In the fall of 1640, the Toledo tribunal of the Spanish Inquisition was in the process of summing up its case against Antonio de Bolívar , a spiritual director accused of conspiring with one of his penitents to feign divine raptures and revelations—and demonic possessions.Footnote 1 Pretending to be possessed might seem a strange way of establishing a reputation for sanctity, but such afflictions were often interpreted as trials and tribulations visited upon “those whom the Lord wished to purify.”Footnote 2 In fact, the inquisitors took a keen interest in these claims of diabolism because they involved a particularly perplexing sign of demonic possession : the spontaneous ability to speak Latin without having studied the language. In this case, the penitent, repeatedly referred to as a “rustic person,” was reported to have spoken, read, and written Latin without any prior knowledge.Footnote 3

The inquisitors’ preoccupation with such feats is not surprising, given that the rustic who breaks into Latin was a familiar trope in the intellectual world of early modern Spain . The stock character was an uneducated peasant, typically described as a rústico labrador, or “rustic laborer,” and he had become a fixture in the learned discourse of the period as the prospect of the unlettered spontaneously speaking an unknown tongue raised a host of contentious issues in early modern European theology, natural philosophy, and medicine . Xenoglossy generated controversy because it fell within the realm of the preternatural, a category early modern Europeans reserved for phenomena that seemed to deviate from the established course of nature , without rising to the status of the supernatural.Footnote 4 In some cases such strange singularities were explained away as the effects of hidden natural causes, in others they were attributed to spirits or demons , but in all cases they demanded detailed natural philosophical analysis of the forces at work in order to ensure the proper classification of phenomena necessary for maintaining the early modern taxonomy of natural, preternatural, and supernatural causation.

The rústico labrador attracted especially intense interest in Spain because he stood at the intersection of two interrelated discourses: the critique of superstition and the analysis of melancholy . During the sixteenth century, Spaniards were both prolific and innovative in their treatment of these two topics, and the rústico labrador and his extraordinary linguistic feats became a popular object of analysis. Spanish presses produced not only a disproportionately large number of books on the reprobation of superstition and on the analysis of melancholy , but also the first vernacular treatises on both subjects, these being Martín de Castañega’s Tratado de supersticiones y hechicerías [Treatise on Superstitions and Witchcraft] (1529), and Andrés Velásquez’s Libro de la Melancholía [Book of Melancholy] (1585).Footnote 5

The two discourses overlapped because they were both deeply invested in the classificatory schema outlined above. The critique of superstition , for example, involved sorting through a wide range of popular techniques—from divination to love magic, to crop blessings and spells to bring rain—and extraordinary phenomena, such as the “evil eye,” faith healing , and xenoglossy , in order to determine what causes, if any, they had in the natural order. Barring such natural causation, and given that they lacked the supernatural power possessed by the sacraments of the Church, such practices were deemed preternatural and most likely demonic by a process of elimination. The analysis of melancholy cut across the tripartite taxonomy of natural, preternatural, and supernatural in a similar fashion. It was accorded supernatural attributes in the Neoplatonic theories of Marsilio Ficino , investigated as an instrument of demonic possession in anti-superstition treatises and manuals for exorcists, and analyzed in purely naturalistic terms in the researches of natural philosophers and medical practitioners for its ability to generate extraordinary capabilities, such as the ability to speak a previously unknown tongue.

The Latin orations of the rústico labrador, then, were prime fodder for the conceptual ferment surrounding the preternatural. The issue for Spanish theorists was whether the melancholy humor could produce such extraordinary abilities. If so, what were the precise physiological mechanisms for such remarkable feats? And if not, were they in reality the machinations of the devil ? This issue came to a head, as we shall see, in the debate between Juan Huarte de San Juan and Andrés Velásquez . Huarte’s Examen de ingenios [The Examination of Men’s Wits] (1575) sought to provide a naturalistic explanation for xenoglossy , a position that was contested by Velásquez in his Libro de la melancolía which argued that the phenomenon was demonic in origin. But this Iberian exchange was part of a long-running debate on melancholic genius which highlights the complex interrelationships between demonic agency and humoral physiology, and the difficulties inherent in drawing the boundaries between the natural and the supernatural.Footnote 6

The notion that melancholia could confer the ability to speak a previously unknown tongue, and other extraordinary capacities, such as the ability to poetize or prophesy , dates back to classical antiquity. The seminal work in the discourse on melancholic genius was a pseudo-Aristotelian text, the Problema XXX.1, in which the author makes a connection between black bile and heightened aptitude for politics, philosophy, and poetry.Footnote 7 The theory was that the black bile dominating the melancholic temperament was particularly susceptible to variations in temperature, and consequently melancholics were often buffeted between frenzy and torpor. However, at certain key points on this spectrum at which the individual temperament and environmental factors converged, it was held that melancholics could be capable of extraordinary feats.Footnote 8 The quintessential example of this syndrome was the prophetic gifts of the Sybils. We find examples of this type of naturalistic account in the works of later philosophers and physicians in the ancient world, such as Aretaeus of Cappadocia and Rufus of Ephesus , and as a general rule supernatural explanations of extraordinary mental states were rare among classical authors, with the exception of prophecy, which was often described as a divine gift.Footnote 9 During the Middle Ages , however, we do begin to see occasional references to demons as the cause of heightened cognitive abilities. In Islamic Spain , physicians Abulcasis and Avicenna both outlined demonological accounts of melancholic genius in which demons, either operating directly or as proximate causes, were credited with producing such effects.

