Tort Law — CA Study Note

01. Overview

Canadian negligence law sits at the intersection of common law tradition and distinctively Canadian constitutional and statutory contexts. Its organising spine is the tort of negligence, which requires a claimant to establish: (1) that the defendant owed a duty of care; (2) that the defendant breached the applicable standard of care; (3) that the breach caused the claimant's loss; and (4) that the loss was not too remote. Layered on top are developed bodies of doctrine governing negligent misrepresentation, pure economic loss, and vicarious liability.

The Supreme Court of Canada (SCC) consolidated the modern Canadian approach to duty of care in Cooper v Hobart, [2001] 3 SCR 537, 2001 SCC 79, adapting the English two-stage Anns test and giving it a distinctly Canadian character. Causation was subsequently rationalised in Clements v Clements, 2012 SCC 32, and psychiatric injury in Mustapha v Culligan of Canada Ltd, 2008 SCC 27. Understanding how these authorities interlock — and how they developed out of much earlier SCC decisions — is the key to answering examination questions confidently.

This note covers all major components of the syllabus: duty of care under the Anns/Cooper framework; standard of care; causation; remoteness; negligent misrepresentation; and vicarious liability. It also situates those doctrines historically and identifies the live academic debates that examiners reward candidates for engaging.

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02. Historical development

Pre-Donoghue foundations

Before the twentieth century, liability in negligence was fragmented and category-bound. Duties of care arose only within established relationships: carriers, innkeepers, surgeons, and the like. The early SCC cases reflect this pattern. In Brown v Leclerc (1893), 22 SCR 53, liability was assessed by reference to the conduct expected within a defined relational context, without recourse to any general principle. Similarly, Cottingham v Longman (1913), 48 SCR 542 proceeded on the assumption that particular trades attracted particular responsibilities, not that negligence was a unified cause of action.

Toronto Ry Co v Toms (1911), 44 SCR 268 illustrates the pre-Donoghue approach in the transport context: the carrier's liability to a passenger was analysed by reference to the specific obligations of a common carrier, not any neighbour principle. Taylor v Robertson (1901), 31 SCR 615 and Law v Hansen (1895), 25 SCR 69 confirm the same methodology — liability attached to recognised relationships and status, not to a general conception of reasonableness.

The Donoghue revolution and its Canadian reception

Donoghue v Stevenson [1932] AC 562 (JCPC on appeal from Scotland) fundamentally reorganised the common law. Lord Atkin's neighbour principle — that one must take reasonable care to avoid acts or omissions that can reasonably be foreseen to injure persons so closely and directly affected that one ought to have them in mind — provided a unifying rationale for all negligence. Canadian courts received Donoghue immediately, and it rapidly displaced the older category-based analysis.

The post-Donoghue era at the SCC is illustrated by Cook v Lewis [1951] SCR 830, where the Court grappled with causation problems arising from simultaneous negligent acts — an early signal that Canadian courts would develop their own doctrinal elaborations rather than simply following English authority.

The Anns era and the two-stage test

In Anns v Merton London Borough Council [1978] AC 728 (House of Lords), Lord Wilberforce proposed a two-stage test: first, whether there was a sufficient relationship of proximity giving rise to a prima facie duty; second, whether there were policy reasons to limit that duty. This test, though English in origin, was enthusiastically adopted by Canadian courts and became the dominant framework through the 1980s and 1990s. Lewis v Todd and McClure [1980] 2 SCR 694 shows the SCC working within a proximity-based analysis that foreshadows the Anns/Cooper synthesis.

Cooper v Hobart and the Canadian synthesis

By 2001, the SCC was ready to give the Anns test its definitive Canadian statement. In Cooper v Hobart, [2001] 3 SCR 537, 2001 SCC 79, the Court (McLachlin CJ and Major J) retained the two-stage structure but clarified that "proximity" at stage one is a legal conclusion drawn from an examination of the relationship between the parties, informed by policy — not merely a synonym for foreseeability. The categories of proximity that ground recognised duties of care (physical injury, property damage, relational economic loss, negligent misrepresentation, and so on) have a common law pedigree; novel cases must proceed through both stages.

