The first half of the eighteenth century witnessed a profound transition in the understanding of mental illness. Although older religious explanations—particularly ideas of demonic influence, divine judgement, or moral failure—had by no means disappeared, they increasingly coexisted with new philosophical and medical attempts to explain disordered thought through natural causes. This was not yet the age of modern psychiatry, but it was an era in which insanity began to move from the realm of theology and criminal law into that of medicine, philosophy, and institutional care.

A crucial intellectual foundation was laid by John Locke’s An Essay Concerning Human Understanding (1690). Locke’s account of the human mind profoundly influenced eighteenth-century conceptions of reason and madness. Rather than viewing insanity as the complete loss of reason, Locke argued that almost every person possessed some degree of irrationality. Human beings constantly formed false associations between ideas because strong emotions distorted judgement. Madness, therefore, consisted not in the absence of reason but in the persistent inability to connect ideas correctly according to experience. The rational faculties remained present, but they had become imprisoned by erroneous associations that the sufferer could no longer correct.

This seemingly philosophical distinction had enormous practical consequences. If madness resulted from the malfunctioning of ordinary mental processes rather than supernatural intervention, it could be studied, classified, and perhaps even treated. Locke’s psychology provided an intellectual framework that shaped English thinking throughout the eighteenth century and quietly encouraged physicians to regard disorders of the mind as legitimate objects of scientific inquiry.

Medical historian Erwin Ackerknecht famously argued that the eighteenth century marked the period when psychiatry “reached the status of an independent science.” Significantly, he maintained that this transformation owed less to advances in medicine than to the broader intellectual climate of the Enlightenment. As belief in demonic possession gradually lost credibility among educated thinkers, insanity came increasingly to be understood as a disorder of the brain or of the “thinking apparatus.” Since Enlightenment philosophy attached supreme importance to reason, those deprived of rationality became objects not merely of fear but also of sympathy and investigation. Cartesian philosophy further encouraged physicians to distinguish mental processes from purely bodily disease while simultaneously allowing psychological explanation to enter medical discourse. The result was not the abandonment of physical medicine but the emergence of a more complex understanding in which mind and body interacted in ways that demanded careful observation.

These intellectual developments were accompanied by slow but significant changes in institutional provision. At the beginning of the eighteenth century England possessed remarkably few places specifically devoted to the care of the mentally ill. The largest and best known was Bethlem Hospital in London—popularly known as Bedlam—which housed approximately 130 patients in 1704. Despite its notoriety, Bethlem remained exceptional. Most counties possessed no dedicated asylum, and individuals suffering mental illness were instead cared for by their families, confined within parish workhouses, imprisoned in houses of correction, or admitted to general hospitals if they became violent or unmanageable.

Alongside Bethlem there emerged an expanding network of private madhouses. One of the earliest was Hoxton House, which became a private madhouse in 1695 and would remain one of London’s principal establishments for more than a century. By 1800 perhaps forty licensed private madhouses existed throughout England, although their numbers before licensing legislation remain uncertain. These institutions varied enormously in quality. Some developed reputations for humane treatment, while others became synonymous with neglect, exploitation, and indefinite confinement.

One advertisement from the turn of the century illustrates both the commercial character of these establishments and contemporary ideas about treatment. Around 1700, David Irish, proprietor of a madhouse near Guildford, promised prospective families that patients would receive comforts surpassing those available at Bedlam:

“…allowing them good fires, meat, and drink, with good attendance… he allows the melancholy, mad, and such whose consciences are oppressed with a sense of sin, good meat every day for dinner… wholesome diet for breakfast and supper, and good table-beer enough at any time.”

This advertisement is striking for several reasons. First, Irish distinguished between different forms of mental suffering, including melancholy and religious despair, suggesting that these were recognised as distinct conditions requiring care. Secondly, his emphasis rested not upon dramatic medical interventions but upon warmth, nourishment, regular meals, attentive supervision, and domestic comfort. Although commercial motives undoubtedly lay behind such claims, they nevertheless reveal that good management and environment were already regarded as therapeutic resources.