The pendulum swung back in the opposite direction in the fifteenth century with a particularly influential analysis offered by Antonio Guainerio , a professor at the University of Padua . Guainerio’s explanation for melancholic genius represented a departure from the competing humoral and demonological accounts. Guainerio relied instead on the Platonic doctrine espoused in the Timaeus , whereby all intellectual souls are created with equal perfection, each possessed of all the knowledge it will ever have. The varying aptitudes displayed by actual, embodied souls were, according to Guainerio, determined by the vagaries and imperfections of the specific bodies they inhabited. Having forgotten their previous knowledge upon embodiment, intellectual souls were destined to undergo a process of remembering in which they sought to recover this lost understanding. This process, however, was hindered by the corporeal sense faculties. In a counter-intuitive move, Guainerio held that by impeding sense perception, the melancholic humor could actually facilitate the intellectual soul’s escape from its corporeal fetters and allow it to regain aspects of its original knowledge. It was through this process that melancholics sometimes displayed intellectual capacities, such as prophecy and xenoglossy , which they had not gained through experience.Footnote 10

The Renaissance witnessed a renewed interest in the problem of melancholic genius, most famously in Marsilio Ficino’s Neoplatonic revalorization of poetic melancholy, but it was in Spain that the question of melancholic genius received its most thorough airing, with the phenomenon of the rústico labrador becoming a favored case study. Several factors converged during this period to create a unique milieu conducive to such investigations. The numerous anti-superstition tracts being published in Spain provided a logical forum for discussing melancholic genius, since many purportedly superstitious practices involved attempts to foretell the future, and speaking a previously unknown tongue was taken to be a potential sign of demonic possession . Likewise, a sixteenth-century medical renaissance in Spain spawned a flood of treatises in which the subject of melancholy was treated extensively, as Spanish physicians debated the possible naturalistic or demonic explanations of various preternatural phenomena.Footnote 11

Spanish anti-superstition writers, by and large, came down on the demonic side of the debate. Pedro Ciruelo , for example, in his influential anti-superstition manual, Reprobación de las supersticiones y hechicerías [A Treatise Reproving All Superstitions and Forms of Witchcraft] (1530), took up the question of the rustic laborer and the ability to speak Latin or foretell the future, denouncing this possibility as indubitably demonic and an example of his “first rule” of good theology and philosophy that “all works of superstition come from evil spirits .”Footnote 12 In a similar vein, Juan Horozco y Covarrubias in his Tratado de verdadera y falsa prophecia [Treatise on True and False Prophecy] (1588) remarked upon the relationship of melancholy to xenoglossy , writing that “According to Aristotle , all studious men, and those he calls ‘heroes,’ are melancholics, and according to medical writers, melancholy often makes idiots into learned men, as with those many who have spoken Latin, composed verses, and foretold the future.”Footnote 13 Horozco then went on to dispute the possibility of a purely natural explanation for xenoglossy, bypassing contemporary physicians and harking back to the authority of medical authorities such as Avicenna , insisting that “those reports of melancholics speaking languages they have not studied is without doubt the work of the devil who is speaking through them. This is the understanding of the most illustrious masters of medicine , following Avicenna who affirms this clearly.”Footnote 14

Horozco’s position echoed that of Antonio de Torquemada , who in his anti-superstition treatise, Jardin de flores curiosas [Garden of Curious Flowers] (1575), had decried the tendencies of contemporary physicians to side with pagan philosophers in positing a humoral explanation for the heightened abilities of the rústico labrador:

And when these [pagan] philosophers were asked what beset those who were possessed by the devil , they said that it was a passion that proceeded from the melancholic humor, and that melancholy could produce these effects; and these days most physicians sustain and defend this same proposition, that when the devil speaks diverse tongues and puts delicate and elevated words in the mouth of a rustic laborer, that all of this is the product of the melancholic humor; but this is a manifest error.Footnote 15

As these complaints suggest, many sixteenth-century Spanish physicians did indeed take a more naturalistic approach to the question of melancholic genius. One account that had particular influence in Spain was propounded by Levinus Lemnius , a Catholic physician and monk from the Spanish Netherlands who took as his point of departure Guainerio’s emphasis on the Neoplatonic notion of reminisci, holding that the melancholic humor could stimulate heightened capabilities without demonic intervention. In his De miraculis occultis naturae [On the Hidden Miracles of Nature] (1559), Lemnius argued that perturbation of the humors could activate innate knowledge in such a way as to unlock hidden linguistic capabilities:

Therefore very often it may be by the bubbling of the humors, or by a vehement agitation of the spirits that certain inaudible voices and previously unknown languages are produced. Just as we see that sparks are produced by striking flint, it is innate in the human mind that it would be suitable and fitted for the purpose of perceiving the knowledge of things.Footnote 16

In the same chapter, Lemnius goes on to use several metaphors illustrating the way in which a melancholic disorder could engender heightened capabilities even while damaging the sensory faculties. He likens the process to a herb being crushed in order to liberate its essential fragrance and to a dormant fire covered in ashes that must be violently raked and turned over in order to free the heat and light within. Thus, the oppressive weight of the melancholy humor is able, paradoxically, to free the mind to remember its former nature .Footnote 17

Naturalistic analyses such as Lemnius’s found a receptive audience among physicians on the Iberian peninsula, as Spanish medicine was undergoing a period of exceptional innovation driven by a cohort of sixteenth-century Spanish physicians and natural philosophers who pioneered a medical renaissance characterized by the rediscovery of classical medical knowledge and an increasingly empirical approach. The study of Greco-Roman medicine —transmitted and elaborated upon by Jewish and Muslim scholars in medieval Spain —was particularly vibrant at the University of Alcalá , where both Juan Huarte and Andrés Velásquez received their medical training, but many other universities throughout Spain were similarly dedicated to recovering the medical wisdom of the ancients; the University of Valencia , for example, boasted eight chairs solely for the study of Galen and Hippocrates .Footnote 18 In addition to this medical humanism with its focus on the past and deference to classical tradition, Spanish medicine proved remarkably forward looking and innovative, especially in the field of anatomy. In the late fifteenth century, Spanish doctors received royal authorization to dissect corpses, and the presence of Vesalius at the court of Charles V further inspired the detailed, empirical study of the human body.Footnote 19 Out of these concerns emerged an intellectual culture with a decidedly naturalistic bent that combined an eclectic appropriation of traditional medical knowledge with an inductive, experimental clinical practice.

Given this context, it is not surprising that naturalistic, humoral explanations of extraordinary psychological states should become a topic of great interest, and indeed we see a variety of Spanish writers advancing such claims during this period. Francisco López de Villalobos , for example, court physician to King Ferdinand the Catholic , Charles V , and Philip II , asserted in his Summario de medicina [Summary of Medicine ] (1498) that mania resulting from an excess of melancholy could account for the ability to prophesy .Footnote 20 This form of melancholy , however, was not the natural state of the humor, according to Villalobos. It was instead a different kind of melancholy, made of “adust choler.”Footnote 21 This distinction was a crucial one because the term “melancholy” could refer to the normal bodily humor, black bile, or alternatively to the burnt, noxious bile known as adust choler, or atra bilis. For Villalobos and many other theorists, it was this adust choler, or “adust melancholy ,” as it was sometimes called, that could give rise to the sorts of extraordinary capabilities demonstrated by the rústico labrador.

Another author who countenanced the possibility of a natural explanation for xenoglossy was Alonso de Santa Cruz, who in his dialogue Dignotio et cura affectuum melancholicorum [Diagnosis and Cure for the Effects of Melancholy] (c.1569) had his chief interlocutor cite approvingly the opinions of Galen and Aristotle regarding the ability of melancholics to speak an unknown tongue and foretell the future.Footnote 22

The interest in melancholic genius in sixteenth-century Spain extended even to political thought, as a burgeoning genre of “medical politics” sought to extend the humoral analysis from the human body to the body politic. One such medico-political work was Bartolomeu Felippe’s Tractado del conseio y de los consejeros de los principes [Treatise on the Counsel and Counselors of Princes] (1584), wherein he held that melancholics could foretell the future through purely natural means. Felippe disputed the negative valoration of the melancholy humor put forth by fellow political theorist Fadrique Furió Ceriol , who after identifying the choleric and sanguine temperaments as those most suited for a prince, characterized melancholics as “vain, enemies of illustrious thoughts, malicious and superstitious.”Footnote 23 Felippe, after conceding that the melancholic temperament is less desirable than the choleric or sanguine, presented a defense of melancholy , pointing out that many authors have called it the “heroic temperament,” and insisting, citing Aristotle , that “many excellent men” have been melancholics. Felippe went on to argue that melancholics have a penchant for truth telling and that they often have the gift of prophecy and “many times they say what will come to pass.”Footnote 24

By the second half of the sixteenth century, the naturalizing tendency we have been examining had given rise to a number of works by physicians and natural philosophers that contained not just isolated analyses of melancholic genius, but rather exhibited a thoroughgoing somatic determinism which sought to explain man’s psychic and emotional states as the result of purely natural causation. Notable among such works were Oliva Sabuco de Nantes ’s Nueva filosofía de la naturaleza del hombre [New Philosophy of Human Nature] (1587), and Gómez Pereira’s Antoniana Margarita (1554),Footnote 25 and most importantly for our purposes, Juan Huarte de San Juan’s Examen de ingenios , which included an influential excursus on the phenomenon of the rústico labrador.

