Today, it is a common practice to think of sloth as some chic synonym for inactivity or laziness. A failure to work hard, act efficiently, even suggesting what we might call ‘bed-rotting’. But in the medieval tradition, sloth was named one of the seven deadly sins. This classification might feel exaggerated: sloth doesn’t sound all that ‘deadly’. Surely a so-called slothful person is too lazy to do anything dangerous, even if they wanted to? How then did sloth earn a place among the ‘seven deadly sins’?

Deadly for the medievals didn’t mean deadly. These were not the dramatic moral infractions we imagine now, but dispositions that undermined the soul’s orientation toward God, sins that would inevitably lead to damnation. That doesn’t sound much better, but it’s at least helpful in understanding that people in the Middle Ages didn’t literally think that someone was going to die from hanging out in their bed all day.

Originally a monastic vice to do with the boredom of monks in their cell – acedia according to the desert father Evagrius Ponticus (346-399) – was the attack of the ‘noonday demon’, which caused the monk to be spiritually exhausted, restless, listless and sad. It emerged as one of the most serious and threatening maladies, where the heart of the monk was subject to weariness and distress. Unlike other temptations, the effects of acedia threatened the foundations of the monastic vocation, tempting the monk away from his brethren, God, and the religious life itself. It was a vice that primarily attacked those who had dedicated themselves to the contemplative life:

The demon of acedia, also called ‘noonday demon’, is the most oppressive of all demons. He attacks the monk about the fourth hour and besieges his soul until the eighth hour… the demon sends him hatred against the place, against life itself, and against the work of his hands, and makes him think he has lost the love among his brethren and that there is none to comfort him.

But it did not remain within the confines of the monastery. From about 1200 the scope of the vice extended to include lay people. This expansion was partly the result of the 13th-century pastoral revolution, in which lay piety and pastoral care were given unprecedented attention, especially following the fourth Lateran Council in 1215. Acedia, once tied to the monk’s failure to keep the Divine Office now signified the failure of any Christian to make time for prayer and contemplation, marking a refusal of one’s spiritual duties, not simply a monk’s faltering vocation.

This is reflected in the enormous number of scholastic treatises which deal explicitly with the vice: Guillaume d’Auxerre (1145-1231), Alexander of Hales (1185-1245), William Peraldus (1190-1271), Albert the Great (c.1200-80) and Thomas Aquinas (c. 1225-74). The emphasis in these Summae was not only on the emotional distress that comes with sloth, but on its manifestations, as neglect and paradoxically, as busyness.

The exposition of sloth and of the seven deadly sins more broadly in the work of English poet Geoffrey Chaucer (c.1343-1400) is typical of this 13th-century view. As Morton W. Bloomfield and others have argued, Chaucer likely drew on William Peraldus’ influential Summa, which shaped much late-medieval preaching on the virtues and vices.

The most explicit treatment of acedia in Chaucer appears in the ‘Parson’s Tale’, the concluding text of the Canterbury Tales. There, the speaker, a parson devout to his parish, devotes an entire section to ‘slouthe’ and its remedies. He defines sloth as ‘the angwissh of troubled herte’, locating it, like the scholastics, in an interior resistance to divine good. The slothful soul, he observes, becomes ‘hevy, thoghtful, and wrawe’, a cluster of adjectives that evokes both the physical and psychological effects of the vice.

The parson then, in quite a scholarly manner, lists 11 of acedia’s offspring, a catalogue whose precision clearly reflects the inherited scholastic taxonomy. Among them are ‘drede to biginne to werke any goode werkes’; ‘wanhope’; ‘sompnolence’; ‘necligence’; ‘idelnesse’; ‘tartinge er he wole turne to God’; ‘lachesse’; ‘cooldnesse’;  ‘undevocioun’; ‘slough and slombry’; ‘worldly sorwe’ and, finally,  ‘tristicia’. Each of these corresponds to a subvice in the Latin system set out in the Summae above.

Taken together, Chaucer’s exposition via the parson offers a remarkably comprehensive portrait of the vice. Each term names a particular distortion of the soul’s response to the good, and the accumulation of synonyms is itself instructive. Acedia is not reducible to a single feeling or failure but designates a whole cluster of resistances: hesitation (‘tartinge’), paralysis (‘drede to biginne’), sensory dullness (‘somnolence’), habitual neglect (‘necligence’), and affective tepidity (‘cooldnesse’ and ‘undevocioun’). Some of these words emphasise interior affect, ‘tristicia’ and ‘worldly sorwe’ marking the sorrowing experience of the vice, while others describe behavioural patterns such as idleness, slackness, or the restless half-wakefulness of ‘slough and slombry’. This kind of sloth is an aversion or a shrinking from the labour of charity and the attentiveness required for the love of God, turning away from the gifts that make human flourishing possible.

