Abstract

In a radical new account of "causation" in the Law, I explain that "causation" is troublesome for lawyers because it is a labile term ordinary people use to express diverse information about the world. Though clarity would be promoted if we used the term "causation" to refer to the information yielded by only one type of inquiry, in the past lawyers have used the term to refer to more than one type of enquiry, while philosophers often have not specified an inquiry. I argue that the most useful inquiry for legal purposes is one that compares the actual world of a particular phenomenon (such as the world as it is following a breach of contract or a breach of a duty of care) with a hypothetical world (such as a world in which, inter alia, there had been no breach) and thereby determines, in the context of that comparison, the role that a specified factor (such as that breach) played, if any, in the existence of the actual phenomenon. {It is convenient to separate three forms of such a role of "involvement": necessity, duplicate necessity and contribution, though contribution subsumes the others.} We can then use our knowledge of the physical laws of nature, evidence of behaviour and so on to distinguish involved factors from factors that are merely "associated" with that phenomenon by a relation of constant conjunction: a determination that can be done objectively. I argue that lawyers should unequivocally choose "involvement" as the one and only interrogation that underlies and gives meaning to their use of causal terminology - in other words, lawyers should cease describing other determinations in causal terms such as the "proximate cause" question of how far down the stream of consequences of breach a defendant's liability should extend. This choice would improve the Law because (a) it promotes clarity and avoids ambiguity; (b) it promotes the clear identification of normative issues and provides a more transparent distribution of issues between "causation" and other analytical elements within legal analysis; and (c) it best serves the Law's very wide range of purposes. Part 1 of this article sets out the above argument. Part II sketches the approach of others to the issue of "causation in the Law" including the approaches of the legal realist Leon Green, the linguistic analysts Hart and Honore, the corrective justice theorist Michael Moore, the legal economist Guido Calabresi and the "new realist" Richard Wright.