In the Examen, Huarte sought to account for the differences in aptitudes between humans for learning various arts and sciences in purely naturalistic terms. These aptitudes, or “ingenios,” were determined by one’s physiological makeup according to Huarte, and in the neo-Galenic paradigm in which he operated, that meant the precise balance of humors in a given body, these humors being blood, phlegm, yellow bile, and black bile. This unique balance, usually referred to as “temperament,” or “complexion,” gave rise to specific character traits: a surfeit of blood produced the sanguine character, whose disposition tended toward cheerfulness; an overabundance of phlegm gave rise to the calm, placid tendencies of the phlegmatic; an excess of yellow bile made the choleric energetic and quick to anger; and too much black bile fostered anxiety and depression in the melancholic. Within this paradigm, each of the humors in the human body corresponded to one of the four elements in nature : blood to air, phlegm to water, yellow bile to fire, and black bile to earth. And these in turn corresponded to the natural qualities, dry, wet, hot, and cold, so that the sanguine temperament was considered hot and moist, the phlegmatic cold and moist, the choleric hot and dry, and the melancholic cold and dry. To develop the relationship between microcosm and macrocosm further still, each humor was associated with a heavenly body and corresponding sign of the zodiac: blood with the planet Jupiter and the sign Libra, phlegm with the moon and the sign Virgo, yellow bile with the planet Mars and the sign Leo, and black bile with the planet Saturn and the sign Scorpio.Footnote 26 For the physician, health consisted in maintaining a balance among these humors in the microcosm of the individual human body according to its given temperament, and consequently a great deal of medieval and early modern medicine involved attempts to restore the proper balance of humors through the use of medications with qualities that countered the ones present in excess in the patient.Footnote 27

Huarte used this notion of temperament to launch an investigation into the genesis of psychological traits and cognitive abilities. He sought to provide an account of how specific humoral temperaments could give rise to particular aptitudes and in so doing inaugurated the discipline of differential psychology . The Examen achieved a good deal of success in the years immediately following its publication; it was brought out in various Spanish editions and quickly translated into French and Italian. Ultimately the book would be translated into English, German, Latin, and Dutch and read throughout Europe. Hand in hand with this success came controversy, however, given Huarte’s skepticism towards what he perceived as the miracle mongering of the common folk and his extreme naturalism, which was seen by some as casting doubt on the immortality of the soul. The Inquisition reviewed the Examen and a series of changes were mandated. These changes were implemented and an expurgated version published in 1594, shortly after Huarte’s death .Footnote 28

In chapter four of the Examen, Huarte took up what would prove to be one of the most controversial topics in a controversial book: whether the melancholic temperament could give rise to extraordinary intellectual abilities.Footnote 29 Huarte defended the notion that such extraordinary abilities could indeed be the result of a surfeit of the melancholic humor and thus the product of purely natural causation. Huarte asserted that when the brain’s temperature changed suddenly as a result of some melancholic disorder, it could lead to a dramatic transformation whereby even a fool might philosophize, versify, foretell the future, or speak Latin without having studied the language.Footnote 30 By way of example, Huarte recited a series of anecdotes, purportedly drawn from his personal experience, ranging from one in which a previously inarticulate man began to compose poetry in a fit of melancholy to another in which, famously, a rustic laborer acquired the ability to speak Latin with an eloquence rivaling that of Cicero addressing the Roman Senate.Footnote 31

Huarte’s analysis of melancholic genius bears a resemblance to those of Guainerio and Lemnius , although he does not mention either of them in his text. Like Guainerio and Lemnius, Huarte credited melancholy with the effect of liberating the rational soul to regain its original knowledge and capabilities.Footnote 32 According to Huarte, the abilities of melancholics to speak Latin without having studied it, or to foretell the future, were the result of adust melancholy , which was capable of creating a frenzied, hyper-excited state, very different from the typical symptoms of melancholic disorders. The capacity of the rustic laborer to speak fluent Latin was, in Huarte’s interpretation, a combination of this state of melancholic frenzy and Latin’s status as a supremely “rational” language which had a special consonance with the rational soul such that if the rational soul were to attain the proper temperament it would naturally hold forth in Latin.Footnote 33

This analysis depended on a particular theory of language in which words have a natural relationship to the things they represent.Footnote 34 Here he invoked the scriptural example of Adam giving names to the creatures of the earth,Footnote 35 and then went on to insist that if God presented the same things to a different man possessed of the same perfection and supernatural grace, that man would necessarily give them the same names as Adam did because both would have discerned the “nature of each thing.”Footnote 36 Because words bore the signs of their original inception, a rational soul sufficiently liberated from its carnal fetters could read these signs and discern their meaning. Thus, according to Huarte, if a man in a state of melancholic frenzy were to attain momentarily the same temperament as the inventor of the Latin language , he might simulate the same speech.

