The fusion of law and equity in common law systems was a crucial moment in the development of the modern law. In this volume leading scholars assess the significance of the fusion of law and equity from comparative, doctrinal, historical and theoretical perspectives.

What is equity? This book explores modern equity's nature, especially its facilitative character and its role in common law systems.

This is a book on “equity in the civil law tradition” from the double perspective of legal history and comparative law. It is intended not only for civil lawyers who want to better understand the role and history of equity in their own legal tradition, but also – and perhaps more saliently – for common lawyers who are curious about why the history of equity has unfolded so differently on the continent of Europe and in Latin America. The author begins with the investigation of the philosophical foundations of the Western notion of equity in the teachings of Plato and Aristotle and of how their ideas affected the works of the great Attic orators (chapter 2). He then addresses the way in which Roman law turned this notion into a legal concept of considerable practical importance (chapter 3) and how it survived the fall of Rome and was later elaborated in the Middle Ages by civilists and canonists (chapter 4). Subsequently, the author analyses how the notion of equity was dealt with in the Modern Era by legal humanists, Protestant and Catholic theologians, scholars of the usus modernus pandectarum and of Roman-Dutch law, and then by legal rationalism and the philosophers of the Enlightenment (chapter 5). He then deals with the history of equity on the continent since the fragmentation of the ius commune and the codifications of the nineteenth century and with its reception in Latin America (chapter 6). Finally, the author offers some closing remarks on the fundamental equivocalness (or relativity, as some scholars put it) of the notion of equity in the civil law tradition today (conclusion).

Quite by accident, Roman law and English law share a peculiar dual structure. In both systems, the law (ius civile, Common law) was supported, amended and corrected by a second legal source (ius honorarium, Equity) found in the jurisdiction of particular magistrates. How did this dual structure come into being in Rome and England, and how did it influence legal developments? In Law & Equity: Approaches in Roman law and Common law, seven specialists explore the origins and consequences of this interaction. The history of equity and law is treated by Willem Zwalve, Paul Brand, David Ibbetson and Mike Macnair, while John Cartwright, Hendrik Verhagen, Frits Brandsma and Willem Zwalve offer a comparative legal history on issues of substantive law.

Equity is a multi-faceted subject, an authentic crossroads of problems. The perspective of this study is, as a result, a mix of focuses, which includes: the philosophy of law, general legal theory, justice theory, the history of law, comparative law, legal dogma, etc. In this book, as in various earlier studies of the author, she uses the "three-dimensional" method, which facilitates a stratified focus in agreement with three levels: facts, norms, and values. The subject of equity has never been analysed as completely as in this work. It includes a dynamic study of the different types of equity throughout history and in the different legal systems; the concept, content, limits, functions and types of equity; the relationship between equity and related ideas, and equity in all the branches of the legal order.