Causation in the law
Authors: Wright Richard W. 
Published: September 2018

Causal language is pervasive in the law, especially in those areas, such as contract law, tort law and criminal law, that deal with legal responsibility for the adverse consequences of voluntary and involuntary human interactions. Yet there are widely varying theories on the nature and role of causation in the law. At one extreme, the causal minimalists claim that causation plays little or no role in attributions of legal responsibility. At the opposite extreme, the causal maximalists claim that causation is the primary or sole determinant of legal responsibility. These divergent views are rooted in different conceptions of: (1) the nature or meaning of causation, (2) the relationship between causation and attributions of legal responsibility, and (3) the basic purposes of the relevant areas of law.

Much of the disagreement and confusion stems from the ambiguous usages of causal language in the law, which follow the ambiguous usages of causal language in ordinary, non-legal discourse. In both areas, causal language is sometimes used in its primary sense to refer to the content and operation of the empirical laws of nature, but at other times it is used in a more restricted normative sense to signify that one of the contributing conditions has been identified as being more important than the other conditions, in relation to some particular purpose. The relevant purpose in the law is the attribution of legal responsibility for some consequence. Thus, in legal discourse, causal language is ambiguously employed to grapple not only with the empirical issue of causal contribution but also with the normative issue of legal responsibility. The failure to use language that clearly identifies and distinguishes these two issues has generated considerable disagreement and confusion over each issue and the nature of the relationship between them.

Further disagreement and confusion have been generated by the difficulty of providing useful, comprehensive criteria for the resolution of each of these issues. The most widely used criterion for the empirical issue of causal contribution is the necessary-condition (conditio sine qua non) test. This test has been subjected to considerable criticism as being over-inclusive or under-inclusive or both, and as inviting or even requiring resort to normative policy issues to resolve what supposedly is a purely empirical issue. The deficiencies of the necessary-condition test, coupled with the difficulties encountered in trying to devise a useful alternative test that does not beg the question, have led many to conclude that there is no purely empirical concept of causation, and that there is thus no more than a minimal role for causation in the attribution of legal responsibility.

This causal-minimalist position has been especially attractive to the legal economists and the critical legal scholars, since it undermines the traditional conception of the law as an instrument of interactive justice, whereby everyone is required to avoid causing injury to the persons and property of others through interactions that fail to respect properly those others’ equal dignity and autonomy. The traditional conception, with its focus on individual autonomy, rights and causation, is inconsistent with the social-welfare maximizing theories of the legal economists and the anti-liberal, deconstructionist programme of the critical legal scholars. The members of each causal-minimalist group therefore argue that the concept of causation should be: (a) jettisoned entirely and replaced by direct resort to the social policy goals which they believe do or should determine the ultimate incidence and extent of legal responsibility; (b) redefined as being reducible to those social policy goals; or (c) retained as useful rhetoric that can be manipulated to achieve or camouflage the pursuit of those social policy goals.