Huarte was not entirely consistent in his linguistic theorizing; elsewhere in the Examen he seemed to advocate an Aristotelian, conventionalist account of the development of language in which words functioned as arbitrary signifiers.Footnote 37 But when it came to the issue of xenoglossy , Huarte adopted the Platonic notion that words reflect the essences of things. In chapter eight of the Examen, for example, Huarte elaborated further on these issues, comparing the linguistic originalism of Plato with the conventionalism of Aristotle , ultimately asserting that “the opinion of Plato is closer to the truth.”Footnote 38

Huarte’s treatment of the extraordinary feats of the rústico labrador elicited numerous critiques, including Andrés Velásquez’s Libro de la melancolía , which was, as mentioned above, the first vernacular treatise on melancholy published in Europe.Footnote 39 Velásquez’s book, subtitled “whether a rustic in a state of frenzy or mania can speak Latin and philosophize without having previously studied,” vociferously denied the possibility of a natural explanation for xenoglossy . Velásquez was physician to the Andalucian town of Arcos de la Frontera and to the Duke of Arcos himself, and was educated in the same intellectual milieu as Huarte, having studied at Alcalá de Henares during the same years.Footnote 40 Velásquez considered his book not only a defense of Galenic orthodoxy in the face of Huarte’s deviations, but also, specifically, as an intervention in the debate over how to distinguish between demonic and natural causation in regard to extraordinary phenomena, a debate that was ever more pressing given the needs of exorcists to make such distinctions in their battle against what was perceived by some to be a rising tide of diabolism in post-Tridentine Spain .Footnote 41

Velásquez took issue with Huarte’s assertion that adust melancholy could be the source of extraordinary intellectual abilities. Whereas Huarte suggested—in similar fashion to Neoplatonists like Ficino —that the rational soul was capable of functioning independently of the body, of ascending like other disembodied spirits to ascertain certain “secrets of heaven ,”Footnote 42 Velásquez hewed to the hylomorphism of traditional scholasticism , insisting to the contrary that the rational soul is incapable of functioning in the absence of its physical “instruments,” and that as a result if these instruments were damaged by an excess of melancholy , the activity of the rational soul would likewise be curtailed. In Velásquez’s view, no substance that damages the sense faculties could give rise to an increased capability:

And so heightened abilities necessarily come from a good and perfect temperament; from a corrupt and damaged one we can expect only corrupt and damaged works. For this reason I consider it impossible within sound philosophy (although doctor Sant Juan uses up a great deal of paper in his Examen de ingenio (sic) providing examples to prove his case) for a melancholic to speak Latin without prior knowledge, or philosophize without having studied.Footnote 43

In the absence of any credible natural cause, Velásquez determined that preternatural phenomena such as xenoglossy or prophecy must be attributed to the machinations of demons , as the final sentence of his book emphatically declares: “My ultimate conclusion, in keeping with the opinions of the most erudite and worthy men, is that the aforementioned marvelous effects are not caused by the humors, or the influence of the stars, but rather by the work of demons.”Footnote 44

Another significant critique of the naturalistic account of xenoglossy was that of Pedro García Carrero , who dedicated a section of his Disputationes medicae super libros Galeni de locis affectis [Medical Disputations on Galen’s “On the Parts Affected by Disease”] (1605) to the relationship between demons and melancholy, and took aim specifically at the theories of Huarte and Lemnius.Footnote 45 Carrero took issue with the idea of innate knowledge that could be rediscovered by the rational soul. Instead, Carrero insisted that the mind is initially a tabula rasa upon which no knowledge other than that which is received through the senses can be inscribed.Footnote 46 Thus, in Carrero’s estimation, it would be impossible for the rústico labrador to regain prior knowledge of an unknown tongue through some form of Platonic reminisci, and absent this possibility, xenoglossy must be the product of a superior power, “either God , or good or bad angels.”Footnote 47 Carrero then advanced his critique a step further, disputing Huarte’s assertions concerning the nature of language by denying that words possess any intrinsic relationship to the things they signify and instead arguing that the meanings of words are conventions instituted by men.Footnote 48

The positions taken by Velásquez and García Carrero were part of what appears to have been something of a backlash against naturalistic accounts of melancholic genius and a renewed insistence on the powers of the devil .Footnote 49 Medical treatises by Francisco Vallés , Alonso Freylas , and Tomás Murillo y Velarde , for example, all took similarly critical stances toward claims of melancholic genius, and this emerging medical consensus spilled over into works by non-physicians.Footnote 50 Raphael de la Torre , for example, in his demonological tract, De religione et eius actibus [Of Religion and Its Acts] (1611), included a detailed refutation of Lemnius’s assertions concerning the ability of untutored melancholics to speak foreign tongues:

