prosecutor, and was brought to the scène of the crime so that he could ‘take his impression’. At the place where the corpses had been found, Aymar was ‘affected’, felt feverish and the forked stick he held turned rapidly. After this, he went out, traversed the streets of Lyons to the gates of the city, and a long journey began. I cannot go into all the details of this closely recorded journey, but let me point out some elements of it. In the beginning, Aymar sometimes found the traces of two, then of three persons, but this uncertainty came to an end when the traces led him to the house of a gardener. There, he claimed, the offenders had sat around a table and had drunk from one of the three bottles in the room, because when he came near this bottle, his rod turned visibly. This was confirmed by the children of the gardener, who had kept it secret until then, because they had been afraid that their father would have punished them for letting the door open. They also gave a description of the three men, who had sneaked into the house and had drunk from the bottle. Bolstered by this success, Aymar and his escort continued their journey, over roads and rivers, and Aymar went ashore in every small port where the criminals had interrupted their travel. Furthermore, to the astonishment of their hosts and the spectators, he was able to point out the beds in which they had slept, the tables on which they had eaten, the plates and glasses they had touched. They arrived in a garrison town, Camp de Sablon, where the trace seemed much stronger, but afraid of maltreatment by the soldiers, Aymar did not dare to use the dowsing rod openly. They went back to Lyons to get letters of recommendation, but when they returned, the criminals had already fled. They continued the chase, for miles and miles, in the same manner as before, tracing the steps and actions of the fugitives, and, finally, stopped before the gates of the prison in Beaucaire. There, fifteen prisoners were presented to Aymar, and his rod twitched in front of a hunchback who had been imprisoned for petty theft one hour earlier. The hunchback denied any connection to the crime in Lyons, he even claimed to have never been in Lyons at all, but brought back along the road they had followed earlier, and being recognised by all the hosts of the inns where he had slept, by the children of the gardener and by other bystanders, he confessed his complicity in the murder case. This feat started a huge controversy on the workings of the divining rod, and on how it could be explained philosophically. In this paper, I will concentrate on the circulation of contested knowledge claims. The controversy on dowsing is an excellent case to trace the origin, the dispersion and reception of material objects, embodied practices and abstract knowledge. Especially those contested knowledge claims, that ultimately failed to become scientific consensus, are elucidating to uncover the mechanisms of circulation. At first, the strangeness of the phenomena gives us a kind of ‘anthropological’ detachment from the case. Second, this approach shows that many knowledge claims did circulate before they failed. Focussing only on successful practices makes the history of science consolidate positivist intuitions, and suggests that circulation of ‘true claims’ or ‘working practices’ need no further explanation. Third, the resistance by contemporaries, at each stage of the circulation, makes the processes of circulation visible for the historian. Finally, to discover what allows practices or knowledge to circulate, opens perspectives to find out why certain knowledge claims gain universal acceptance, throwing new light on the much acclaimed ‘universality of scientific knowledge’.

