Coleridge and the Geometric Idiom — Walking with Euclid
In the 2023 book published by Cambridge University Press, Ann C. Colley outlines Coleridge’s alertness to the geometric idiom that helped shaped his responses to the landscape of his surroundings. In particular, Colley explains why Euclid’s Elements was such a basic text in Coleridge’s cultural context. To guide the reader, the introduction outlines the book’s argument. Chapter summaries provide an overview of Colley's research conducted as a Visiting Fellow at Wolfson College.

Introduction
When Coleridge described the landscapes he passed through while scrambling among the fells, mountains, and valleys of Britain, he did something unprecedented in Romantic writing: to capture what emerged before his eyes, he enlisted a geometric idiom. Immersed in a culture still beholden to Euclid's Elements and schooled by those who subscribed to its principles, he valued geometry both for its pragmatic function and for its role as a conduit to abstract thought. Indeed, his geometric training would often structure his observations on religion, aesthetics, politics, and philosophy. For Coleridge, however, this perspective never competed with his sensitivity to the organic nature of his surroundings but, rather, intermingled with it. Situating Coleridge's remarkable ways of seeing within the history and teaching of mathematics and alongside the eighteenth century's budding interest in nonEuclidean geometry, Ann Colley illuminates the richness of the culture of walking and the surprising potential of landscape writing.
When Coleridge described the landscapes he passed through while scrambling among the fells, mountains, and valleys of Britain, he did something unprecedented in Romantic writing: to capture what emerged before his eyes, he enlisted a geometric idiom. Immersed in a culture still beholden to Euclid's Elements and schooled by those who subscribed to its principles, he valued geometry both for its pragmatic function and for its role as a conduit to abstract thought. Indeed, his geometric training would often structure his observations on religion, aesthetics, politics, and philosophy. For Coleridge, however, this perspective never competed with his sensitivity to the organic nature of his surroundings but, rather, intermingled with it. Situating Coleridge's remarkable ways of seeing within the history and teaching of mathematics and alongside the eighteenth century's budding interest in nonEuclidean geometry, Ann Colley illuminates the richness of the culture of walking and the surprising potential of landscape writing.
CHAPTER SUMMARIES
Chapter 1. Coleridge Walks
The Measure of the Landscape
The first chapter describes the rough and tumble of Coleridge’s rambles between 1794 and 1804. The chapter opens by placing these excursions within a culture of walking. It depicts his propensity to be his own pathmaker rather than follow either the directives of the picturesque guides or the assigned routes of maps. Entries in his pocket notebooks reveal Coleridge’s understanding of a landscape based both upon what his eyes could see and what his feet could register. In many respects, he becomes a surveyor who measures the terrain with his boots. Often modeling his understanding of a landscape on the spirit of geometric exercises, Coleridge measured and counted his paces over a portion of ground in order to observe its lines and angles.
Chapter 2. Lines of Motion
When Coleridge trod through his surroundings, he was exceptionally alert to the tangible lines that run through and add character to a landscape. He visually traced their presence in the areas through which he rambled and attended to what he termed a landscape’s “lines of motion.” Throughout his early notebook entries, Coleridge plotted these lines to create diagrammatic sketches that recall the geometric idiom. Participating in a diagrammatic culture, Coleridge liked to capture the defining lines of a place and integrate them into his verbal descriptions. Throughout these entries, there lurks his training in Euclidean geometry. Far more than in the work of his fellow poets and writers, this background is very much at play in Coleridge’s landscape descriptions.
Chapter 3. A Geometric Frame of Mind
While trudging through the landscape of his rambles, Coleridge filled his notebooks with reference to and drawings of geometric figures. The question arises: Given his fascination with the uncultivated, irregular wild hills and rivers of his rambles, why would he utilize the fixed, abstracted geometric idiom removed from time? This chapter addresses this seeming contradiction by suggesting that his attraction to the geometric figure in his landscape descriptions is neither perplexing nor inconsistent but rather an expression of his immersion in an environment that nurtured a geometric frame of mind and believed in a mathematical ordering of the entire universe. Beginning with his mathematical training both at Christ’s Hospital School and at the University of Cambridge, Coleridge inherited a cultural conviction that one should take Euclid seriously. Furthermore, this training sharpened his powers of attention, abstraction, and an a priori intuition. Ultimately, his attachment to a geometric perspective did not distract him from his attraction to the sensuous movements, sounds, and colors of his natural surroundings. He intertwined them both and in so doing tempered his contemporaries’ way of thinking that separated the two modes of perception.
Chapter 4. Ars Poetica
This book, having concentrated on Coleridge’s prose, now wonders what remnants of Coleridge’s sensitivity to the rhythm of his steps as well as to his lineal and geometric orientation exist in his nature poetry. To begin with, this chapter focuses on how the imprint of his feet moving through a landscape significantly contributed to the ways in which he shaped the contour of his nature poems and bestowed on them a feeling of immediacy. These poems also demonstrate his keen sensitivity to the lines of motion that run through and diagram the landscape he describes in his notebooks. Also Coleridge often paid attention to his understanding of the geometric figure. This chapter turns to “Frost at Midnight” and to “This LimeTree Bower My Prison” to illustrate how the circular and triangular forms ultimately shape and unite what initially seem disconnected to create a sense of the whole. The chapter ends by recognizing, however, that the topography of Coleridge’s nature poetry is not just determined by the geometric outline of its structure but rather finds its vibrancy in the selection of sensual details. Though alert to abstract geometric figures, Coleridge’s nature poetry primarily grounds itself within the realm of his physical contact with the earth.