Subsequent refinements

Mustapha v Culligan of Canada Ltd, 2008 SCC 27 refined the remoteness/psychiatric injury analysis. Clements v Clements, 2012 SCC 32 authoritatively restated the "but for" causation test, confirming that it is the default rule and narrowly confining the material-contribution-to-risk exception. Together with Cooper, these three cases form the SCC's modern negligence trilogy on which examination questions almost invariably turn.

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03. Core principles

A. Duty of care — the Anns/Cooper framework

Stage 1: Proximity and foreseeability

At the first stage the claimant must show: (a) that the defendant's act or omission could reasonably be foreseen to cause harm to the claimant; and (b) that the relationship between the parties was sufficiently proximate. If the case falls within a recognised category of proximity (e.g., manufacturer–ultimate consumer post-Donoghue, or the negligent misrepresentation category established by Hedley Byrne principles), a duty is established without further inquiry. If the relationship is novel, the court identifies the factors — physical proximity, reliance, undertaking, assumed responsibility, vulnerability — that support a finding of proximity.

Stage 2: Policy

Even where proximity and foreseeability are established, the court may negate or limit the duty for reasons of policy at the second stage. In Cooper v Hobart itself, the SCC denied a duty of care by a statutory regulator (the Registrar of Mortgage Brokers) to individual investors, reasoning at stage two that recognising such a duty would conflict with the statutory scheme and would expose the regulator to indeterminate liability — a classic Cooper stage-two negation.

The relationship between the two stages

Critically, Cooper clarifies that policy considerations enter at both stages: at stage one through the concept of proximity (which is normative, not merely factual), and at stage two as an independent check. Candidates must resist conflating the two stages.

B. Standard of care

The standard is that of the reasonable person in the defendant's position. Where the defendant professes special skill or expertise, the standard is calibrated to that skill — a medical professional, for example, is judged against the standard of a reasonably competent member of that profession. In Lewis v Canada, 2012 FC 1514, standard of care was assessed by reference to what a reasonably competent actor in the relevant institutional context would have done. In Miller v Canada, 2006 FC 1446, the Federal Court similarly applied an objective professional standard.

The calculus of negligence — drawn from the Hand formula in its Canadian reception — weighs: the probability of harm; the likely severity of that harm; the social utility of the conduct; and the burden of precautions. None of these factors is individually decisive.

C. Causation — the "but for" test

Clements v Clements, 2012 SCC 32 is the leading authority. The default rule is factual causation: the claimant must prove on the balance of probabilities that but for the defendant's negligence, the loss would not have occurred. The "but for" test must be applied in a robust, common-sense manner; scientific or statistical precision is not required.

Cook v Lewis and the exceptional approach

Where it is impossible to apply "but for" due to the structure of the causal problem — for instance, where two defendants simultaneously act negligently and either alone could have caused the harm — the court may resort to the material contribution to risk (MCR) exception. Cook v Lewis [1951] SCR 830 is the foundational Canadian authority, involving simultaneous shots from two hunters one of whom must have struck the plaintiff. The SCC in Clements confirmed that MCR is an exceptional departure, limited to cases of true impossibility of proof, not mere difficulty.

D. Remoteness

The defendant is liable only for losses of the type that were reasonably foreseeable at the time of the negligent act. Mustapha v Culligan of Canada Ltd, 2008 SCC 27 applied this principle to psychiatric injury: the defendant was not liable for Mr Mustapha's clinical phobia arising from watching contaminated water enter his water cooler, because psychiatric injury of that type and severity was not reasonably foreseeable in a person of ordinary fortitude. The "person of ordinary fortitude" is the benchmark; a claimant with unusual susceptibility takes the risk of unforeseeable damage.

E. Negligent misrepresentation

Negligent misrepresentation is an established category of proximity. The requirements, drawn from the Canadian reception of Hedley Byrne principles (recognised in Canadian common law), are: (i) an untrue statement; (ii) made negligently; (iii) by a defendant with a special skill or in a relationship where reliance was expected; (iv) the claimant's reasonable reliance; (v) resulting in detriment. Cloaks Ltd v Cooperberg and Davis [1959] SCR 785 demonstrates the SCC's early engagement with liability for misrepresentation in a commercial context.