This disproves the delirious words of Levinus Lemnius , who in book 2 chapter 2 of Occultis naturae teaches that melancholics and frenetics, from the boiling of the humors and the vehement agitation of the spirits , are able to speak various languages, however little they knew of them previously. Impossible and incredible dogma!Footnote 51

This process of re-demonization was bolstered by the inclusion of xenoglossy as a key indicator of demonic possession in numerous manuals for exorcists, further reinforced by the Inquisition’s increasing reliance on xenoglossy as evidence of diabolism, and epitomized in the Rituale Romanum , issued in 1614 by Pope Paul V , in which speaking a previously unknown language was officially codified as one of the chief signs of demonic possession.Footnote 52

The debate over xenoglossy and the rústico labrador in early modern Spain is of intrinsic interest as an episode in the history of medicine and as an addition to the literature on melancholy in European history—but what broader conclusions might be drawn? First and foremost, we should resist the temptation to posit any neat teleologies that characterize the naturalism of thinkers like Huarte as a harbinger of modernity and the demonological explanations of thinkers like Velásquez and García Carerro as vestiges of medieval obscurantism. Huarte, for all his emphasis on natural causation, did not deny the possibility of demonically inspired xenoglossy .Footnote 53 And Velásquez and García Carerro , in turn, were no less committed to natural therapies in treating melancholic illnesses, regardless of whether they were caused or exploited by demons . In the case of García Carrero, because he held that the devil operated via proximate causes found in nature , it was no contradiction to suppose that medical means could be effective against diseases brought about by demonic manipulation, even if in the overarching causal schema material causes could never take precedence over spiritual ones.Footnote 54 In the case of Velásquez, he recognized demonic intervention only in the facilitation of the extraordinary intellectual feats of melancholics, not in the generation of the disease, which meant that the physician could rely on natural therapies while deferring to priests and exorcists when it came to the spiritual dimension.Footnote 55 Thus, we are not faced with a zero-sum game in which melancholy serves as a naturalistic explanation that necessarily supplants a spiritual, demonological one.Footnote 56

Another reminder of the problems inherent in sorting early modern thinkers into “progressive” and “retrograde” camps is the debate over the origins of language referenced above. Huarte has often been identified as a forerunner of modern-day linguists who posit an arbitrary relationship between signifier and signified.Footnote 57 But as we have seen, Huarte was far from consistent in his theorizing about language, and when it came to xenoglossy he was still firmly wedded to the idea that words bore an intrinsic relationship to things. It was, in fact, Huarte’s opponents who hewed more rigorously to the conventionalist theory of language. As it happens, this fits with observations made by Stuart Clark concerning competing theories of language during the period.Footnote 58 Clark has noted that representational theories of language went hand in hand with the philosophical realism demanded by the new science , and it was, counterintuitively, demonologists who spearheaded the campaign to conceptualize language as purely conventional rather than as a system of natural and necessary links between words and things. The spells and incantations that permeated early modern popular culture depended upon the magical power of words to influence persons and objects, but early modern demonology was predicated on the assumption that these practices were demonic, and thus “superstitious,” precisely because there was no causal efficacy between words and things. As a result, anti-superstition writers often ended up on the same side of the linguistic divide as Enlightenment heroes such as John Locke , although for very different reasons. With this in mind, it makes sense that García Carrero championed a demonological interpretation and at the same time insisted on the conventionality of language, while his adversary, Huarte, argued for a naturalistic explanation for xenoglossy , but was still willing to entertain the soon-to-be-outdated theory of linguistic originalism.Footnote 59

Finally, on a broader level, it may be tempting to view the controversy over whether to categorize the preternatural locutions of the rústico labrador as melancholic genius or as superstitious diabolism through the lens of “disenchantment” used by Max Weber to examine what he saw as the desacralization of the natural world and human society by Western science and bureaucratic rationalization.Footnote 60 In this framework, melancholy becomes a naturalizing vehicle for supplanting the agency of spirits . Indeed, Euan Cameron , in his book Enchanted Europe : Superstition, Reason, and Religion 1250–1750, presents melancholy as an alternative to supernatural explanations in precisely this way, writing in a section on Robert Burton’s Anatomy of Melancholy that

The subject of melancholy would become enormously important in the controversies of the seventeenth century: it was increasingly argued that ‘melancholy,’ meaning a common and rather diverse and widely diffused mental disorder, might explain many of the visions and other supposedly ‘supernatural’ experiences reported by the common people.Footnote 61

As Cameron’s title suggests, he makes use of the framework of disenchantment, focusing on seventeenth-century England where, in his account, rifts within the discourse on superstition combined with investigations into the etiology of melancholy , scientific naturalism, and new alternatives to scholastic-Aristotelian metaphysics to cast doubt on the workings of the traditional spirit world. In Cameron’s telling, the distinctive literary-philosophical milieu of Restoration England was ultimately instrumental in eroding the reigning “demonological consensus,” thus paving the way for wholesale skepticism concerning the existence of spirits .Footnote 62