Institutional provision also expanded through charitable initiative. In 1713 the Norwich Bethel opened as England’s first charitable madhouse outside Bethlem. Established through private benefaction in what was then England’s second-largest city, the Bethel represented an important new model of civic responsibility. Housing twenty-eight patients by 1753, it anticipated the series of voluntary hospitals that would later appear across England in cities such as Manchester, Newcastle, York, Liverpool, Leicester, Hereford, and Exeter. Unlike the profit-driven private madhouses, these charitable institutions sought to provide organised care for those who otherwise lacked access to treatment.

Mental illness also increasingly entered the framework of English law. The Vagrancy Act of 1714 is generally regarded as the first English statute to make explicit provision for the detention of persons described as lunatics, although legal commentators such as William Blackstone later argued that it merely formalised principles already recognised in the common law. Whatever its precise legal origins, the legislation reflected growing governmental concern over public order and the management of those considered incapable of governing themselves. Similar concerns would be reinforced by the Vagrancy Act of 1744, which further clarified procedures for confinement.

General hospitals likewise began to acknowledge mental illness as part of ordinary medical practice. In 1723 Guy’s Hospital opened dedicated lunatic wards, recognising that insanity belonged within the range of conditions requiring organised institutional treatment rather than simple exclusion from society. Although such wards remained small and treatment options limited, their existence reflected an important shift in medical thinking.

During these same decades physicians attempted to define insanity with greater precision. One landmark moment occurred in 1724 during the trial of Edward Arnold, charged with the murder of Lord Onslow. The resulting judicial formulation, later known as the “wild beast test,” held that criminal responsibility was absent only if the accused possessed no more understanding than “an infant, a brute, or a wild beast.” Although crude by modern standards, the test represented one of the earliest attempts in English law to articulate a coherent relationship between mental illness and criminal responsibility.

Medical literature similarly expanded. Richard Blackmore’s Treatise of the Spleen and Vapours (1725) examined melancholy, nervous disorders, and emotional disturbance within an increasingly medical framework. Such works contributed to a growing body of literature that linked bodily processes, nerves, imagination, and emotional life. Rather than treating mental illness as wholly separate from physical disease, physicians increasingly explored the interaction between body, passions, and mind—a theme that would become central throughout the century.

Perhaps no physician embodied the established medical management of insanity more fully than James Monro, resident physician at Bethlem Hospital from 1728 until 1752. Monro belonged to a remarkable medical dynasty that dominated Bethlem for more than a century. His practice reflected the prevailing medical orthodoxy of the period, employing purging, bleeding, blistering, and other evacuative therapies intended to restore bodily balance. Yet his long tenure also symbolised the emergence of specialist physicians whose principal professional identity lay in the treatment of mental disorder.

Public perceptions of madness were vividly captured by William Hogarth’s A Rake’s Progress (1735). The final engraving famously depicts the ruined Tom Rakewell confined within Bedlam after a life of extravagance, gambling, prostitution, and financial ruin. Madness appears not simply as illness but as the tragic culmination of moral, social, and psychological collapse. Hogarth’s image simultaneously reflects contemporary fascination with insanity and exposes the uncomfortable reality that London’s principal asylum had become a public spectacle visited by curious onlookers.

Yet criticism of the system was already emerging. In 1738 Alexander Cruden, later celebrated for compiling Cruden’s Concordance, escaped from Wright’s private madhouse in Bethnal Green and successfully appealed to the Lord Mayor to prevent his forcible return. His subsequent pamphlet, The London-Citizen Exceedingly Injured (1739), argued passionately for stricter regulation of private madhouses and highlighted the ease with which inconvenient individuals could be confined without adequate legal safeguards. Cruden’s protest anticipated the licensing reforms introduced later in the century and remains one of the earliest public critiques of psychiatric detention in Britain.

