Negligence claims succeed or fail on causation. A business owner may breach a duty of care in the most obvious way imaginable, but without causation linking that breach to the plaintiff's injury, the claim collapses. This fourth lesson examines how Canadian law approaches causation, why it presents unique challenges in negligence litigation, and what business operators need to understand about proving or disproving the causal chain between a breach and resulting harm.
Causation sits at the heart of negligence analysis because the law refuses to hold defendants responsible for harm they did not actually cause. This principle reflects fundamental notions of fairness that permeate Canadian tort law. A defendant who breaches their duty of care but causes no harm owes nothing in damages. Conversely, a plaintiff who suffers genuine injury but cannot trace that injury back to the defendant's breach recovers nothing. The causation requirement ensures that legal responsibility attaches only where the defendant's conduct genuinely brought about the plaintiff's loss.
Canadian courts approach causation through two distinct inquiries that serve different purposes within the negligence framework. The first inquiry, causation in fact, asks whether the defendant's breach actually caused the plaintiff's injury as a matter of physical or historical reality. The second inquiry, remoteness or legal causation, asks whether the connection between breach and injury is close enough that the law should impose liability. Both inquiries must be satisfied for a negligence claim to succeed, and both present challenges that business owners should understand.