Trials in Lyons

Back in Lyons, the rumours of so marvellous a feat attracted many curious people and savants. They visited Aymar, interviewed him, examined him and did experiments to find out how this curious phenomenon could have happened. They went back to the wine cave, for instance, to analyse the effects on the dowsing rod. They also hid the murder weapon, a gardening tool, between similar ones, they buried them under the ground, they had Aymar even blindfolded, but he was always able to point out the actual murder weapon with his rod. All this happened in the presence of witnesses with a ‘sceptical attitude and clear discernment’, such as Monsieur de Bérulle, the lieutenant of the police, the Royal prosecutor (M. de Vanini) and the count of Varax. On another evening, they brought in other credible men such as Monsieur Grimaut, director of customs, and a young prosecutor, Besson, both of whom claimed to possess the capacity of dowsing (la vertu de la Baguette). The divining rod also started turning in their hands when they came at the scene of the crime. Again, Aymar was subjected to tests and experiments for hours, in the presence of physicians who examined his bodily symptoms. Aymar clearly had a fever, but also the other men who tried out the rod experienced bodily effects. When the witnesses felt Grimaut’s hand, for instance, they felt that his veins were throbbing extraordinarily. All this was testified by ‘persons of consideration and merit’, and related in a letter sent to abbé Bignon in Paris. Panthot, dean of the medical faculty of Lyon, independently gave a similar account, and he would later write a book on this case with a medical explanation of the events. After these tests, Aymar was sent south again to find the other murderers, this time accompanied by archers. In a similar way as before, they travelled further to Toulon, at the Mediterranean, where Aymar told that the criminals had boarded a ship. Undaunted, the company chartered their own ship and followed the trace on the see, till they came at the border with Italy. Here, the criminals were beyond the limits of the jurisdiction, however, and the company had to return empty-handedly. At the same time, the hunchback was tried and convicted in Lyons by 30 judges. When Aymar was back in Lyons, the convicted hunchback was executed by being broken alive. Afterwards, diverse savants came to see Aymar and more experiments were staged. Garnier, who got his doctorate in medicine at Montpellier, the leading medical department of the country, was witness of the experiments at the house of the head of the police. Aymar had to find thieves, hidden gold, etc., and he accomplished this without great effort. He was also interrogated by savants about the diverse powers of the dowsing rod. These experiments took place in an informal domestic setting. At one occasion, the wife of the police officer wittily stole the purse of M. Puget, one of the witnesses present, and asked Aymar to clarify the crime that had just taken place. When Aymar could not find anything, he coldly remarked that he could only trace real crimes. Notwithstanding this little conflict, Aymar provided entertainment in a provincial salon culture that, in general, was well-disposed towards him. Aymar was clearly a cause of wonder and in the province, noble entertainment, scientific experiment and judicial trials coincided. Aymar made a veritable impression with his extraordinary talents and a witness wrote in a letter to Bourdelot, physician of the duchess of Burgundy, in very positive and amiable terms about Aymar as ‘our villager’ or ‘the good Villager’. Not everyone was convinced of Aymar’s feats, however. The local bishop, Camus, was worried about the religious legitimacy of these divining practices, and had written to his former student Le Brun for advice. Subsequently, Le Brun did some tests and experiments with dowsers (mostly female dowsers, who had come to him because they were afraid that their capacities were not what one would call orthodox). He in turn reported his findings to the philosophical luminary of his order, Malebranche. The latter condemned the practice and attributed the successes of the divining rod to the involvement of demons. Buttressed by Malbranche’s letters, Le Brun became one of the major opponents of dowsing. In this, he was supported by Chirac, Professor of Medicine in Montpellier, who similarly condemned the use of the divining rod.