The years immediately following also intersect with the beginnings of the Evangelical Revival. In May 1738 the evangelical conversions of John and Charles Wesley inaugurated a movement whose concern for both bodily and spiritual health would profoundly influence later approaches to mental suffering. Wesley’s journals already reveal encounters with individuals experiencing severe emotional and psychological disturbance. Particularly revealing is a letter written by Susanna Wesley in December 1740 describing a man sent to a Chelsea madhouse by “that wretched fellow Monro,” whom she believed stood in greater need of “a spiritual than bodily physician.” Her comment captures the continuing tension between medical confinement and pastoral care that characterised much eighteenth-century thinking. For the Wesleys, disorders of the mind required compassionate discernment that neither reduced all suffering to spiritual failure nor ignored the legitimate role of medical treatment.

By the middle of the century, therefore, Britain possessed no coherent national system of mental healthcare. Provision remained fragmented between families, parishes, workhouses, charitable institutions, private madhouses, hospitals, and the criminal justice system. Nevertheless, the foundations of modern psychiatry had begun to emerge. Enlightenment philosophy had redefined madness as a disorder of reason rather than supernatural possession; physicians were increasingly classifying and describing mental disorders; charitable asylums were expanding; and both law and medicine were slowly recognising that mental illness demanded specialised forms of care. These developments formed the complex and often contradictory world into which John Wesley would introduce his own distinctive synthesis of practical medicine, pastoral theology, and compassionate concern for those afflicted in mind as well as body.

The eighteenth century occupies a pivotal place in the history of mental illness. It was neither wholly superstitious nor recognisably modern. Instead, it was an age of transition in which medieval beliefs about madness gradually gave way to medical investigation, while moral and religious interpretations continued to shape both diagnosis and treatment. Physicians, clergy, philosophers, and family members all played significant roles in caring for those experiencing mental distress. Although many treatments now appear ineffective or even cruel, the century also witnessed important advances in understanding the relationship between the mind, brain, nerves, emotions, and environment.

From Madness to Mental Disease

Earlier centuries had often interpreted madness as divine punishment, demonic possession, or moral failure. By the eighteenth century, these explanations had not disappeared, but increasingly they existed alongside medical theories.

The Enlightenment encouraged physicians to believe that mental disorders, like physical diseases, had natural causes that could be observed, classified, and treated. Madness gradually became something that physicians rather than priests increasingly claimed authority to explain.

This shift was reflected in changing vocabulary. Terms such as:

• melancholy
• mania
• frenzy
• lunacy
• hypochondria
• vapours
• hysteria
• delirium

began to acquire more precise medical meanings, although they remained fluid and overlapping.

The Rise of Nervous Medicine

Perhaps the most influential development was the emergence of nervous medicine.

Physicians increasingly viewed the nervous system as the body’s communication network. Emotional experiences, imagination, memory, sleep, digestion and physical illness were all believed to affect the nerves.

Leading contributors included:

Thomas Sydenham (1624–1689)

Often called the “English Hippocrates,” Sydenham argued that careful clinical observation should replace speculative theories.

Although best known for physical diseases, he recognised that emotional disturbances had bodily causes and rejected supernatural explanations.

Herman Boerhaave (1668–1738)

Boerhaave integrated anatomy, physiology and bedside medicine.

He regarded mental disorders as arising through disturbances of bodily organs, especially the brain and nervous system. His teaching at Leiden influenced physicians throughout Europe, including many read by John Wesley.

George Cheyne (1671–1743)

Cheyne transformed understanding of what became known as “the English Malady.”

He believed affluent lifestyles—rich food, alcohol, inactivity, excessive study and emotional strain—produced nervous disorders.

His The English Malady (1733) described symptoms including:

• depression
• anxiety
• panic
• obsessive thoughts
• exhaustion
• memory impairment
• religious despair

Remarkably, many resemble modern descriptions of mood disorders.

