Historicising stress: anguish and insomnia in the middle ages

Abstract

While the concept of ‘stress' in the modern sense is a twentieth-century innovation, many of the symptoms we associate with the modern condition appear in historical materials going back many centuries. But how did premodern people understand and experience these symptoms and their relation to sleep? This study focuses on the rich materials from the central middle ages in Western Europe, a period during which understandings of the body, mind, emotions and sleep were radically different from the present. It analyses two examples, nightmares and insomnia, disease categories which illustrate medieval views of the impact of worries and anguish on sleep. Medical and other sources identified a number of ways in which the mind and body interacted with one another in complex ways which disrupted the humoral and mental balance of the individual.

1. Introduction

How many thousand of my poorest subjects

Are at this hour asleep! O sleep, O gentle sleep,

Nature's soft nurse, how have I frighted thee,

That thou no more wilt weigh my eyelids down

And steep my senses in forgetfulness?

Why rather, sleep, liest thou in smoky cribs,

Upon uneasy pallets stretching thee

And hushed with buzzing night-flies to thy slumber,

Than in the perfumed chambers of the great,

Under the canopies of costly state,

And lull'd with sound of sweetest melody?

O thou dull god, why liest thou with the vile

In loathsome beds and leavest the kingly couch

A watch-case or a common ‘larum bell? ….

Canst thou, O partial sleep, give thy repose

To the wet sea-boy in an hour so rude,

And, in the calmest and most stillest night,

With all appliances and means to boot,

Deny it to a king? Then, happy low, lie down.

Uneasy lies the head that wears a crown.

With these words (Henry IV Part 2, act 3, scene 1), Shakespeare gave voice to King Henry IV's troubled thoughts as he contemplated his inability to sleep [1]. The passage contrasts the apparent ease with which his poorer subjects could slumber despite their squalid surroundings with the difficulty in sleeping which he encountered inside his regal bedchamber. The argument centres on the claim that the affairs of state weighed heavily on a king, leading to his disturbed sleep, while the common people had no serious worries and thus slept soundly. Shakespeare's contrast between kings and commoners does not stand up to historical scrutiny; we know that worry and sleeplessness affected people across the social spectrum in the premodern world, as they do today [2]. However, in the speech, an inverse relationship between physical space and mental state––an uneasy pallet but sound sleep versus a kingly couch but uneasy mind––allowed the Bard to emphasize the old king's preoccupation with rebellions and other political perils which threatened both his rule and his sleep patterns.

It is the last concern which will be the focus of what follows: to what extent did premodern society conceive of a relation between worry and rest? In the modern world, we are aware of the often negative associations between stress and sleep, but which concerns were articulated in earlier periods? This study argues that there is, in fact, evidence of considerable premodern interest in and concern over issues associated with the category we call ‘stress'. Symptoms very similar to the diagnostic criteria used in modern psychiatry appear in medical and other sources of premodern Europe. This study considers the rich materials from a period long before Shakespeare wrote his plays and turns our attention not to the late Elizabethan world of the 1590s but four hundred years earlier, when during the central middle ages—particularly the twelfth and thirteenth centuries— issues relating to anxiety and sleep disturbance were discussed with surprising regularity.

There are several initial observations and impediments to consider before we continue. First and most importantly, there is no direct premodern parallel to the concept of stress, in the modern usage of the term. Historians of medicine worry considerably about the danger of imposing modern medical and psychological categories on the past, a process often known as retrospective diagnosis. In this instance, we will encounter psychological and physiological experiences which mirror some of the symptoms of the modern category of stress. However, there is no evidence that anything close to ‘stress' existed as an independent, recognizable category in medical discourse before the twentieth century. Instead, we find individual somatic and mental phenomena which may be comparable to some aspects of what we now call stress, as well as occasional references to overwhelming situations of a psychological and physical nature.

