On June 29, 2012, the Supreme Court of Canada released its
decision in the case of Clements v Clements.1
The majority decision, written by Chief Justice McLachlin,
clarifies the analytical approach for determining causation in a
negligence context – specifically, when courts should
apply the traditional "but for" test versus the
"material contribution" test.
Though Clements is a motor vehicle injury case, the
Court's analysis may have widespread application to
circumstances where a plaintiff alleges loss due to the negligent
conduct of two or more defendants.
What are the potential tests for causation in negligence?
Canada's highest court confirmed that in order to
establish liability in negligence, a plaintiff must prove that a
defendant's negligent conduct was a material cause of the
loss suffered. Typically, this is accomplished using the "but
for" test, whereby the plaintiff must establish that the loss
would not have occurred absent the defendant's