Cheyne recommended:

• exercise
• walking
• fresh air
• simpler diet
• moderation
• conversation
• religious consolation

rather than punishment.

Robert Whytt (1714–1766)

Whytt developed sophisticated theories about the nervous system.

He proposed that involuntary bodily responses reflected a “sentient principle” linking mind and body.

His work explained many psychological symptoms without denying human spirituality, making him influential among both physicians and theologians.

William Cullen (1710–1790)

Cullen produced one of the century’s most systematic classifications of disease.

He placed many mental illnesses within his category of neuroses, arguing that disorders of the nervous system could disturb:

• judgment
• memory
• imagination
• emotions
• behaviour

His taxonomy strongly influenced nineteenth-century psychiatry.

Common Diagnoses

Melancholy

Melancholy remained one of the commonest diagnoses.

Symptoms included:

• sadness
• withdrawal
• insomnia
• fear
• religious despair
• fixed delusions
• suicidal thoughts

Many physicians distinguished melancholy from complete madness because reasoning remained intact except concerning one dominant idea.

Mania

Mania referred to violent excitement.

Symptoms included:

• aggression
• sleeplessness
• grandiosity
• rapid speech
• confusion
• impulsivity

Delirium

Unlike madness, delirium usually accompanied fever or severe illness.

Patients became confused, disorientated and hallucinatory.

Physicians carefully distinguished delirium from insanity because treatment depended upon identifying the underlying physical disease.

Hypochondriasis

Far broader than today’s usage.

Hypochondriacal disorders included:

• digestive complaints
• anxiety
• low mood
• obsessive fears
• fatigue
• bodily sensations without obvious cause

Hysteria

Originally associated with women, hysteria gradually became understood as another nervous disorder rather than purely a disease of the womb.

Treatments

Treatment aimed to restore balance within the body and nerves.

Bleeding

Bloodletting remained common.

Many physicians believed excessive blood congested the brain and aggravated madness.

Although now known to be ineffective in most cases, it reflected contemporary physiological theories.

Purging and Emetics

Patients often received:

• laxatives
• vomiting agents
• enemas

These were intended to remove harmful substances from the body.

Diet

Diet occupied an important place.

Cheyne advocated:

• vegetables
• milk
• simple foods

while discouraging:

• heavy meat
• alcohol
• rich sauces

Exercise

Walking became one of the century’s favourite therapies.

Fresh air, gardening, riding and manual labour were believed to calm the nerves.

John Wesley later echoed many of these recommendations in Primitive Physick.

Sleep

Physicians recognised the intimate relationship between sleep and mental health.

Insomnia could both cause and worsen mental illness.

Cold Baths

Cold bathing became fashionable.

Many believed sudden immersion strengthened weakened nerves.

Opium

Laudanum (opium dissolved in alcohol) was widely prescribed.

It relieved anxiety and promoted sleep, although physicians increasingly recognised problems of dependency.

Moral Treatment Before Moral Treatment

The famous nineteenth-century “moral treatment” associated with Philippe Pinel and William Tuke had eighteenth-century roots.

Even before these reforms, some physicians stressed:

• kindness
• reassurance
• conversation
• structured routine
• useful occupation

rather than constant physical restraint.

Bethlem Hospital (“Bedlam”)

The century’s most notorious asylum remained Bethlem Hospital in London.

Conditions varied considerably over time.

Early eighteenth-century reports describe:

• chains
• public visitors
• overcrowding
• poor hygiene

Yet by the century’s end increasing criticism led to reforms.

Public attitudes towards mental illness slowly shifted from spectacle toward compassion.

Religion and Mental Illness

Religion remained enormously influential.

Many clergy interpreted melancholy as:

• temptation
• spiritual trial
• excessive scrupulosity

rather than demonic possession.

John Wesley offers a fascinating example.

He accepted medical explanations while simultaneously believing:

• prayer mattered,
• bodily remedies mattered,
• community mattered,
• spiritual hope mattered.

Rather than separating medicine from theology, Wesley integrated them.