Circulation of news, bodies, instruments and knowledge claims

The early stages of the controversy gained momentum by means of local correspondence networks. More and more people became involved, each time in higher echelons. Patronage systems were crucial, and people tried to climb in the social hierarchy by reporting curious phenomena to, for instance, the supreme judge, the bishop or a nobleman. The dowsing case was an event with potential, as it combined entertainment, scientific interest, curiosity, as well as utility – an extremely powerful combination at the time. Chauvin, in a letter to Mme la marquise de Senozan (1692), wrote that it was ‘a discovery, so useful for the conservation of the good and of the life of man.’ But the discussion did not stay confined to the provincial level. Letters were also written to savants, courtiers and the nobility in Paris. These letters were circulated at court, where they caused much pleasure and divertissement. Some of these letters were later published. These pamphlets were in their turn followed by a number of books reporting and interpreting the case. At first, provincial publishers, especially in Lyons and Grenoble, took advantage of the case and tried to expand their readership. For the local authors and physicians, it was a way of advertising both their wit, erudition and their medical expertise to a broader public, and the case presented a chance to win wealthier and more powerful patrons. Parisian savants eagerly engaged in the controversy, and pamphlets were published in the leading Parisian journals (such as the Mercure Galant, the Lettres Historiques, the Mercure Historique et Politique and the Journal des Sçavans). At first, opinion in Paris was based on the accounts of eyewitnesses. By lack of first hand experience, the eager public relied on virtual witnessing and analogical demonstrations. But then, Aymar himself was called to Paris, by no-one less than Henri-Jules de Bourbon, Prince de Condé. Henri-Jules de Bourbon was first prince of the blood, son of the Grand Condé, and one of the foremost noblemen of the country. He had received a progressive education by Jacques Sauveur, M. de La Bruyère and his Jesuit tutors, focussing on the philosophical and scientific principles of Cartesianism. Later, instead of going into the military, he concentrated on the arts and sciences and contributed to the aristocratic passion for Cartesiansim which suffused polite society at the time. No doubt, this contributed to his reputation of being an able courtier and an entertaining host. In order to assuage his scientific interests as well as exploit the entertaining potential involved, this Prince decided to get Aymar to Paris. On the 21st of January, 1693, Aymar arrived in Paris and was lodged with the concierge of the Condé’s mansion. Following Aymar in his trials and tribulations, will allow us to penetrate the houses of Parisian nobles, and to give an account of how scientific demonstrations and experiments were performed in their salons. It also illustrates how illustrate how their passion for science was driven by intrinsic interest, practical concerns and a penchant for spectacle. Furthermore, it elucidates how science was publicised in broadsheets, journals, and books in the capital, and how these accounts affected the growing international appeal of the case.