Chapter 5. Youth and Age
Coleridge and the Shifting Paradigm of Geometric Thought
As Coleridge aged, his prose no longer resonates with the animated descriptions of his rambling but, instead, dwells even more on working out his thoughts concerning social and political problems and the dynamics of human relations, as well as the intricacies of religious and philosophical thought. Throughout his indebtedness to the geometric idiom remains evident. However, Euclid’s hold on England’s spatial imagination was shifting. To many, such as Charles Dodgson, he was still important, but this orientation was not without its challenges, especially on the Continent, where theoretical mathematicians were exploring alternate ways of regarding one’s surroundings. The chapter closes by suggesting that Coleridge, though still basically indebted to Euclidean thought, did unwittingly and occasionally anticipate the challenges to Euclidean thought and the ensuing paradigm shifts.
Afterword — An Organic Geometry
The book concludes by suggesting that the geometric figure, in Coleridge’s hands, changes character and begins to exhibit organic qualities so that it becomes a living, growing being. Coleridge occasionally substitutes his own geometry and embraces a wild geometry that rivals the longestablished school of Euclidean thought. In this way, he obliquely joins the company of those who rivaled the authority of Euclid’s system.
Chapter 1. Coleridge Walks
The Measure of the Landscape
The first chapter describes the rough and tumble of Coleridge’s rambles between 1794 and 1804. The chapter opens by placing these excursions within a culture of walking. It depicts his propensity to be his own pathmaker rather than follow either the directives of the picturesque guides or the assigned routes of maps. Entries in his pocket notebooks reveal Coleridge’s understanding of a landscape based both upon what his eyes could see and what his feet could register. In many respects, he becomes a surveyor who measures the terrain with his boots. Often modeling his understanding of a landscape on the spirit of geometric exercises, Coleridge measured and counted his paces over a portion of ground in order to observe its lines and angles.
Chapter 2. Lines of Motion
When Coleridge trod through his surroundings, he was exceptionally alert to the tangible lines that run through and add character to a landscape. He visually traced their presence in the areas through which he rambled and attended to what he termed a landscape’s “lines of motion.” Throughout his early notebook entries, Coleridge plotted these lines to create diagrammatic sketches that recall the geometric idiom. Participating in a diagrammatic culture, Coleridge liked to capture the defining lines of a place and integrate them into his verbal descriptions. Throughout these entries, there lurks his training in Euclidean geometry. Far more than in the work of his fellow poets and writers, this background is very much at play in Coleridge’s landscape descriptions.
Chapter 3. A Geometric Frame of Mind
While trudging through the landscape of his rambles, Coleridge filled his notebooks with reference to and drawings of geometric figures. The question arises: Given his fascination with the uncultivated, irregular wild hills and rivers of his rambles, why would he utilize the fixed, abstracted geometric idiom removed from time? This chapter addresses this seeming contradiction by suggesting that his attraction to the geometric figure in his landscape descriptions is neither perplexing nor inconsistent but rather an expression of his immersion in an environment that nurtured a geometric frame of mind and believed in a mathematical ordering of the entire universe. Beginning with his mathematical training both at Christ’s Hospital School and at the University of Cambridge, Coleridge inherited a cultural conviction that one should take Euclid seriously. Furthermore, this training sharpened his powers of attention, abstraction, and an a priori intuition. Ultimately, his attachment to a geometric perspective did not distract him from his attraction to the sensuous movements, sounds, and colors of his natural surroundings. He intertwined them both and in so doing tempered his contemporaries’ way of thinking that separated the two modes of perception.
Chapter 4. Ars Poetica
This book, having concentrated on Coleridge’s prose, now wonders what remnants of Coleridge’s sensitivity to the rhythm of his steps as well as to his lineal and geometric orientation exist in his nature poetry. To begin with, this chapter focuses on how the imprint of his feet moving through a landscape significantly contributed to the ways in which he shaped the contour of his nature poems and bestowed on them a feeling of immediacy. These poems also demonstrate his keen sensitivity to the lines of motion that run through and diagram the landscape he describes in his notebooks. Also Coleridge often paid attention to his understanding of the geometric figure. This chapter turns to “Frost at Midnight” and to “This LimeTree Bower My Prison” to illustrate how the circular and triangular forms ultimately shape and unite what initially seem disconnected to create a sense of the whole. The chapter ends by recognizing, however, that the topography of Coleridge’s nature poetry is not just determined by the geometric outline of its structure but rather finds its vibrancy in the selection of sensual details. Though alert to abstract geometric figures, Coleridge’s nature poetry primarily grounds itself within the realm of his physical contact with the earth.
Chapter 5. Youth and Age
Coleridge and the Shifting Paradigm of Geometric Thought
As Coleridge aged, his prose no longer resonates with the animated descriptions of his rambling but, instead, dwells even more on working out his thoughts concerning social and political problems and the dynamics of human relations, as well as the intricacies of religious and philosophical thought. Throughout his indebtedness to the geometric idiom remains evident. However, Euclid’s hold on England’s spatial imagination was shifting. To many, such as Charles Dodgson, he was still important, but this orientation was not without its challenges, especially on the Continent, where theoretical mathematicians were exploring alternate ways of regarding one’s surroundings. The chapter closes by suggesting that Coleridge, though still basically indebted to Euclidean thought, did unwittingly and occasionally anticipate the challenges to Euclidean thought and the ensuing paradigm shifts.
Afterword — An Organic Geometry
The book concludes by suggesting that the geometric figure, in Coleridge’s hands, changes character and begins to exhibit organic qualities so that it becomes a living, growing being. Coleridge occasionally substitutes his own geometry and embraces a wild geometry that rivals the longestablished school of Euclidean thought. In this way, he obliquely joins the company of those who rivaled the authority of Euclid’s system.