According to the parson, the remedium to sloth is fortitudo, or strength. Where these medieval writers often imagine acedia as a loosening, a spiritual slackness, fortitude was seen to restore tension, drawing the person back into a shape capable of sustained devotion, helping us to love, and have hope in, God and the world.

Other references to sloth in Chaucer’s work can help to clarify his position here. Like in the Parson’s Tale, which says that the slothful ‘loveth no bisinesse at al’, in his stand-alone poem ‘Gentilesse’ he writes that: ‘This firste stok was ful of rightwisnesse, / Trewe of his word, sobre, pitous, and free, / Clene of his gost, and loved besinesse, / Ayeinst the vyce of slouthe, in honestee.’

This, as we have begun to uncover, does not amount to an endorsement of industriousness. Medieval writers recognised that activity could be either virtuous or vicious, depending on its orientation: the restless busyness born of acedia, driven by distraction or avoidance, is slothful. What Chaucer praises, therefore, is a rightly ordered form of bisinesse; works which are grounded in charity, and stability of heart.

The Second Nun’s tale of his Canterbury Tales begins with a prologue where the nun explains the value of diligence and the dangers of idleness (‘Ydelnesse’). Here, she suggests that work is the antidote to idleness: ‘Wel oghte us werche and ydelnesse withstonde.’

Now, when we modern folk have ‘work’ in mind, I expect it would not be a stretch to say that we are imagining useful labour, physical graft or toil. But, according to the Catholic philosopher Josef Pieper, the medieval imagination would have understood work to be made up of both the servile and the liberal arts. Servile work refers to the kinds of labour considered unsuitable for the ‘holy rest’ of the Sabbath. In other words, tasks tied to necessity, production, and the maintenance of life. This is only half of the picture. The kind of work that the nun would have had in mind would certainly have been spiritual. Accordingly, the nun recites an invocation to the Virgin Mary (‘Invocacio ad Mariam’).

This sets up Saint Cecilia as the anti-exempla of the vice: ‘And right so as thise philosophres write /  That hevene is swift and round and eek brennynge, / Right so was faire Cecilie the white / Ful swift and bisy evere in good werkynge / And round and hool in good perseverynge, / And brennynge evere in charite ful brighte. / Now have I yow declared what she highte.’

Celestial swiftness, circularity, burning brightness are linked here directly to moral qualities: energetic devotion, steadfast perseverance, and fervent charity. In doing so, the passage establishes a cosmic hierarchy in which spiritual vitality mirrors the ordered motion of the heavens, wherein sloth represents its disordered opposite. St Cecilia embodies the lively, continuous, love-driven motion that is resisted by the slothful souls.

By presenting Cecilia as ‘swift’, ‘round’, and ‘burning’, Chaucer also solidifies her work as spiritual, or leisurely. As Pieper has shown, in the Middle Ages ‘leisure’ did not mean self-indulgent free time in the modern sense. Deriving from the Greek σχoλη ́, and the Latin scola (notably where we get the word ‘school’ from), it referred to the interior labour that makes contemplation, study and prayer possible. This is the kind of work denoted by the liberal arts. These activities are ordered toward the cultivation of the soul: contemplation, study, prayer, music and the forms of intellectual-spiritual work that free a person to apprehend the good.

Ironically, it was the lack of leisure that could produce sloth. Cecilia’s ‘bisy’ good works arise from leisure itself. Like the ordered motion of the heavens, Cecilia’s activity flows from an inner wholeness (‘round and hool’) and an inward orientation toward the good (‘brennynge evere in charite’).

Clearly, the physical effects of the vice are notable, though not sacrosanct. Under such an account, the diligent scholar moored to his desk all day contemplating the good is the antithesis of the vice. But, equally, a busy person running around the city, ticking off at least one thing on their to-do list per hour might be suffering from it.

By the mid- to late-14th century, then, we can see that sloth had developed into an extraordinarily complex and technical term, with very specific boundaries, distinctions, and remedies, but its focus shifted over time. From a vice concerning the soul’s orientation toward divine love, it came increasingly to be interpreted in terms of social and economic activity, a change which would only be accelerated in early modern cities

Unlike many of the technical terms of the church at the time, the teaching of acedia was not restricted to the scholastics, but was a part of general religious education and life: popularised in devotional literature, handbooks and sermons. In transforming sloth from a monastic vice to general vice, Siegfried Wenzel has suggested we tended to focus on its effects (like physical laziness or tiredness, for example) as a way of dealing with it in the confession – it was a liturgical concern. And so sloth came to be associated increasingly only with its bodily effects.