Experiments in Paris

The prince started the trial in his house by conducting Aymar to a cabinet, where gold was hidden at several places. Aymar’s capacity to find the precious metal seemed troubled, however, because of the many golden ornaments and decorations of the walls. So he was taken to the garden, where he had to find and distinguish different buried metals. Unfortunately, he failed to get it right. After this miscarriage, the prince confronted him with his daughter, Mademoiselle de Condé, from whom two small golden candleholders had been stolen. Aymar led them through the whole house to the stables, then through the little gateway beyond the dunghill to the quays of Paris, until they reached the house of a goldsmith. The goldsmith denied having seen such candleholders before, however, and the suspicion fell on Aymar himself instead. After these events, Aymar was presented in the houses of many other noblemen and dignitaries, where he had to solve thefts and find hidden gold or silver. Amongst others, he was brought to the duchess of Hannover, who resided at the hôtel de Guise, to the mansion of M. de Gourville, and the castle of Chantilly, the residence of the Condés. Taking advantage of the presence of this ‘celebrity’, the parties amused themselves by subjecting Aymar to ever more tests. At all these places, similar trials were performed – and Aymar seemed to fail each time in turn. But apparently, the noblemen could not get enough of Aymar’s failures. Tests were repeated over and over again (often with deception and trickery involved) in all the most distinguished locations of Paris. These reports of an endless continuation of trials and experiments make one wonder at the purpose they might have served. The various thefts that Aymar had to solve, some of them taken place several months of even years earlier, seemed conjured up as a pretext to see the celebrity at work at yet another place. Indeed, with the performances of Aymar in these diverse noble settings, we see a veritable circulation of embodied knowledge and practice – not so much of the practice of divining, however, that was in a sorry state – but rather in the circulation of etiquette, genteel wit and courtly gifts, when friends and family of the Prince were given the chance to stage their own spectacle. After his umpteenth misfortune of Aymar, the noblemen were still not satisfied. De Condé entrusted M. Robert, Royal Prosecutor at the Castle in Paris, with further tests. Also the Académie royale des Sciences did experiments with Aymar in the Library and the Gardens of the King, on the invitation of Jean-Baptiste Colbert, marquis de Torcy and one of Louis the XIVth most able ministers. These experiments took place in private domestic settings, in aristocratic cabinets, royal libraries and princely gardens, and although they sometimes led the party on the streets of Paris, the reports always give an impression of salonfähigkeit – here in the sense of involving a small group of elect participants and observers. What is more, the actual experiments performed in Paris bear a striking resemblance to those performed in the province. The only difference is that the noblemen rhetorically hint at a higher level of sophistication involved. But how credible is it that the provincial savants had been so very naive in their experiments ? There were various good reasons, also for them, to aspire to the highest standards of experiment in testing Aymar’s capacities, since there was a lot at stake (including the life of innocent people). We, as well as the participants, are confronted with the paradox : why did the divining rod work in the Province, and not in Paris ? The sophistication of the nobility was not so much a matter of accuracy and better testing, it was rather an expression of courtly wit and amusement. In the whole account, the fun provoked by trying to outwit Aymar is perceptible. The reports suggest that Aymar only perceived the evident clues, and even these he often misses. The texts rhetorically thematise provincial and countrified lumpishness and oppose it to courtly finesse. It should be remembered that de Condé was widely known for his eccentricity, his malicious spirit and his practical jokes (he was known to be a terror for his wife and children), and this throws another light on the experiments. But these practical jokes were an indispensable part of courtly amusement and spectacle, and did not contradict good manners or scientific spirit. In contrast, Aymar was found to lack manners in the City. Indeed, a conspicuous shift had happened in the portrayal of Aymar himself : while the provincial authors described Aymar as a good and honest man, the accounts of his exploits in Paris were phrased in different terms, terms like gluttony, opportunism, corruptness, bribability, cunning and immorality. His searches with the rod were described as mysterious and cunning behaviour [manéges mystérieux]. Furthermore, he was depicted as an immoral person, always in pursuit of profit. When Aymar had to find a thief for M. Ferouillard, a wealthy merchant, for instance, it was reported that he guided Ferouillard together with a whole party of interested neighbours and visitors through the streets of Paris, until Aymar declared that he was tired. The whole company was then served dinner on Ferouillard’s costs. When the search was continued the next day, only Ferouillard was left to accompany Aymar, and the search itself came to nothing. Tales were also told concerning his discretion : when M. de Briol had asked Aymar to find out whether his mistress was still faithful to him, Aymar seems to have been indiscrete towards the servants and he tried to bribe the mistress. Many inauspicious and incriminating rumours were spread in town, referring to Aymar’s bad behaviour and waning repute. Class differences conflicted, were subtly played at and were abused in the ‘scientific’ demonstrations. Drawing on evident class differences, the reports of the nobility can be read as a eulogy of their own wits. Merchants could be taken in, and could be persuaded to pay the entertainment of the company, but the noblemen mercilessly exposed the impostor.