The concept of stress in the modern medical sense has a complex history, arising largely out of the work of Hans Selye from the 1920s onward, as he mapped out how the body responded to external factors through the nervous system, as seen in his arguments for a general adaptation syndrome. Selye's endocrinological work itself derived from the studies by the physiologists Claude Bernard and Walter Cannon on the body's attempt to maintain a systemic balance despite various threats. Cannon argued that the physiological systems of all animals attempt to maintain a steady state (derived in part from Bernard's notion of a milieu intérieur) or what he called homoeostasis; he also coined the phrase ‘fight or flight' to describe the nervous system's response to external threats. The concept of stress was taken up by psychiatrists and psychologists in the 1950s, as they identified the ways emotional and physiological forms of stress had an impact on mental health. The term entered into more popular materials even more recently, from the 1970s onward, and its ubiquity in modern medical and popular literature amply demonstrates the remarkable success which the term has achieved [3–5].

Stress has become one of the most emblematic conditions of the modern world, but what, if any, kinds of parallels existed before the homoeostatic claims of Cannon or the endocrinological research of Selye? The basic language of stress is borrowed from engineering, in which the tensions, pressure and stresses of architecture and machinery have been applied to the workings of the body and mind. The nineteenth-century fascination with industrial equipment such as pressure pumps is to some extent reflected in the experimental physiology of figures like Angelo Mosso, who studied the patterns of fatigue in the human body in the 1880s [6].

The idea of the body as a machine seems ultimately to derive from the mechanical philosophy of the early modern period. In the 1630s and 1640s, natural philosophers René Descartes and Pierre Gassendi argued that the human body was built of corpuscles or atoms and worked like a clock or automaton, with their gears and wheels. Nevertheless, mechanical philosophy also recognized an inherent dualism specific to humans, between the material body and the immaterial mind, which Descartes famously linked in the brain via the pineal gland in The Passions of the Soul (1649). By the later seventeenth century, Thomas Willis applied the mechanistic and corpuscular theory to the brain, the nerves and their pathologies in the 1660s. During the eighteenth century, Willis's ideas led to the rise of a number of fashionable diseases of the nerves, as seen most famously in George Cheyne's The English Malady (1733). For Cheyne, these nervous conditions, such as hysteria or hypochondria, were reframed or newly identified as arising from the quality of the diseased individual's nerves, particularly if they were too weak or loose. While stress as a concept does not appear in the eighteenth-century medical literature, Cheyne and others argued that inherent dispositions and some external factors could alter the quality of the nerves, leading to various nervous pathologies [7,8].

Yet, before the rise of the early modern mechanistic and nervous models, there existed a radically different concept of both physiology and pathology in the Western medical tradition, firmly fixed in the Hippocratic–Galenic humoral model of the body. This understanding was based not in the status of the nerves but in the balance of humours and qualities in the body. That is, the four humours (blood, phlegm, red or yellow bile and black bile) and the four qualities (hot, cold, wet and dry) were the essential constituents of the body and determined each individual's state of health or illness. Following the ancient Greek ideal of moderation, a proper balance of the humours and qualities constituted health while any imbalance of humours or qualities would indicate a diseased body [9,10; 11 (ch. 10)].

The purpose of premodern medicine was, as a consequence, built around the desire to regulate the body by either maintaining humoral balance or restoring the body to equilibrium, if it had become unbalanced and consequently diseased. In this sense, both the curative and preventative aspects of Galenic medicine had the same goal, of restoring balance and thus health. While many pathological conditions were thought to arise internally out of an excessive preponderance of one humour or quality, there were other factors which received particular emphasis in the preventative literature. From late antiquity onward, six phenomena were singled out as having an important impact on health. They became known as the six non-naturals, so-called because they were not intrinsic to the individual's constitution (the ‘natural' state of the individual) but could change, or be changed, and thus affect health. They consisted of both internal and external phenomena: the physical environment in which one lived, especially the air; food and drink; evacuations and retentions; activity and rest; sleep and waking; and the accidents of the soul, largely what we consider (following Descartes' invention of the term) the emotions [12,13]. There developed from this a literature of preventative medicine, the regimens of health, focusing on how to control each of the non-naturals and allow the person to remain healthy. In what follows we shall focus primarily on the final two categories: sleeping and waking, as well as the emotions, and their connections with worry and anguish.

