Apportionment of Damages for Contributory Negligence: The Causal Potency Criterion


  • James Goudkamp Fellow and Tutor in Law, Keble College, Oxford; Associate Professor, Oxford Law Faculty; Senior Honorary Research Fellow, Faculty of Law, University of Western Australia; Professorial Fellow, School of Law, University of Wollongong; barrister, 7 King’s Bench Walk.
  • Lewis Klar QC. Professor Emeritus, University of Alberta.



The courts in several common law jurisdictions have adopted a causal potency criterion for

the purposes of apportioning damages for contributory negligence. It has recently been

suggested that Canadian courts should follow suit. This article explores the causal potency

criterion. It is argued that the criterion has been left unexplained with the result that it is an

empty concept. Moreover, no compelling justification has been offered in support of taking

causal potency into account. Accordingly, adopting the causal potency criterion would be

a retrograde step for Canadian tort law.