The province versus the capital

It is clear that contested knowledge claims regarding divination were very differently received in the French capital as compared to the province. This was made clear and invigorated by the Parisians : they accused the provincial savants of superstition, denied them the status as credible witnesses and commented on their manners. When the provincial physician Chauvin (a defender of Aymar), wrote an angry letter in a Parisian journal, as a reaction to his being rejected as a credible witness and to accusations of incompetence, his letters were not included in a collected volume. According to Le Brun, he clearly lacked the necessary manners for being taken seriously in the capital. It was not so much that ‘popular science’ in the sense of ‘popular culture’ was rejected here, as if these were categories with a fixed content. Instead, we see here an instance in which ‘the popular’ was constructed. Before, the use of the divining rod had been defended as well as condemned by many authorities – notably, Boyle had encouraged the study of dowsing as a scientific programme. Now, we see a demarcation in the make, in which dowsing becomes associated with ‘superstition’ in the two meanings present at the time, as illegitimate religion and excessive credulity, to which countrymen were particularly vulnerable. Unexpectedly, instead of a triumphal procession in the capital, the provincial savants had experienced dismissal. The Parisian nobility rhetorically established different standards, excluding the provincials from any claim to knowledge. It was made clear that science could only be established in the Parisian salons, not in the provincial fields. How do we explain these paradoxical results ? If experiments were not decisive, and agreement on them could not easily be reached, why was there such a clear cut difference between the results in the province and the capital ? Neither seems there to have been a theoretical predisposition for or against dowsing, which might have determined the difference in outcome between the province and the capital. The same theories were used, sometimes in favour of, sometimes against the possibility of dowsing. De Condé, for instance, was a famous Cartesian, but proponents of dowsing used Cartesian explanations to prove that it was a natural phenomenon. One of the reasons of the split between judgements and attitudes in the province and the capital should be sought in the geopolitics of knowledge. The specific pre-existing distribution of trust, shaped by long term geographical, political, social and other circumstances, is crucial in shaping the circulation and reception of knowledge claims. In Parisian polite society, ‘scientific wonders’ compelled amazement, affirmation and belief, while ‘unscientific wonders’ required subtle derision, scepticism and rejection. The distinction between both kinds of wonders is of course not of a universal nature, as this very same elite contributed in establishing what was scientific and what was not. In this way, such ‘demarcation exercises’ resembled the establishment of other kinds of courtly etiquette. Knowing how to deal with them marked your social status. But, as we will see, provincials did not reconcile themselves to this situation.

The circulation of contested knowledge claims

To recapitulate the theme of this paper : circulation. At first, before looking at the circulation itself, we have to look at the locations where the claims and practices took shape. In this case, the sources make it possible to pay close attention to the sites of knowledge, and the story brought us from the dangerous banks of the Rhône and the vineyards of the Lyonnais to the intimate interior of princely cabinets and Royal libraries in Paris. These places, the locations where knowledge claims were constructed, tested and rejected, played a crucial role in the debate. In this case, these sites were not laboratories, but rather outdoor locations or the lived spaces of everyday life. Nevertheless, they were carefully prepared and adapted in order to become a site of experiment – or better, a site of ‘experience’. On the way, the meaning of dowsing also changed : from a way to find water to a means to track criminals ; from a ‘most useful instrument’, to a diabolic cunning, and then again, to a malicious trick. In the beginning of the circulation, no network in any formal sense was present or established. There were only small, already existing personal networks of friend, student-teacher or patronage relationships. The more the controversy gained ground, however, the more it became disseminated over more well-trodden paths. More established networks became more important, such as official institutions, and in particular the publishing network. The early stages of the controversy were already published on provincial presses, and set the stage of much of the controversy. Witnesses had published their account of the events, originally written in a letter to their patrons, to reach a wider audience. Physicians rushed into print with their explanations of the events, using the then fashionable concepts of Cartesianism. The controversy caught the attention of Parisian savants originally by the dissemination of letters to patrons and friends (to this stage publications little contributed), and later by articles in the popular Parisian journals. The books of local physicians shaped the conceptual approach of the Parisian savants, however, and the most important books on the controversy – Vallemont and Le Brun – extensively drew on the work previously published in the province. At the time, letters, journal articles and published books all competed with one another for the hegemony of the dissemination of information and knowledge claims. In this case, as I have argued, it was in particular the distribution of trust which proved crucial for the acceptance or rejection of knowledge claims. In the capital, the basic structures of trust were disrupted by an indistinguishable mixture of scientific scepticism and aristocratic wit. The lack of trust from the capital towards the province, however, was returned when the provincial savants and their supporters refused to accept the insults from the Parisians and the conclusions of the Prince de Condé. The provincial savants, and those who had backed up Aymar, refused their role as superstitious and backward provincials in the courtly play of credulity and incredulity. The controversy between Chauvin (a provincial physician) and Le Brun (a theologian based in Paris) in the Mercure Gallant, was an early indication of the resistance of the provincial intellectuals. After the experiments of the Prince de Condé, also a theoretical opposition was voiced : Renaud explicitly framed this opposition in the terms provincial versus capital. He and others took a theoretical position that explained Aymar’s failures in Paris, as well as his successes in the province. But by doing this, they challenged the universality of scientific knowledge.

