The ideal of balance and its association with what is ordered, just, and healthful remained unchanged throughout the medieval period. The central place allotted to balance in the workings of nature and society also remained unchanged. What changed within the culture of scholasticism, between approximately 1280 and 1360, was the emergence of a greatly expanded sense of what balance is and can be. In this groundbreaking history of balance, Joel Kaye reveals that this new sense of balance and its potentialities became the basis of a new model of equilibrium, shaped and shared by the most acute and innovative thinkers of the period. Through a focus on four disciplines - scholastic economic thought, political thought, medical thought, and natural philosophy - Kaye's book reveals that this new model of equilibrium opened up striking new vistas of imaginative and speculative possibility, making possible a profound re-thinking of the world and its workings.

Winner, 2017 Haskins Medal, Medieval Academy of America

Winner of the 2015 Jacques Barzun Prize in Cultural History, American Philosophical Society

'Simply stated, my enthusiasm for A History of Balance, 1250–1375 is boundless. Words such as 'transformative' and 'pathbreaking' do not adequately convey [Kaye's] accomplishment … [His] synthetic vision renders coherent vast bodies of medieval literatures that one might suspect are integral to one another, but that no one before him has demonstrated so thoroughly and powerfully. I feel confident in saying that in decades hence, scholars will still be citing and drawing upon the insights offered by [this book]. I guarantee that [it] will profoundly inform my own future research on the intellectual history of the Middle Ages.'

Cary J. Nederman Source: Renaissance Quarterly

'Through his analysis of the shifting sense of balance, Kaye opens up a fresh view on the history of ideas in the high and later Middle Ages, as well as a lens, he hopes, through which others might productively begin to examine the thought of other times and places. At every stage, the reader experiences a feeling of intellectual wonder not unlike that of a child holding up a kaleidoscope, as the 'pieces' of medieval thought fall into a new and beautiful array. A History of Balance, 1250–1375 is one of the most deeply satisfying works of intellectual history I have read in a long time.'

Laura A. Smoller Source: The American Historical Review

'It is the spirit of the works of M. Bloch and Jacques Le Goff that is found here … this magnificent work will live on as an indispensable reference. The model [of balance] now takes its place as a splendid object of historical investigation.'

Alain Boureau Source: translated from Annales: Histoire, Sciences Sociales

'… this is an exciting, deep, and detailed history of a medieval approach to understanding nature and society that achieved much before slowing down and fading in the 1370s … Kaye’s book convincingly shows that medieval models for understanding equilibrium and motion were present in medicine (traced back to Galen) before physics - and perhaps in ethics and economics even before that … This book traces the history of a large part of scholastic philosophy from 1250 to 1375 - if this is a history of balance, it is a lot more besides.'

Edith Dudley Sylla Source: Isis: A Journal of the History of Science Society

'Kaye’s synthesis in A History of Balance, 1250–1375 is a powerful and persuasive new framework in which to understand the development of medieval intellectual life.'

James Byrne Source: Early Science and Medicine

'In his intriguing and learned A History of Balance, 1250–1375, Joel Kaye lays out a bold and original account of intellectual transformation in the late Middle Ages. In impressive detail, he chronicles the formation of a model of equilibrium, or balance, in the minds and writings of late medieval thinkers. This model … gave rise to strikingly novel ideas about the self-regulating actions of the human body, commerce, and politics. His study breaks new ground in its account of the subtle interplay of experience and thought in the work of these authors - they show the influence not only of ancient texts (especially Galen and Aristotle), but also of their own everyday experiences in the large commercial cities of Europe.'

Pamela Smith - Columbia University

'Joel Kaye presents us with a masterful and beautifully crafted study of an original, hitherto unstudied topic in medieval scholastic thought that cuts through a plethora of fields of thinking. The resulting text is an inspiring account of the rise and fall of the 'new model of equilibrium or balance'. Kaye writes with admirable clarity, breadth, and subtlety, with all the skills of a first-rate intellectual historian. Historians and students will find reading this book a rewarding and stimulating task that will expose them to a complex and sophisticated argument and a major innovation to the traditional narrative of the history of medieval thought.'

Joseph Ziegler - University of Haifa, Israel

'Riveting and astonishing. With the concept of dynamic equilibrium - balance achieved through change and instability - Joel Kaye reveals the new way that thinkers came to comprehend order and its attainment. Far from emphasizing stasis or harmony, late-medieval thought is shown as understanding nature and human institutions as shifting but self-regulating systems. Never has medieval Scholastic philosophical speculation been made to appear so fascinating, and never before have tricky notions of incommensurability, geometric progression and economic regulation been explained so lucidly. A History of Balance, 1250–1375 is a deep and startling page-turner.'

Paul Freedman - Yale University, Connecticut

'Joel Kaye's study of different models of equilibrium developed by a wide range of leading thinkers in Europe in the late Middle Ages is highly stimulating. He writes interestingly, intriguingly, and clearly on ideas of balance in natural science, medicine, politics, economics, and finance, and finds many connections between them.'

David Luscombe - University of Sheffield

'By weaving together ideas from medicine, economics, politics and natural philosophy, A History of Balance, 1250–1375 uncovers historically conditioned conceptual frameworks and thus sheds new light on the history of ideas of 1250–1375.'

Christoph Flüeler - University of Fribourg

'A powerful study of a line of thought that continues to echo in our own day. For a moment in history … the free play of equal and interacting agents could determine both civil justice and the common good. Kaye offers a fascinating account of a moment in the constitution of ideas of public self-regulation and their decline.'

Harold Cook - Brown University, Rhode Island

'Kaye’s book convincingly shows that medieval models for understanding equilibrium and motion were present in medicine (traced back to Galen) before physics - and perhaps in ethics and economics even before that: witness the impressive economic writings of Peter of John Olivi.'

Edith Dudley Sylla Source: Isis

'This is a wonderful, sophisticated and extremely detailed study of equilibrium in the later Middle Ages. The scholarship is meticulous, the prose lucid and the argument convincing. Ranging between disciplines, from the history of economic thought, to medieval medical theory, to political philosophy, to analysis of illuminated manuscripts and commentary on economic and socio-cultural context, Joel Kaye’s book should be of great interest to a wide range of historians.'

H. Skoda Source: The English Historical Review