The Role of Imagination

Eighteenth-century physicians frequently blamed excessive imagination for mental disturbance.

Powerful mental images were believed capable of producing bodily illness.

Whytt, Cheyne and Cullen all discussed imagination extensively.

At the same time they recognised that imagination could also assist healing through hope, reassurance and religious devotion.

Towards Modern Psychiatry

By 1800 several important developments had emerged:

• mental illness increasingly viewed as disease rather than possession;
• careful clinical observation replacing speculation;
• classification of disorders becoming systematic;
• nervous physiology linking mind and body;
• humane treatment receiving greater attention;
• hospitals beginning gradual reform.

Nevertheless, many misconceptions remained. Effective drug therapies lay more than a century in the future, and neurological diseases such as dementia, Parkinson’s disease, epilepsy and delirium were often difficult to distinguish from one another.

Significance

The eighteenth century should not simply be remembered as an age of “Bedlam” and barbaric treatments. It was equally an age of remarkable intellectual innovation. Physicians such as Sydenham, Boerhaave, Cheyne, Whytt, Battie and Cullen laid many of the conceptual foundations upon which modern psychiatry, neurology and psychology would later build. Their attempts to understand the interactions between body, brain, emotions, imagination and environment moved medicine decisively away from supernatural explanations towards empirical investigation. Although constrained by the scientific knowledge of their time, they recognised that mental suffering was often inseparable from physical health, social circumstances and emotional experience—a holistic insight that continues to inform contemporary approaches to mental healthcare.

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St Luke’s Hospital for Lunatics (1751): Britain’s First Purpose-Built Enlightenment Mental Hospital

If Bethlem (“Bedlam”) represented the old world of confinement, St Luke’s Hospital for Lunatics represented the aspirations of the Enlightenment. Founded in 1751, St Luke’s attempted to place the treatment of mental illness on a more medical and humane footing. Although many of its practices would now be regarded as harsh, it marked an important turning point in British psychiatry and formed the institutional setting in which many of the leading physicians of the eighteenth century—including William Battie—developed new approaches to insanity. 

Why was St Luke’s Founded?

By the middle of the eighteenth century, London’s only public institution for the mentally ill was Bethlem Hospital. Bethlem had become notorious for overcrowding, inadequate care, and the public exhibition of patients, who could be viewed by paying visitors as a form of entertainment. These abuses increasingly troubled physicians and philanthropists influenced by Enlightenment ideals.

In June 1750, a group of London physicians, merchants and benefactors met to establish a new charitable hospital “for poor lunatics” whose illnesses were considered potentially curable. The hospital was supported by public subscription and formally opened the following year. Its founders hoped to provide a therapeutic alternative to Bethlem rather than merely another place of confinement. 

William Battie: Physician and Reformer

No individual shaped St Luke’s more profoundly than Dr William Battie (1703–1776), its first physician.

Battie occupies a central place in the history of psychiatry because he argued that insanity should be regarded as a medical disorder requiring clinical observation rather than moral condemnation. In his influential Treatise on Madness (1758), written while serving at St Luke’s, he rejected simplistic theories of a single cause of madness and argued that insanity consisted of a variety of diseases requiring careful diagnosis and individualized treatment.

His famous criticism of Bethlem’s methods sparked a celebrated controversy with its physician, John Monro. Their debate became one of the first major public disputes over psychiatric treatment in Britain and helped establish “mad-doctoring” as a recognised medical specialty. 

A Hospital Built for Cure

One significant difference between St Luke’s and many earlier institutions was its emphasis upon curability.

Patients admitted were generally expected to have:

• relatively recent onset of illness;
• some prospect of recovery;
• no obvious irreversible cognitive decline.

Those judged incurable were often excluded or discharged after prolonged admission. Consequently, St Luke’s regarded itself less as a permanent asylum than as a therapeutic hospital.

This distinction reflects an important shift in eighteenth-century medicine: insanity was increasingly viewed as something that could sometimes be successfully treated rather than simply managed. 