The universality and locality of knowledge

This controversy is an excellent case to study the circulation of contested knowledge claims ; not only because practices, materials and knowledge claims indeed travelled over serious distances through widely varying places and contexts, but particularly because what the actors thought that circulated, and how this circulation affected ‘experimental and natural philosophy’, was central to the debate. Peter Dear has argued that the change from ‘experience’ to ‘experiment’ was parallel to a change from the Aristotelian belief in a ‘general order of nature’ to the modern notion of the ‘universality of nature’. During the 17th century, Dear argues, the idea was developed that a singular, historical event experiment could justify a universal knowledge claim. This idea found its fullest development in Newton’s work and methodological reflections. For this to work, however, one must presuppose the universality of nature itself. As it was stated in the Preface of Newton’s Principia : “All Philosophy is based on this Rule [i.e. that nature acts the same everywhere] : inasmuch as, if it is taken away, there is then nothing we can affirm about things universally” As Lorraine Daston, Katy Park and others have shown, the Aristotelian conception of an ‘ordinary course of nature’ allowed for the category of exceptional occurrences, of extra-ordinary but still natural phenomena : the ‘preternatural’. These were hindrances or interruptions, errors or digressions from the norm. It also allowed for exotic regions (the borders of the earth, or the French provinces), where things could be very different. This is not the case anymore in a uniform conception of nature. There are no exceptions. While, at the end of the 17th century, the constructed singular instances of ‘crucial experiments’ were enlisted in the service of the universality of nature, natural philosophers excluded other ‘particulars’, or explained them away as (human or demonic) artifices. In the case of the divining rod, we see this happening. Preternatural explanations alluding to a capricious nature are excluded. Therefore, it was always repeated in this debate on divining, by theologians as well as naturalists, that for a phenomenon to be natural, ‘it has to work in a constant and uniform way in similar circumstances.’ Dowsing had always been problematic with respect to uniformity and universality. Since only some persons had the ‘gift’ of dowsing, it was a suspect phenomenon. The Prince de Condé assumed that nature always acts the same, given similar circumstances, and he believed in the universality of knowledge about nature. Therefore, for him, some experimental trials in Paris could establish whether a phenomenon does or does not exist. If Aymar fails in the trials, he is a fraud. Theologians, for their part, believed in the success of Aymar and others, as their feats were well attested. But the phenomenon could not be ‘natural’ and they explained it as an artifice of the devil, with whom the diviner had an implicit pact. Supporters of dowsing took another view, however. They did not directly contest the notion of the universality of nature. They made clear, however, that universal knowledge claims always had the – often implicit – qualification : in similar circumstances (ceteris paribus). Barbara Shapiro has noted that the epistemological status of ‘circumstances’ surrounding ‘matters of fact’ was left unexamined in the 17th century. In this case, however, all sides of the debate stressed that nature ‘has to work in a constant and uniform way in similar circumstances’ and the status of these circumstances was firmly discussed. If one recognises the inherent flexibility of “similar circumstances”, if one accepts that claims to ‘similarity’ can always be contested, then, one gives credit to the local nature of all practices and knowledge claims, subverting claims to universality. In this way, the provincial physicians and other supporters of Aymar argued for the essential local nature of practices and the related knowledge claims. They tried to explain how Aymar could have succeeded in the province and why he failed in Paris, and they developed a rudimentary epistemology of circulation. They argued that ‘circumstances’ might change in a significant way when a person, an instrument or a practice was circulated. There are always ‘obstacles’ and ‘circumstances’ that prevent a situation from being identical with another, and by stressing these ‘obstacles’, one might say that they carried on the ‘preternatural philosophy’ with other means. In order to bolster their claim, the defenders of dowsing made use of a subtle epistemology of the body. Indeed, what proved crucial for the evolution of the controversy was the circulation of Aymar himself. When the rumours about Aymar’s curious accomplishments spread, some tests were performed with other dowsers (Le Brun did some tests at the observatoire in Paris). Nonetheless, even the Prince de Condé recognised the force of experimenting with Aymar himself, instead of with a substitute. The use of a substitute would make the implicit claim of similar circumstances virtually untenable, and would make his experiments vulnerable for critique and opposition. Therefore, like a scientific instrument, Aymar was circulated, but he also had to be calibrated, as the performance of instruments often depends on the material of the instrument and the given circumstances. Vallemont explicitly compared the body of the dowser (and of Aymar in particular) with a multitude of scientific instruments, including a barometer and a hydrometer. Pointing out the difficulties with the circulation of Aymar could then also draw on the better known difficulties with the circulation of precision instruments (think only of the difficulties to keep a clock to run correctly during long voyages at sea). Nevertheless, also the difficulties with instruments were often neglected at the time, and it was easy to attribute ‘anomalous’ measurements or phenomena to the unreliability of the witnesses instead - especially if these were far away. The provincial savants countered this with a more subtle model of the body. They wondered how a body changes when transported to different environments, and although they compared the body to a precision scientific instrument, they were also aware that a body is more complex than a mere mechanical tool. They acknowledged the role of ‘psychosomatic’ phenomena, and they wondered how the body changes in different social and psychical contexts. Nervousness and other emotions could influence the capacity of dowsing, and special care should be taken when experiments were made. According to them, it was obvious that Ayar did not perform well in the stressful settings of the Parisian trials. Stressful, exactly because of the class differences and the hostility Aymar felt. Vallemont even went so far as to criticise the experimental method of the Prince de Condé, pleading for a more subtle understanding of experimenting, which would not deny or obscure the existence of uncontrollable boundary conditions, but which would take them into account when evaluating a phenomenon. For him, as I have shown, this amounted to taking serious and giving more credence to the multiplicity and cumulativeness of lived experience.