There is no denying the influence of this late-seventeenth-century English intellectual milieu on European ideas about religion and natural philosophy, but one of the dangers of measuring historical change on a timeline of disenchantment is that it tends to elide the epistemological diversity of pre-modern societies. As Richard Jenkins has pointed out, it is “questionable whether the ‘enchanted world’ was ever as unified or homogeneous in its cosmology and beliefs as Weber’s argument seems to presume.”Footnote 63 Jenkins goes on to assert that the pre-modern European world was, in fact, always “epistemologically fragmented,” rife with “skepticism , heresy , and pluralism.”Footnote 64 Within the framework of disenchantment, Spain is typically relegated to the role of pre-modern, enchanted Other, and it thus seems telling that even in a treatment as wide ranging as Cameron’s , Spain is largely absent—and when it does appear it is presented as a bastion of traditional scholastic thought, incapable of the sort of cultural innovation we see in England . This omission is especially glaring, given the fact that the Iberian peninsula contributed a great deal to discourses on superstition and melancholy.Footnote 65

Cameron argues that a unique set of factors converged in late-seventeenth-century England to destabilize the metaphysical foundations of “enchanted Europe.” But could these foundations also have been weakened elsewhere and otherwise? Cameron does concede the potential of Neoplatonism as an alternative to scholastic-Aristotelian metaphysics, but dismisses this possibility because in his estimation Neoplatonists were “cultural elitists who had nothing to gain by intervening in the theological analysis of folkloric practices.”Footnote 66 As we have seen, however, in Spain there existed a strong current of Neoplatonism , which interacted with neo-Galenism, Hippocratism, and traditional scholastic-Aristotelianism to produce a vigorous debate over the nature of melancholic genius, a debate that did indeed intervene in the theological analysis of popular religious practices as a topic in anti-superstition treatises, manuals for exorcists, medical texts , and Inquisition trials. This debate generated a good deal of innovative natural philosophical speculation and medical theorizing based on case studies of actual peasants, penitents, and patients.Footnote 67

But even if we accept the possibility of a greater latitude for intellectual experimentation in sixteenth-century Spain , what are we to make of the reaction against naturalistic accounts of melancholic genius? I would suggest that even in the wake of this backlash, we should not assume a return to a wholesale embrace of traditional demonology or a consensus about the interactions of spirits and humans. To be sure, in post-Tridentine Spain the devil loomed large in the collective imagination, but there was ample room for skepticism , dissent, and even ridicule. Rather than seeing the backlash as part of a definitive ideological crackdown on the part of a militant Counter-Reformation , it should be viewed as part of a dialectical process in which the champions of demonological interpretations often overplayed their hand, setting the stage for a new round of skeptical challenges.Footnote 68

In perhaps the most prominent example of this dialectic, we have the Spanish Inquisition’s skepticism with regard to the prosecution of witches, which was epitomized by Inquisitor Alonso de Salazar y Frías’s dispatch to the Supreme Council of the Inquisition in response to the outbreak of witch hunting in the Basque country during the early seventeenth century.Footnote 69 While Salazar did not deny the existence of demons or contest their agency in the natural order, he doubted that these demonic interventions happened frequently, and he derided the idea that they should form the basis for witchcraft prosecutions. For Salazar, most of the reported activities of demons and witches could be dismissed as rumor and hearsay. As he famously put it, “There were neither witches nor bewitched until they were talked and written about.”Footnote 70 Salazar may still have been living in an “enchanted” world, but it was one that was increasingly being brought under the strictures of bureaucratic rationalization and one in which the spirit world was increasingly adjudicated according to codified legal procedures.

A lesser-known episode provides another example of the diversity of opinion surrounding demonology in baroque Spain . In the seventeenth century, there was no shortage of warnings about the growing power and ubiquity of the devil , and out of this milieu arose a campaign to imbue the Habsburg kings of Spain with the power of exorcism . Although other European monarchies had traditions of royal thaumaturgy , Spain did not. Yet by mid-century, there were a number of writers insisting that Spanish kings could, and should, do battle with the minions of Satan .Footnote 71 In response to these extravagant demonological claims, we do not see a consensus marching in lockstep, but rather a protracted debate that culminated in a three-day forum held in September of 1654 at the royal court in which the matter was discussed by university professors, natural philosophers, and physicians—with Philip IV himself in attendance.

Despite the obvious propaganda benefits of establishing a tradition of charismatic kingship, the campaign backfired. In part this was due to skepticism concerning the natural philosophical rationale for these extravagant demonological claims. Gaspar Caldera de Heredia , for example, took issue with the need for any God-given charisma when it came to exorcism , arguing instead, in a similar fashion to Velásquez and García Carrero , that demonic possession was achieved through proximate causes, and thus might be addressed through these same causes:

[I]f he [i.e., the devil ] works via some instrument, it will be possible to expel and overcome him through purely physical, natural means. For example, if he avails himself of melancholy as an instrument with which to work … this can be evacuated, or tempered, by the [medical] art. And by getting rid of the instrument the demon can be expelled as well, since he has relied on such a fragile instrument.Footnote 72

Thus, the mere touch of the Spanish kings, absent the infusion of divine grace, would not be capable of altering the humors in such a way as to ameliorate a demonic possession.