Medical Theory in Practice

Treatment at St Luke’s reflected the best medical knowledge available at the time, even though many interventions now appear misguided.

Physicians believed insanity often resulted from disturbances affecting the brain, nerves, circulation or digestive system. Accordingly, treatment sought to restore bodily balance through:

• controlled diet;
• regulated sleep;
• exercise;
• purgatives;
• emetics;
• antispasmodic medicines;
• cold bathing.

The famous plunge bath became one of the hospital’s most recognisable therapeutic devices. Sudden immersion in cold water was believed capable of interrupting disordered nervous activity and restoring mental equilibrium. Gastrointestinal treatments remained equally prominent because physicians assumed close connections between digestion and mental function. 

Humanity and Its Limits

Compared with Bethlem, St Luke’s adopted several progressive principles.

Perhaps most notably, patients were not displayed to the public. Battie insisted that the dignity of the mentally ill should be respected and that they should not become objects of curiosity. This represented an important ethical advance over the spectacle associated with Bedlam. 

Yet historians rightly caution against romanticising the institution. Although its ideals were enlightened, practice remained constrained by eighteenth-century medical assumptions. Mechanical restraints, including manacles, were still employed in some circumstances. Isolation cells existed, and many patients lived in sparsely furnished rooms with little heating. The aspiration to humane care coexisted with coercive methods that later reformers would reject. 

Architecture as Therapy

The hospital’s physical design reflected changing ideas about treatment.

The first St Luke’s occupied a converted foundry near Moorfields, but increasing demand led to the construction of a much larger building in Old Street, opened in 1786 and designed by George Dance the Younger. The impressive classical façade projected civic confidence and suggested that mental illness deserved the same architectural dignity as other branches of medicine. Behind the elegant exterior lay separate male and female wards, airing courts for supervised exercise, and approximately 300 single rooms intended to provide order, security and observation. 

The contrast between the magnificent exterior and austere interior has often been noted. Patients’ rooms were simple, with high windows, sparse furnishings and straw bedding for many inmates. Nevertheless, the provision of exercise yards and greater privacy marked an advance over earlier custodial institutions. 

St Luke’s and John Wesley

Although no evidence suggests that John Wesley had a formal connection with St Luke’s, there are striking intellectual parallels between Wesley’s medical writings and those of physicians associated with the hospital.

Like Battie, Wesley rejected the assumption that every disturbance of mind reflected demonic influence or moral failure. His Primitive Physick recommended attention to bodily health, diet, sleep, exercise and fresh air while integrating these with prayer and pastoral care. Wesley’s extensive reading of Boerhaave, Sydenham, Cheyne, Whytt and Cullen placed him within the same broad intellectual movement that increasingly interpreted mental suffering through the physiology of the nerves rather than through supernatural explanation alone.

For a study of Wesley’s understanding of delirium, melancholy and disorders of memory, St Luke’s therefore provides an illuminating institutional context: it exemplifies the medical culture in which many of the ideas informing his pastoral practice were developing.

Historical Significance

St Luke’s occupies a crucial place in the evolution of psychiatry because it represents the transition from custodial confinement to therapeutic aspiration. Its physicians attempted to classify mental disorders systematically, to distinguish potentially curable illnesses from chronic conditions, and to ground treatment in observation rather than superstition. Although many therapies were ineffective by modern standards, the hospital embodied a significant change in attitude: those suffering from mental illness were increasingly regarded as patients rather than spectacles or criminals.

In this sense, St Luke’s stands alongside the writings of Battie, Cheyne, Whytt and Cullen as one of the principal institutions through which eighteenth-century Britain laid the intellectual foundations of modern psychiatry. Its history also reminds us that medical progress is rarely straightforward. Genuine humanitarian advances often coexist with practices that later generations find deeply troubling. St Luke’s thus exemplifies both the promise and the limitations of Enlightenment medicine.