F. Vicarious liability

Vicarious liability imposes strict liability on an employer for the torts of an employee committed in the course of employment. The key questions are: (1) the nature of the employment relationship; and (2) whether there is a sufficient connection between the employment and the tort. In Lewis v Nisbet & Auld Ltd [1934] SCR 333, the SCC addressed the scope of an employer's liability for acts of its employee, applying the "course of employment" test. The modern framing requires a strong connection — not merely opportunity — between the authorised field of activity and the wrong.

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04. Statutory framework

Canadian tort law is, at its core, judge-made common law. There is no general federal codification of private law negligence comparable to a civil code (though Quebec civil law, governed by the Civil Code of Québec, CQLR c CCQ-1991, operates entirely differently). The following statutory instruments are, however, significant in common law provinces.

Contributory negligence/apportionment legislation

Each common law province has enacted legislation converting contributory negligence from a complete bar to a proportionate apportionment of liability. The Negligence Act, RSO 1990, c N-1 (Ontario) is the archetype; analogous statutes operate across common law Canada. These statutes allow damages to be reduced in proportion to the claimant's own fault without extinguishing the claim.

Limitation periods

Provincial limitations statutes (e.g., the Limitations Act, 2002, SO 2002, c 24, Sched B, in Ontario) set the general limitation period at two years from the date the claim was discovered or ought to have been discovered, with an ultimate limitation period of fifteen years. Limitation defences are among the most frequently litigated procedural issues in tort practice.

Occupiers' liability

Most provinces have enacted occupiers' liability legislation (e.g., the Occupiers' Liability Act, RSO 1990, c O-2) that replaces the common law categories of invitee, licensee, and trespasser with a single standard of reasonable care, subject to exceptions for certain recreational users.

Crown liability

The Crown Liability and Proceedings Act, RSC 1985, c C-50 subjects the federal Crown to liability in tort, including negligence, in the same manner as a private person of full age and capacity. Lewis v Canada, 2012 FC 1514 and Miller v Canada, 2006 FC 1446 are both examples of negligence claims brought against the Crown under this framework.

The Charter and tort law

The Canadian Charter of Rights and Freedoms, Part I of the Constitution Act, 1982, being Schedule B to the Canada Act 1982 (UK), does not directly create private causes of action between citizens. However, Cooper c R [1980] 1 SCR 1149 (pre-Charter, but engaging the constitutional relationship between statutory duties and Crown liability) illustrates the intersection of public law obligations and private law remedies — a relationship that gains additional complexity post-Charter.

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05. Landmark cases

Donoghue v Stevenson [1932] AC 562

Though originating in Scotland and decided by the Judicial Committee of the Privy Council (then Canada's ultimate court of appeal), Donoghue is the foundational authority for the negligence duty of care in all common law Canadian jurisdictions. Lord Atkin's neighbour principle — reasonable foreseeability of harm to persons closely and directly affected — has been applied by the SCC in every generation of negligence jurisprudence. Its significance in Canada is not merely historical: the SCC in Cooper v Hobart explicitly traces the duty of care inquiry back to Donoghue and explains how the neighbour principle evolved through Anns into the contemporary two-stage framework.

Cook v Lewis [1951] SCR 830

Cook v Lewis remains the leading Canadian authority on the exceptional treatment of causation where "but for" is inapplicable. Two hunters fired simultaneously; the plaintiff was struck but could not identify which defendant's shot had caused the injury. The SCC held that once the plaintiff established that each defendant had been negligent and the injury was caused by one of them, the evidential burden shifted to each defendant to prove that his shot had not caused the harm. Neither could discharge that burden; both were held liable. Clements later clarified that Cook v Lewis represents the outer boundary of the causal departure doctrine, not a routine exception.

Cooper v Hobart (2001), [2001] 3 SCR 537, 2001 SCC 79

This is the cornerstone of the modern Canadian duty of care analysis. The Registrar of Mortgage Brokers suspended a broker but delayed publishing the suspension; investors continued to deal with the broker and suffered loss. The SCC held that no duty of care was owed by the Registrar to the investors. McLachlin CJ and Major J reformulated the Anns test for Canada: (i) proximity and reasonable foreseeability at stage one; (ii) policy considerations that may negative or limit the duty at stage two. The Court emphasised that proximity is a legal and normative concept — it asks whether, having regard to the entire relationship, it is just and fair to impose a duty. The decision authoritatively closes off attempts to use pure foreseeability as sufficient for duty.