This, alongside the prodigious economic transformation of European cities, meant that, by the time we reach 1500, it had essentially become a synonym for indolence. We see this for example in the work of Thomas Dekker (1572-1632), an English dramatist and writer for whom sloth and laziness are one and the same thing entirely:

How then dares this nastie, and loathsome sin of Sloth ventre into a Citie amongst so many people?… heere are Porters sweating vnder burdens, there are Marchants-men bearing bags of money, Chapmen (as if they were at Leape frog) skippe out of one shop into another: Tradesmen (as if they were dauncing Galliards) are lusty at legged and neuer stand still: all are as busie as countrie Atturneyes at an Assisses: how then can Idlenes thinke to inhabit heere?

Dekker’s London is a cesspit of movement: porters ‘sweating’, merchants bearing money, shopkeepers darting about like boys playing leapfrog. But his suggestion is that activity itself is proof of virtue, or at least of absence of vice. In such a world, there is no conceptual space left for contemplative rest or leisure as part of work. The only remaining contrast is between physical motion (good) and physical stillness (bad). Sloth, he says, is therefore the ‘founder of Almeshouses’, cementing the idea that sloth is antithetical to useful work, and not leisure as the medievals had it.

As Michael Perelman’s influential The Invention of Capitalism has shown, religious attitudes around sloth in the 18^th century denounced any behaviour of the working classes that did not ‘yield a maximum of work effort.’ Francis Hutcheson, an 18^th-century Scottish philosopher, quoted in the same book, wrote that ‘If a people have not acquired an habit of industry, the cheapness of all the necessaries of life encourages sloth. The best remedy is to raise the demand for all necessaries… Sloth should be punished by temporary servitude at least.’ This is a picture of sloth you and I will be familiar with, although hopefully you and I, unlike Hutcheson and others of his time and ours, wouldn’t condemn the indolent to ‘temporary servitude at least’.

Fast forwarding to our contemporary time, the meaning of sloth has been virtually erased. Have we done away with it? Or has it been forgotten? The entire concept of a spiritual good, or spiritual work is foreign to us modern readers. Sloth has increasingly become less about the state of the soul and more about economic behaviour. What is at stake is now one’s contribution to the economy, the household, and society at large. In this context, industriousness became a civic and economic duty, and sloth was framed as a threat to social order rather than a spiritual danger. This shift reveals broader transformations: the rise of financialised economies, the secularisation of moral judgement, and the growing tendency of a utilitarian system to measure worth in terms of productivity rather than virtue.

To be clear, productivity and work are an absolutely essential part of human life and human flourishing. But they are not the whole of it. As we have already said, premodern thinkers understood that genuine human flourishing requires both labour and forms of work that are not measurable by productivity metrics. Our economic structures, however, overwhelmingly reward the restless activity that medieval writers would have identified as a feature of acedia.

Recognising that sloth can take the form not only of idleness but of industriousness gives the concept a renewed importance. In a culture that prizes productivity, optimisation and self-management, sloth survives mostly as a joke, reduced to caricatures of couch-potatoes and sleepy cartoon animals. This trivialisation itself is symptomatic of the loss: we no longer recognise the spiritual restlessness, the incapacity for presence, the quiet refusal of the good that earlier medieval thinkers saw at the core of sloth.

This narrowed moral vocabulary has shaped the way we perceive the liberal arts and humanities. A culture that recognises only measurable labour, the result of a utilitarian mode of economic management, inevitably sees forms of contemplative work as idle or indulgent. In other words, the humanities appear ‘slothful’ only within a framework that has forgotten that work includes contemplative work as well.

This tension has come to a head in the institutions where spiritual and intellectual work are practised most fastidiously. In recent years, the humanities have come under increasing pressure to produce ‘useful’ research. But the forms of work cultivated by the humanities, that is, reflection, moral imagination, aesthetic attention, the careful study of human experience, are precisely the forms of labour that cannot be measured in immediate output or profit. In a society increasingly obsessed with utility and efficiency, the qualities that make the humanities vulnerable to these critiques are the ones that make them essential: they train us to think, to feel, and to inhabit the world in ways that resist the spiritual and emotional impoverishment that modern sloth engenders.

In dispensing with sloth as a meaningful category, we risk losing the language for what remains remarkably relevant in contemporary life: the restlessness and busyness that masks our inability to attend to our own thinking, to sustain contemplation, to engage deeply with ideas. This is a culture that is ripe for the devaluation of the humanities. Reclaiming this history of sloth, from the desert monks to Chaucer’s poetics, reminds us that contemplation is not an indulgent luxury, nor is it slothful. It is a recognition that the human spirit requires forms of labour, rest, and leisure that cannot always be reduced to productivity, yet are essential to our wellbeing as well as our flourishing. There is something beyond mere use, after all.