How to end the controversy ?

In order to bring to halt the fad about dowsing, the Prince de Condé had published the results of his trial in the Mercure Galant. Also other intellectual luminaries, such as Malebranche, Menestrier and even Fontenelle, in his function of secretary of the Académie, had published comments and condemnations of the practice. Notwithstanding all these communiqués, the province ignored them. After Aymar’s defamation in the capital, he retreated to the province where he kept being in demand. Even the provincial officials, brushing aside the opinions of their Parisian superiors, often appealed to him to solve murder cases and the like. In 1706, for instance, Aymar was still active in Lyons and the environment. We know this from a letter from Claude Brossette, in many ways the leading intellectual figure in Lyons. In a letter of 25 September 1706 to his friend Boileau Despréaux, the leader of the anciens during the Querelle, in Paris, he remarked that the previous day he had seen Jaques Aymar, ‘l’homme à la Baguette’, a man whose natural gifts were not easy to explain. He had talked with Aymar, and reported on the emotions and affection the dowser felt when practicing his ‘craft’. Not the dowsing rod, he stressed, but the body of the dowser seemed crucial for the phenomenon. If Boileau wanted to hear more, Brossette would be happy to provide him with more information. Boileau, however, wryly answered that he was surprised to find Brossette occupied with such trifles and that he believed in such drivel. Aymar had long before been unmasked in Paris. Notwithstanding the recent centralisation of the state and the increasingly formalised networks with the capital, the provincial towns and the countryside kept their autonomy. This is why – although the distinction province-capital has proved relatively viable for my analysis – the model of a centre and a periphery seems less apt to fit the case. Both the province and the city were important in the controversy, and they were co-constitutive in the circulation of knowledge claims. When the people from the capital did not want to accept its accounts, practices and theories, the provincials in turn repudiated the judgement of the capital, further developing its own approach. In this case, the capital did not win out. Practices and knowledge claims continued to circulate – in the province itself, but also abroad. In particular, it turns out that de distribution of book-publishing crucially shaped the knowledge economy in Early Modern Europe (more than experiments performed by the nobility, or ideas voiced in the leading journals). Popularity and the right publishing strategy seemed to be more important than social status, religious correctness or intellectual profundity. If we widen our scope again, we can see the broader circulation of knowledge claims regarding dowsing. Indeed, in the years after the Aymar’s curious feats in the French province, many controversies popped up throughout Europe in which dowsing was taken seriously. Vallemont’s book was at the root of these movements. Many editions appeared in Paris, but also in Amsterdam and Germany. As I have related at the start of this paper, his book caused a revival of the dowsing controversy in the Low Countries a few years later, where natural philosophers were puzzled by the phenomenon. Similar events occurred at many places in Germany, but there the theological critique took more ground and was especially directed against Vallemont’s materialist explanations.