Mustapha v Culligan of Canada Ltd, 2008 SCC 27

The plaintiff, while watching a Culligan technician service his home water cooler, saw dead flies fall into the water reservoir. He subsequently developed a major depressive disorder and phobia. The SCC (McLachlin CJ for a unanimous Court) held there was no liability. At the remoteness stage, the Court confirmed that a defendant is not liable for psychiatric injury unless such injury in a person of ordinary fortitude was a reasonably foreseeable consequence of the negligent act. The thin-skull rule does not assist where the claimant's type of injury was itself unforeseeable. This case is essential for understanding how foreseeability operates at both the duty and remoteness stages.

Clements v Clements, 2012 SCC 32

Mrs Clements was a passenger on a motorcycle ridden by her husband. The motorcycle was overloaded and the husband drove too fast; a nail was later discovered in the tyre. When the tyre blew out the motorcycle crashed and Mrs Clements suffered serious brain injury. She could not prove on the "but for" standard that the husband's negligence (speed and overloading) had caused the accident, since the nail might have caused the crash regardless. The SCC held that "but for" is the default test of factual causation and must be given its full rigorous application. The material contribution to risk exception is confined to cases where it is impossible — not merely difficult — to prove causation under "but for" because of the joint operation of multiple tortfeasors' negligence. The policy rationale for MCR is the avoidance of a denial of justice where the defendant's negligence has itself made proof impossible. The case is a paradigmatic exam authority.

Lewis v Todd and McClure [1980] 2 SCR 694

This case addresses the interaction between contributory negligence and apportionment in a motor vehicle context. The SCC's analysis of the respective contributions of parties to a shared accident illustrates how fault is allocated under the apportionment model, and remains instructive on how courts approach multi-party negligence.

Handley v Allardyce [1962] SCR 112

An early instance of the SCC working through occupier and relational liability, this case reflects the pre-statutory-reform approach to occupiers' duties and the distinction between categories of entrant — analysis now largely supplanted by provincial legislation but historically important to understanding the development of the standard of care.

Cloaks Ltd v Cooperberg and Davis [1959] SCR 785

This SCR decision provides an early SCC treatment of misrepresentation and commercial liability, illustrating the court's engagement with the principles that would later be systematised under the negligent misrepresentation heading.

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06. Doctrinal analysis

The architecture of Anns/Cooper — what "proximity" actually means

The most important doctrinal point in contemporary Canadian negligence law is the proper understanding of proximity at Cooper stage one. Proximity is not a factual closeness test; it is a normative, relational concept. The Court in Cooper identifies factors relevant to proximity as including: direct reliance; undertaking or assumption of responsibility; and the nature and closeness of the relationship. In a recognised category (physical injury to a plaintiff foreseeably endangered by the defendant's act), proximity is established by precedent without further inquiry. For novel cases, the analysis must be performed afresh.

The risk of confusing foreseeability with proximity is acute. Foreseeability establishes that the defendant ought to have thought about the plaintiff class — a wide and easily satisfied threshold. Proximity asks the further and more demanding question: was the relationship sufficiently close that the law should treat the defendant as having been under an obligation to the plaintiff? Cooper expressly overruled any suggestion that foreseeability alone suffices.

Stage two policy — content and critique

Stage two of Cooper asks whether, even if proximity is established, there are residual policy reasons to deny or limit the duty. The categories of policy reasoning recognised by the Court include: indeterminate liability (liability to an unlimited class); conflict with a statutory scheme; and chilling effects on socially useful conduct. In Cooper itself, both indeterminate liability (investors as an open class) and the structure of the statutory regulatory scheme were decisive at stage two.

Critics have questioned whether stage two introduces judicial subjectivity under the guise of policy analysis. Professor Peter Benson has argued (in the context of corrective justice theory) that policy reasoning at stage two is incompatible with the bilateral structure of private law obligations. The counter-view, associated with Professor Ernest Weinrib, is that negligence law is an inherently normative enterprise and that the policy inquiry at stage two simply makes explicit what was always implicit in proximity.

