What is a mere equity?: An investigation of the nature and function of so-called ‘mere equities’

This thesis will examine the type of equitable claim known as a ‘mere equity’. The basic characteristics of a mere equity are well established. A mere equity is ‘proprietary’ in that it can be enforced against certain third parties and is capable of alienation in favour of certain third parties. Despite its proprietary flavour, however, a mere equity does not amount to an interest in any property to which it relates. The main consequence of this is that a mere equity is postponed to any interest, legal or equitable, subsequently purchased for value and without notice of the mere equity. While the core features of mere equities are settled, there is much confusion over the underlying legal nature and practical function of these claims. This confusion has produced the criticism that mere equities are an anomalous category, and brought into question whether mere equities should even exist as a juridical concept. This state of affairs is clearly unsatisfactory, especially given that mere equities are the admitted basis of a sizable body of equitable doctrines, including rescission, rectification and proprietary estoppel. This thesis aims to demystify mere equities. It will show that the existing scholarly literature has not adequately engaged with the concept of a mere equity. It will then look afresh at the primary legal materials in order to fill in the conceptual gaps. In short, the thesis will argue that a mere equity is an equitable right of action: a simple claim to pursue a particular equitable remedy against a particular defendant. A mere equity, therefore, is a right in personam—a claim binding on a small and definite class of people—albeit one which has been extended to third parties in accordance with equitable principles. The identification of these principles will be a major concern of the thesis.