2. Sources and terminology

While no overarching category of stress existed in the medieval (and more broadly the premodern) world, there was a keen awareness of the impact of what we could call psychological concerns on the body, and vice versa. The issue of which of the two—mind or body, psyche or soma—took priority over the other was, as we shall see, complex and remained unresolved. Before Descartes' strict divide between body and mind, the boundaries between the two were permeable, leading to conditions that could be understood as psychosomatic and somatopsychic. The sources we shall focus on also acknowledge the complex relationship between sleep and pathologies of the body and mind. A study of the medical terminology of the period reveals the variety of ways in which medieval physicians understood the intertwining mental and corporeal implications of phenomena such as worry and anguish.

Before turning to the terms, it is important to understand what types of sources are available to us from a distance of eight centuries. This study focuses on the twelfth and thirteenth centuries because this was a pivotal period in the history of medicine, as Western Europe rediscovered ancient Greek medical learning via the Arabic-speaking world, from the late eleventh century onward. The rise of universities in Italy, France and England in the late twelfth century quickly created an intellectual space for medicine, alongside law and theology, to thrive and to expand the authority of learned physicians [14,15]. This study brings together not only the early Latin translations of Greco-Arabic materials, particularly the influential work of Ibn Sina (Avicenna) and al-Majusi (Haly Abbas), but also the most influential medical writings composed in the West during the thirteenth century, by figures such as the Montpellier-based physicians Arnald of Villanova and Bernard of Gordon [16–19]. All of these sources explicitly view the body from a Galenic framework, following and elaborating upon the Greek humoral model of physiology and disease. To complement the medical writings, a number of natural philosophers such as Albert the Great (Albertus Magnus, d. 1284, Dominican friar and bishop of Regensburg, who wrote extensively on many topics, from theology and metaphysics to zoology and mineralogy) also discussed the concepts of anguish, worry and sleep from a humoral perspective [20].

The medical sources provide insight into the learned tradition and its theories of mind and body, but not necessarily into the experiences of those who endured worries and sleep disturbances. We can in part redress this imbalance by turning to a very different type of source, which purported to document the physical and psychological suffering of specific individuals: the medieval miracle tale. Stories of miraculous healing appear in the earliest Christian writings: a large percentage of the Gospel accounts of Jesus's life consists of his miraculous cures of the ill, a power which his apostles and other holy figures perpetuated after his death. By the twelfth century, large collections of miracle stories appeared in England and northern Europe [21–23] often focusing on recent stories of suffering by individuals from different walks of life, from royalty to the peasantry. Social historians have used these sources, with caution, to give some sense of the patient's point of view, in contrast with the more traditional medical sources. The tales do not provide unmediated access to the suffering experienced by people in the central middle ages: they were recorded not by the sufferers themselves, but by learned religious figures for a specific purpose, to demonstrate the spiritual power of a particular saint [24,25]. Nevertheless, they provide an important perspective which complements the medical texts and provides a fuller picture of the psychological and physical ailments which medieval people could endure.

Despite the differences between the sources, physician-centred versus patient-centred, the language they use to describe the afflictions in question are often similar. Terms such as angustia (anguish), sollicitudo, curae (both meaning worries or cares), perturbo (to disturb) or inquieto (to unsettle or disquiet) appear in both medical and miracle literatures. The first term, angustia, illustrates the difficulties concerning the relation between body and mind, as it indicated both bodily and mental difficulties. Etymologically, the term derives from a root word referring to ‘narrowing' or ‘suffocating', and is related to the more technical term anxietas, used primarily in the medical material to indicate psychological concerns. Angustia referred to bodily more often than mental manifestations, and specifically was associated with physical pain, although it could have metaphoric implications of a more psychological nature. Among the miracles of Saint Foy at Conques, collected in the eleventh century, we encounter examples of the blurring between mental and corporeal states associated with anguish and anxiety. A reference to a youth being ‘anxious and full of intolerable worry' or a man with a sword wound sleeping ‘through the anguish of sorrow and sadness' coexist in the same text with references to another youth ‘anxious with pain’ [26 (1.21, 2.7, 4.17)].