Causation and the MCR exception — the Clements settlement

The SCC in Clements performed an important tidying function. Prior to 2012, lower courts had sometimes applied MCR loosely to avoid harsh results in individual "but for" cases. Clements restricts MCR to cases where: (a) there are multiple defendants; (b) each was negligent; (c) each materially contributed to the risk of the plaintiff's injury; and (d) it is impossible — due to the nature of the causal problem — to prove "but for" causation. Single-defendant cases cannot invoke MCR; the impossibility must arise from the structure of the multi-tortfeasor problem, not merely from evidentiary gaps. This is doctrinally significant because it prevents MCR from swallowing the "but for" rule.

Remoteness and the ordinary fortitude standard

Mustapha consolidates the principle that the "type" of damage must be foreseeable. The ordinary fortitude standard serves as an objective check: the defendant is not responsible for psychiatric consequences that would only befall a person of unusual psychological vulnerability, even if the defendant was otherwise negligent. This must be distinguished from the thin-skull rule, which operates where the type of damage was foreseeable but the extent was greater than expected due to a pre-existing condition. In Mustapha, the type was unforeseeable; hence no liability. In a thin-skull case, the type is foreseeable and the defendant takes the plaintiff as found.

Negligent misrepresentation — reliance and undertaking

The Canadian law of negligent misrepresentation developed from Hedley Byrne principles (formally received in English law but adopted in Canada through judicial decision). The requirement of an "undertaking of responsibility" or "special relationship" between representor and representee is designed to prevent duties from arising whenever any statement is made. Commercial relationships in which one party professes expertise and the other party relies on that expertise in a transaction are paradigm cases. Cloaks Ltd v Cooperberg and Davis [1959] SCR 785 reflects the Court's early engagement with this reasoning.

Vicarious liability — the strong connection test

The modern test for vicarious liability requires a sufficiently strong connection between the employer's enterprise and the wrong done. It is not enough that employment provided mere opportunity; the enterprise must have created, materially enhanced, or been the contextual vehicle for the risk that materialised. Lewis v Nisbet & Auld Ltd [1934] SCR 333 applies the course-of-employment analysis in its earlier formulation. Contemporary cases have expanded the test, particularly in the context of sexual abuse in institutional settings, though the core framework remains the same.

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07. Debates & criticism

Is Cooper two stages or one?

A persistent academic critique is that the two-stage structure of Cooper is illusory: proximity at stage one already involves policy, and stage two invites courts to rehearse policy arguments they have already considered. Certain scholars argue this produces unpredictable outcomes in novel duty cases and may explain inconsistencies in lower court application. The SCC's response, implicit in Cooper, is that the two stages serve different functional purposes — stage one asks about the relational features of the parties' situation; stage two looks outward to systemic consequences — and that both are necessary for rigorous analysis.

The indeterminate liability problem

The indeterminate liability concern — that recognising a duty in a given context would expose defendants to liability to a vast and unpredictable class — is prominent in Cooper and in cases involving regulatory bodies, auditors, and public authorities. Critics question whether indeterminacy is a principled limitation or a judicial cost-benefit judgment dressed in doctrinal clothing. The counter-argument is that private law is concerned with bilateral relations, and that a remedy creating indeterminate obligations transcends what private law can coherently provide.

Causation: does Clements go far enough?

Some commentators argue that the Clements restriction on MCR is too severe and will produce unjust results where the structure of the harm makes "but for" impossible even in what are effectively single-defendant cases. The SCC's response is that in single-defendant cases, evidentiary problems should be addressed through the law of evidence and the standard of proof, not through a departure from the basic causal norm. This remains an open debate in Canadian tort scholarship.

Vicarious liability and institutional abuse

The expansion of vicarious liability in institutional sexual abuse cases has been controversial. The argument for expansion is that institutions that create authority relationships with vulnerable persons must bear the risk that those relationships are abused. The argument against is that vicarious liability is being stretched beyond its rationale (distributing the costs of productive activity) to perform a compensatory function that more properly belongs to direct liability or statutory schemes.