Epilogue : reverberations in 18th century London

Let me, to conclude, focus more closely on what happened in London a few years later. Here, during a revival of the dowsing case in 1710, we see a markedly different reception than in other places in Europe. In a new Tatler-style journal, The Visions of Sir Heister Ryley, authored by the projector Charles Povey, Aymar’s story was once more recounted. In the issue of August 28, 1710, Povey described : ‘The Case of James Aymer, a Frenchman, who pretended to find out all the Faults and Actions of men, be they never so secret, only by the Motion of a pretended Wand, which he always carryed about him. Never did any thing make a greater Noise, or occasion the Writing of so many Books about the Miracles this Person was said to do.’ Povey included several stories about Aymar’s feats and dwelled on the possible social and political uses of such an – alas illusionary – rod. In the following issue (of September 8, 1710), he told, as he called it, ‘the full Discovery of the Cheat’. De Condé’s tests were presented as conclusive, and Vallemont dismissed as an enthusiast : ‘This sort of Philosophers, as well as the Unfolders of Prophecies, (for both of them are of the same Stamp) are a kind of Enthusiasts.’ The experimental approach, on the other hand, was received without question. But the reception of the dowsing controversy acquired also another explicit contemporary political meaning. Jonathan Swift appropriated Povey’s article, a few days after it appeared, in order to debunk an important politician : Lord Godolphin, the previous lord treasurer. On the 14th of October, he published ‘The Virtues of Sid Hamet the Magician’s Rod’. In this poem, Swift used all the associations of the ‘Magician’s Rod’, referring to the staff of lord treasurer Sidney Godolphin. In particular, he exploited all the possibilities provided in the recent journal issue. Povey had depicted Aymar as a cheat, who used his divining rod to scheme and make profit. If the rod would have been genuine, criminality would have been banned out of France forever. But as it turned out, Aymar was a swindle, pretending to tell justice, but he bribed the victims and his judgement was directed by those who gave most. This is a remarkable story, Povey noted, but he asserted that similar persons could be found in London : those who pretended to be honest judges, but gained considerable states by their frauds. Swift took these clues, and expanded on it in order to drag Godolphin through the mire. In his account, Godolphin used the ‘magical’ power of his treasurer’s rod in a similar way as Aymar : to bribe, to gain money, to subvert justice and to increase his political power. Both Aymar and Godolphin are presented as false conjurors, deluding the people by the dexterous motion of the wand. Politics and justice are depicted as the stage where illusionists have reign. This is the curious reception and appropriation of the circulation of knowledge claims about dowsing in Britain. Swift’s text caused another controversy : a French debate on natural philosophy, justice and theology had been converted into a small political riot in London. The figure of Lord Godolphin, previous Lord Treasurer of Britain, and Aymar, a French peasant and diviner, merged into one : an illusionist with his magician’s rod.