By contrast, terms like sollicitudo or curae more specifically indicated a state of mental distress, generally referring to concerns which weighed on a person's mind [27 (6.2, p. 263); 24 (1.21)]. The ideas of perturbation (perturbo, turbatus) and disquietude could have both somatic and psychic origins and consequences, both the body and mind being described as potentially experiencing disturbance, of the humours or of the accidents of the soul (emotions). Underlying the term inquieto, to disturb or disquiet, was its opposition to the idea of rest (quies, requies, and the related verb requiesco), with its implications of both physical rest (including sleep) and mental calm [28 (ch. 9, p. 432); 25 (1.44, p. 45)].

It is worth noting here the earliest use and meaning of the word ‘stress' in English, further illustrating the complex blurring of physical and psychological concerns across the centuries of the term's history. The earliest English-language usage of the word is attested at exactly the end of the period with which we are here concerned. Begun in 1303, a devotional treatise by Robert Manning (Robert of Brunne) called Handlyng Synne refers several times to the phrase ‘yn hard stres'. The word derives from the Latin strictum, ultimately from the verb stringo, to tighten or compress (compare with the etymology of angustia, above). In this text, the English term is an abbreviation of ‘distress' and it seems primarily (but perhaps not exclusively) to refer to physical discomfort or adversity: in this instance, the difficulties faced by the Israelites wandering in the wilderness after leaving Egypt [29 (line 5003); 30 (entry for ‘stress')].

3. Sleep, the mind and the origin of dreams

Premodern medical views of sleep differ considerably from our own assumptions about the state of slumber. Through the eighteenth century, the most influential theorist of sleep remained Aristotle (384–322 BC), who wrote three short treatises on the subject and discussed it extensively throughout his natural philosophical and psychological works on animals and on the soul. He argued that there was a dichotomy between the waking and sleeping states, the latter being seen as the ‘privation of waking' and defined by an absence of sensation and external bodily movement [31]. Despite this negative definition (that is, identifying what sleep was not, rather than what it was), Aristotle also noted that sleep was beneficial and necessary in its ability to restore the body's vigour after each day's activities. In particular, sleep played an essential role in the proper digestion of food, which itself was necessary for the production of blood. Before William Harvey argued for the circulation of blood in the early seventeenth century, the predominant Galenic medical view argued for the daily or, more accurately, nightly production of blood out of the food consumed while awake. During sleep, blood was produced in the liver, whence it moved to the heart and began a purely centrifugal movement to the body's extremities, during which process it was consumed each day. The sleeping body's external immobility and frigidity allowed the heat to move inward in order to transform food into blood through a process of internal warming or ‘concoction' [31,32]. In this physiological model, sleep was essential to the restoration of the body and its proper functioning while awake.

Such arguments may have explained the actions of the sleeping body, but what did they say about the slumbering mind? Following Platonic and Galenic concepts of the mind, there developed a theory of cognition which predominated from the late Roman Empire to the seventeenth century. In this view, the brain consisted of three regions—called cells or ventricles—which played distinct roles in the cognitive process. All sensory perceptions were received by the five senses and then gathered together by what was called the common sense at the front of the brain. In the same front cell of the brain lay the imagination or phantasy, which turned sense perceptions into sense impressions, forms or shapes which were temporarily retained as the mind sought to comprehend the sensations. The second cell housed the rational powers, which could interpret and make judgements about the information received by the front cell. Finally, the third cell, at the back of the head, was reserved for the memory, which allowed for both retention and recollection of knowledge. Such was the primary model for understanding how the waking mind worked and where in the brain each of the cognitive functions was located. In strong contrast, the sleeping brain was thought to have a much reduced functioning. In sleep, the five senses were largely shut off, as were the rational faculties and the memory. The only part of the brain which remained fully active during sleep was the imagination [33–35].

Medieval dream theorists often distinguished a hierarchy of dreams, from the highest types of prophetic visions directly inspired by God and his emissaries down to the lowest types of dreams arising out of the individual's preoccupations and often bodily desires. It is this last type which was most influenced by the dreamer's imagination, since it was based in the individual's bodily and mental preoccupations during the waking state. Phantasms appeared in the imagination based on the forms or shapes which had been imprinted on the imagination during the day and resurfaced in the individual's dreamscape [36,37]. Physicians sometimes associated the imagination with mental distress: the Montpellier physician Bernard of Gordon noted that because even in sleep, ‘the imagination never ceases, but is in constant motion, thus we are in continual torment (cruciatus)' [19]. Bernard does not elaborate on the nature of this torment for the waking or sleeping person, but he and others noted that the imagination formed the basis of dream content.