Other contemporary observers were less concerned with natural philosophical abstractions and confronted the suggestion of royal exorcism with skeptical derision, as in the case of Jerónimo de Barrionuevo , who ridiculed one of the participants in the debate, informing his readers that

[a] doctor from Andalucia has argued in a public debate held in the monastery of la Encarnación that in the same manner as the kings of France have the gift of healing scrofula, the kings of Spain are able to cure demoniacs. This is not a joke. His views have been published and as soon as I get my hands on them I will make them available to you.Footnote 73

The failure of this campaign to institutionalize royal charisma (to put it in Weberian terms) paradoxically set the stage for a more disenchanted model of authority in which subjects were bound to their sovereign by purely political imperatives rather than as participants in an elaborate cosmic hierarchy.Footnote 74

Returning to the case of Antonio de Bolívar , where this essay began, we see evidence of a similar skepticism on the part of his inquisitors concerning claims of diabolism. They dismissed out of hand the reports of demonically inspired xenoglossy , insisting instead that the “rustic person” under Bolívar’s spiritual direction was a fraud, and that Bolívar had conspired to fake divine raptures and revelations in order to enrich himself by collecting alms, and that the purported possessions were merely attempts to “elude the judgment and impede the functioning of the Holy Office by claiming that all the things they have said and done were not their own words and actions, but rather those of the devil .”Footnote 75

In the eighteenth century we find still more skepticism directed at the purported feats of the rústico labrador in the work of the Spanish philosophe Benito Jerónimo Feijóo y Montenegro . Feijóo entirely sidesteps the controversy over natural versus demonic causation and dismisses reports of xenoglossy as inevitably feigned. Feijóo relates a case of a peasant woman from Oviedo who claimed to be possessed and was reported to have spoken Latin without ever having studied it. In an effort to debunk her claims, Feijóo adopted an experimental approach, staging a mock exorcism in which he spoke lines from Virgil and Ovid instead of the standard exorcisms. The woman, as Feijóo had predicted, responded with the typical exaggerated gestures that would have been elicited by the ecclesiastical Latin of the exorcism rite. As further proof of her fraud, Feijóo noted that she could follow his commands in Spanish but was at a loss when confronted with any Latin phrases that went beyond the stock formulations.Footnote 76

By the eighteenth century both the Protestant and Catholic camps seem to have arrived at a new consensus on the structure of the causal taxonomy outlined at the beginning of this chapter. This amounted to a renegotiation of what could and could not happen in the visible and invisible worlds, a renegotiation that Fabián Alejandro Campagne has referred to as a new “Christian sense-of-the-impossible.”Footnote 77 Campagne’s assertion is a response to Lucien Febvre’s claim that early modern Europeans possessed no “sense-of-the-impossible,” because for them “there was normal and constant communication between the natural and the supernatural.”Footnote 78 According to Febvre, “Their world was a fluid one where nothing was strictly defined, where entities lost their boundaries, and, in the twinkling of an eye, without causing much protest, change shape, appearance, size, even ‘kingdom,’ as we would say.”Footnote 79 As we have seen, however, this was never the case for Protestant or Catholic theologians; there were always strict parameters determining what spirits could and could not do. But as we move into the eighteenth century, we begin to enter a new regime in which supernatural and preternatural interventions, although theoretically possible, became the rarest of occurrences. For Cameron , this development was driven by metaphysical debates prosecuted by English Protestants. Campagne, on the other hand, offers an alternative trajectory in which Spanish thinkers, rather than merely reacting to the arguments of Protestants, played an equally significant role. In Spain it fell to thinkers such as Feijóo to articulate the new, fully formed Christian sense-of-the-impossible, as when he asserted, echoing Salazar, that “there do not appear to be any possessed people except where there are gullible people who say there are.”Footnote 80

The career of the rústico labrador is a good example of the many ways in which knowing demons and spirits related to other kinds of knowing in early modern Europe. It highlights the wide range of theological and natural philosophical debates concerning the nature and role of spirits within the Christian cosmos and how they interacted with both the physical world and the human psyche. The Spanish interventions in these debates complicate familiar narratives and can potentially help us avoid hasty idealizations of complex historical realities, which is a danger when invoking the framework of disenchantment. As Egil Asprem has recently warned, when we identify certain intellectual developments as causal agents of disenchantment, “there is a tendency to prioritise a specific set of cultural impulses—above all Protestant theology and Kantian philosophy—when determining normativity and deviance in Western intellectual history.”Footnote 81 With this in mind, the contributions of Spanish thinkers to polemics surrounding melancholic genius in early modern Europe take on a heightened significance, revealing an epistemological pluralism that only comes into focus when we broaden our purview beyond the norms of canonical Western intellectual history.