Can long-established legal categories adjust to meet new fact situations? Must the case which does not fit neatly into such a category fail? Has the parallel development of common law and equity led to a fundamental lack of coherence in English law? The range of human experience coming before the courts is so wide that the legal system must inevitably organise it into separate categories with their own principles of analysis. One result of this categorisation is conflict over the applicable law when, for example, a case falls into more than one category or when a new fact situation arises. This book questions the adequacy of the law's response to issues which transcend and challenge its traditional categories and their boundaries. It draws together different instances from contract, tort, equity and property in which these boundary disputes commonly arise in English law. The common theme is that when confronting a new problem on the boundary between two categories of legal principle, a proper solution will require accurate insight and investigation into both sets of principle involved.