The more theoretically orientated medical and natural philosophical materials discussed the role of worries or anxieties in the production of dreams. Medieval natural philosophers associated worries with the sixth non-natural, the accidents or passions of the soul (the emotions), and connected cares with fear and other emotional states which could affect the body in a negative way. Albert the Great and others noted that various types of worries could affect sleep, including solicitude over one's family and possessions. He notes that ‘cares and worries accompany dreams' and more emphatically states that ‘man greatly dreams of those things about which he is most worried and to which his thoughts most often turn' [20 (Summa de creaturis 4.52)] The phantasms produced by the imagination in sleep may have been illusory, but they produced psychological reactions, some (as seen below) very dramatic. For Albert, worries and desires of the waking state had led to the appearance of these images in dreams, which themselves led to further worries both during sleep and afterwards. Sleep could produce its own anxieties, as well as reflect those of the waking state.

Medieval writers noted that worries could influence sleep in various ways, but we shall focus on two: the impact of daily concerns on dream content, especially in nightmares, and their impact on the ability to get to sleep, via the disease category of insomnia. The sources for each of these are particularly rich and raise important issues over the ways in which mental and physical symptoms were understood and dealt with in the diagnosis and treatment of diseases.

4. Nightmares, the incubus and anguish

We have seen that the concerns of the waking state could resurface in sleep and haunt the dreamer. One dramatic example of anguish in sleep stands out from the rest: the disease category known as the incubus, or the nightmare properly speaking. From the Roman era onward, physicians recognized the existence of a condition, called ephialtes in Greek and incubus in Latin, which highlighted the psychological and physical trauma which could arise in sleep. In this condition, which bears considerable similarities to what we call sleep paralysis, sufferers felt a pressure on their chest and believed that an external force—a demon, animal or even old woman—was crushing them. In strong contrast, physicians argued for a less external and less supernatural aetiology, claiming instead that the individual had simply eaten or drunk too much, leading to indigestion, which produced the sensation of heaviness [38,39]. Medical writers of the thirteenth century were particularly keen to explain why the patient wrongly imagined that he or she was under assault by something outside the body. By definition, the sleeper had no ability to think rationally, but nevertheless sought an explanation for the sudden, disturbing sensation of heaviness he or she felt. Physicians argued that the imagination, freed from any association with rational thought, promptly interpreted the sensations as an (ultimately fictional) external attack [37; 18 (290–291); 19 (74rb)]. While the sensations were real, physicians argued, the incubus itself was a fiction produced by the mind in sleep.

This contrast between interpretations by patient and physician appears in various contexts. In one tale of miraculous healing attributed to Thomas Becket, collected at the end of the twelfth century, we hear of a knight named Stephen of Hoyland who had suffered for thirty years from night terrors, which he believed were caused by a demon crushing or suffocating him. He consulted several physicians, who identified his condition as a disease (ephialtes) rather than a demonic attack. But he rejected their diagnosis and, in the strongest possible terms, remained convinced of the external and supernatural nature of his night-time torment. The author of the miracle story, Benedict of Peterborough, describes Stephen's experience as a particularly painful form of angustia: Stephen cried out in his sleep and begged his servants to wake him immediately, to sit him upright, and even to pull his hair in order to rouse him and prevent the demon from killing him [27]. Rachel Koopmans has recently identified a depiction of Stephen's story in the medieval stained glass of Canterbury Cathedral, produced not long after the miracle was written down. In the window, Stephen lies on his side in bed, while a person (presumably one of the servants) leans over him, perhaps trying to awaken him, while three demons crowd around the bed with menacing faces [40]. The fear that the incubus would return each night brought a sense of dread which compounded the physical suffering experienced by Stephen and others like him. The anguish here is both psychological and physical: it is manifested as extreme fear (and the recurring expectation of fear) as well as anguish (angustia) in its physical, etymological sense of constricting, the sensation of being crushed, possibly to death. Medical writers often noted the patient's tendency to believe his or her life was endangered. One medical text explained that the condition was sometimes known as ‘the strangler' (strangulator), alluding to the imagined lethal consequences which sufferers might attribute to it [41 (ch. 2, fol. 19va)]. The fear of death in sleep dominated the discussion of the incubus.

The fear of being attacked in one's sleep by menacing supernatural creatures appears sporadically among the conditions which drove sufferers to saints' shrines. A lengthy narrative of miraculous intervention by Saint Ithamar, seventh-century bishop of Rochester and first Saxon-born bishop in the British Isles, recounts another case of fear induced by recurring oneiric visitations by a whole host of demons who tormented a monk as he slept [28 (ch. 9, p. 432)]. Like Stephen of Hoyland, this man experienced these nightly assaults so frequently that he began to dread falling asleep. These were more nightmarish visions than specifically attacks by an incubus, but they reflect a larger recognition that the content of one's dreams could cause problems, not simply producing fear over the course of the dream but also leading to disturbance of sleep itself, demonstrated by difficulties with both its onset and its continuity.

The cures in the medical sources differ almost entirely from poor Stephen's solution. In only one source, the eleventh-century Passionarius of the Salernitan physician Gariopontus, does a physician suggest waking the sufferer from sleep by violent means, in this case, by pulling the hair, just as Stephen had requested of his servants [42 (ch. 17)]. Stephen was convinced that he would be killed in his sleep, if he continued to lie prone on his bed, hence his requests that his servants awaken him and raise him from his recumbent position. By contrast, the medical remedies generally sought to do the opposite by putting the patient at ease and to sleep, through a variety of largely narcotic medicines [37; 19 (fol. 74va)].

The story of Stephen of Hoyland's nightly torment provides a clear illustration of a conflict between the patient's and the physician's points of view. Yet despite their differences, both perspectives acknowledged the physical as well as the psychological aspects of the phenomenon. In particular, they seemed to agree on the causal relation between body and mind: the physical phenomenon preceded—and thus elicited—an emotional response: literal angustia (narrowing, a sensation of being strangled or crushed) led to mental angustia (anguish).

5. Insomnia and anxiety

Probably the most common association between anxiety and sleep lay (and perhaps still lies) in the recognition that the former could impede the latter. Like stress, insomnia is often seen as a disease of modernity, and an industry devoted to sleep regimens has arisen around it. But as the quote from Henry IV indicates, difficulty in sleeping has a long history and is attested in the earliest literature, from Gilgamesh onward [43]. The medieval medical tradition paid considerable attention to the inability to sleep, which was most often encompassed by the term vigiliae. The word technically meant not sleeplessness but a type of (pathological) wakefulness. In fact, the term could refer to at least three different types of waking states. In the singular, vigilia indicated the normal, healthy state of being awake in contrast with the state of sleep (Aristotle's treatise on sleep is, in its Latin translation, known as De somno et vigilia, On sleep and wakefulness). Secondly, it could also denote a voluntary wakefulness in the sense which we still use, of a night-time vigil, a sleepless night spent in prayer or on guard. We have already encountered this meaning in Henry IV's reference to a ‘watch-case', the place where a night watchman would stand guard; the words ‘waking' and ‘watching' derive from the same etymological root, and were at times interchangeable [30 (entry for ‘wake')]. And finally vigiliae, the plural of the term, could signify an involuntary wakefulness, the pathological state with which we are concerned here [16 (3.1.4.4)]. While the term vigiliae remained the most common term to denote sleeplessness, from the eleventh century onward, the abstract noun insomneitas was used increasingly often in the medical literature to describe the pathological state of sleeplessness [17].

Medieval medical literature identified the accidents of the soul as a major cause of involuntary wakefulness. Bernard of Gordon, the renowned physician at the University of Montpellier around 1300, noted that anger, sadness, worry and related sensations were often to blame for sleeplessness, alongside other, more physical causes including excessive food, light, pain or fever. Following Aristotelian terminology, all of these activities fell under the category of movements, which included the emotional, intellectual and physical. Too much study and overly strong emotions produced excessive movement of the brain, an overstimulation which was identified as an important cause of insomnia [16 (2.18)]. The miracle stories corroborate the association between mental states and insomnia: a young girl suffered sleeplessly through the night with fearful suicidal thoughts until Becket intervened [27 (3.3, p. 285); 44 (6.2, p. 263)], while an insane woman remained awake for days fearing the devil, until she arrived at the tomb of St William of Norwich [45 (6.6, p. 226)].

Yet the relation between anxiety and insomnia was recognized to be complex, as seen in two very revealing quotations from medical sources. The first quotation appeared in one of the earliest texts to be translated from Arabic into Latin, the tenth-century Persian physician al-Majusi's influential introductory text on medicine, the Kitab al-maliki. The treatise provides a detailed overview of Galenic medicine, both theoretical and practical, and was translated twice into Latin. In the earlier translation, the Pantegni by Constantinus Africanus, completed in the second half of the eleventh century, the discussion of insomnia begins:

Sleeplessness is called insomnia [insomneitas], which is a certain disease of the brain … When inordinate sleeplessness arises, anguish follows, the colour changes, worries, thoughts, alienation of the mind, and irrational suspicions are increased, the body grows thinner and dries out, digestion is corrupted, and the individual's whole complexion is changed. [15 (fol. 146va)]

Here the causal model identifies sleeplessness as the instigator of both physiological and mental disturbances, intriguingly intertwined in the passage. The variety of somatic and psychic responses is impressive: from the skin's hue to digestive problems to mental illness (alienation of the mind) to a transformation of the body's entire constitution. The passage appears frequently in medical texts of the central middle ages and was incorporated into the major encyclopaedias of the period, expanding its audience tremendously [46 (7.9)].

The second quotation provides a very different (but not entirely incompatible) argument, focusing not on insomnia's consequences but on its causes. Arnald of Villanova, a prominent physician and professor of medicine at the University of Montpellier in the decades around 1300, observed: ‘Sleeplessness [is] an immoderate and involuntary wakefulness which some call insomnia … It can be caused by sharp and pungent foods, strong words, sharp cries, eager study, pressing worries, and fear' [18 (De parte operativa, fol. 267e)]. Here, again, we find a mix of physical and mental aetiological explanations. Digestive issues appear prominently—as they did in the causal explanations for the incubus and other diseases of sleep—but so do intellectual and psychological issues.

At the same time, physicians and natural philosophers sometimes argued for the opposite effect: worry could produce rather than preclude sleep. Albert the Great states emphatically that ‘cares and fear sometimes induce sleep' and that sleep can occur due to either exhaustion or worries [20 (Summa de creaturis, 385a; and Isagoge in libros de anima, ch. 27, 519b)]. He explained the latter cause of slumber by indicating that worries would dry out the brain and loosen the humours, thereby leading to the onset of sleep. Albert saw no opposition between a physical and a mental causal explanation for sleep, and invoked the humours and the qualities to support the impact of each on the brain and other parts of the body.

An early twelfth-century miracle connected to the church of St Bartholomew the Great in London describes a man from Norwich who suffered from sleeplessness for seven years. The miracle writer begins his story of miraculous healing with a brief encomium to sleep, stating that it is almost unnecessary to praise slumber because the benefits of sleep are so self-evident: ‘it lightens the sweat of the day, and after labour it refreshes a man for [further] labour, and keeps whole and sound the nature not only of men but also of beasts' [47 (ch. 24, pp. 25–6)]. By contrast, the sleepless man suffered enormously, demonstrating the toll which insomnia could take. The illness led to physical transformations (emaciation, premature ageing) as well as social ramifications (he lost his friends and wealth) and undefined mental troubles. The miraculous healing is slightly mundane: he visits a church in Yarmouth (where St Bartholomew's relics were temporarily resting), prayed in front of the relics, and as a reward for his piety fell into a deep sleep, from which he awoke refreshed. The miracle story parallels the medical literature in its emphasis on the deleterious effects of insomnia on various aspects of life.

The medical treatments for sleeplessness emphasized the need to calm and balance both body and mind. While the majority of remedies were pharmacological and advised a wide range of opiates and other calming and cooling substances (wild lettuce, henbane, camomile) to relax the body, the repertoire of remedies also included a number of suggestions which were more clearly focused on countering the mental and emotional causes and/or symptoms. In addition to materia medica to be ingested or absorbed into the body, physicians advocated a form of music or, more broadly, sound therapy: the sufferer was to listen to soothing music, either instrumental or sung, and be able to hear the sound of trees swaying in a light breeze or water trickling over resonant objects such as shells [16 (3.1.4.6); 18 (De parte operativa, fol. 269)]. Several sources identify an aesthetic element to these remedies: the sweet sound of trees or water, delightful melodies and sweet massage serve to soothe the mind and body (but note Henry IV's speech refers to the failure of ‘sweet melodies' to lull the king to sleep). Baths, light massage and light exercise were also advised [48]. The manipulation of the environment and surface of the body brought not only the humours and qualities but also the emotions back into balance and moderation, a model parallel to modern notions of sleep hygiene. In terms of the six non-naturals, four were in play here: the environment, as well as rest and exercise, were used to produce changes both in sleep and in the accidents of the soul. All of these remedies follow the Hippocratic and Galenic principle of allopathic treatment—that is, using remedies considered to be of an opposite quality (for instance, hot instead of cold) to cure a condition by bringing the body back to balance. Even medieval music and sound therapy could be viewed as a form of allopathic remedy in its desire to calm both body and mind.

6. Conclusion

It is unsurprising that we find little evidence of the modern psychological and endocrinological views of stress in earlier periods. Instead, what this study of medieval medicine has found are various phenomena which we now identify as symptoms of stress. The language of anguish, worry, disquiet and anxiety, among others, which we have encountered in texts from the central middle ages, may sound familiar to us, but it is embedded in a physiological and psychological system radically different from our own. Premodern medical ideas of humours, for example, have largely disappeared, beyond occasional instances of archaic language describing someone as melancholic (literally, one who has a predominance of black bile) and thus prone to sadness and worry. Despite these archaic remnants, the language of Galenic humoral medicine no longer sounds familiar.

By contrast, although eighteenth- or nineteenth-century understandings of the nervous system differed considerably from those of modern medicine, the language of fashionable nervous disorders still lingers, at least in popular discourse. In the layperson's tongue, we still describe people as highly strung, tightly wound, overly tense or having frayed nerves, even though Selye and many after him have long since moved beyond this understanding of the nervous system. Even the concept of relaxation seems to reflect the language of tautness or laxity of nerves and thus of the individual's psychological and physical state.

Earlier medical views arose from a pre-Cartesian, pre-neurological understanding of the relation between body and mind (as well as soul), which refused to draw a clear line between the two. Before Descartes' dualist divide, the materials we have analysed suggested a blurring of psyche and soma, mind and body, which did not necessarily prioritize one over the other but revealed a complex interaction of the two. The awareness that worries could cause insomnia was not in conflict with the recognition that sleeplessness caused by humoral imbalance could lead to increased worry. The medical sources indicated a relatively unproblematic blurring of psychological and physical causes, symptoms and remedies.

The importance of the non-naturals in understanding how worry and sleep were thought to be connected brings into focus the central idea of balance in premodern medicine. The medical goal of re-establishing an equilibrium among the humours and the qualities required much more than the manipulation of the physical body. The centrality of the sixth non-natural, the accidents of the soul, in the discussions of sleep and worries required that immoderate emotional states be treated alongside more somatic, humoral imbalance. The treatments for insomnia, with their mix of pharmacology, sound therapy and baths, recognized the importance of treating the body, inside and out, as well as the mind and soul. The holistic nature of such Galenic remedies finds parallels with some modern forms of alternative medicine and sleep regimen, at least in practical terms if not in theoretical outlook. Ultimately, for medieval physicians, the restorative necessity of sleep required that pathological states associated with worries such as disturbing dreams and disturbed sleep patterns—nightmares and insomnia—be treated with care. Premodern physicians recognized that, through careful manipulation of the non-naturals, the human body and mind could be altered and, when properly controlled, could be returned to balance and health.

Data accessibility

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Competing interests

I declare I have no competing interests.

Funding

I received no funding for this study.