Psychiatric injury and access to justice

The ordinary fortitude standard in Mustapha has been criticised as potentially excluding recovery for people with pre-existing mental health conditions who are genuinely injured by tortious conduct. Claimants whose psychological architecture is more fragile may face the counterintuitive result that the less resilient they are, the less likely they are to recover. The doctrinal response is that the thin-skull rule is available where the type of harm is foreseeable, but critics argue the line between "type" and "extent" is manipulable.

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08. Comparative perspective

England and Wales

Canadian negligence law shares its foundational authorities with English law — Donoghue v Stevenson [1932] AC 562 and Anns v Merton London Borough Council [1978] AC 728 are English decisions adopted in Canada. However, the trajectories have diverged. The House of Lords in Murphy v Brentwood District Council [1991] 1 AC 398 overruled Anns in England and Wales, rejecting the two-stage test and reverting to an incremental approach based on established categories. Canada retained and refined Anns through Cooper v Hobart. This means that Canadian courts have a more openly policy-engaged framework than English courts, whose Caparo v Dickman [1990] 2 AC 605 three-stage test (foreseeability, proximity, fair and reasonable) also eschews the broad policy-at-stage-two structure.

Australia

The High Court of Australia also departed from Anns, preferring in Sullivan v Moody (2001) 207 CLR 562 an approach focused on coherence and consistency with existing doctrine rather than open policy reasoning. The Australian framework asks whether recognition of a duty would be "irrational, or incoherent with other legal principles," a more conservative and doctrinally immanent test than Cooper.

United States

American tort law has no single federal framework for negligence. The Restatement (Third) of Torts: Liability for Physical and Emotional Harm (2010) articulates a general duty to exercise reasonable care and uses foreseeability as the principal duty-limit, supplemented by "special rules" for categories like negligent misrepresentation and pure economic loss. The absence of a two-stage policy framework means US courts exercise judicial discretion on duty questions somewhat differently, though the practical results are often comparable.

Quebec

Quebec tort law is governed by Articles 1457–1481 of the Civil Code of Québec. Article 1457 provides a general duty not to cause injury to another through fault, with liability arising from any "unlawful" act or failure to act. There is no Anns/Cooper framework; the civilian concept of "fault" performs much of the same filtering work, but through different analytical machinery. Causation under Quebec law is assessed by the equivalence-of-conditions theory, though material contribution concepts are also recognised. Comparative analysis of Quebec and common law Canadian approaches is a sophisticated essay topic.

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09. Essay approach

Examination questions in Canadian negligence law typically take one of three forms: (a) a problem question requiring application of the Anns/Cooper stages; (b) an essay on the structure or merits of one of the elements (causation, remoteness, vicarious liability); or (c) a comparative question. The following approach is recommended.

For problem questions

Step 1 — Identify the cause of action and the type of loss. Is this physical injury, property damage, pure economic loss, psychiatric harm, or relational economic loss? The type of loss affects which proximity factors are relevant.

**Step 2 — Apply Cooper stage one.** Is this a recognised category? If yes, proximity is established on precedent. If not, identify the specific features of the relationship (reliance, undertaking, vulnerability, direct dealing) that support or undermine a finding of proximity. Address foreseeability separately and do not conflate it with proximity.

**Step 3 — Apply Cooper stage two.** Does the case raise concerns about indeterminate liability? Does it involve a regulatory or public authority whose statutory scheme would be undermined? Are there chilling-effect concerns? Be specific — vague appeals to "public policy" will not score well.

Step 4 — Standard of care. Identify the appropriate objective standard, calibrated to any relevant expertise. Apply the calculus of negligence factors if helpful.

Step 5 — Causation. Apply "but for" first (Clements). If "but for" cannot be satisfied, consider whether the MCR exception applies. Be rigorous: single-defendant cases generally cannot invoke MCR.

Step 6 — Remoteness. Apply the reasonable foreseeability of type of damage test. Consider ordinary fortitude (Mustapha) if psychiatric harm is involved. Apply thin-skull if the type is foreseeable but the extent is not.

Step 7 — Defences. Consider contributory negligence and apportionment under provincial legislation.

For essay questions

Lead with a clear thesis. Engage with the academic debate — name the competing positions and attribute them (Benson, Weinrib, Stapleton are commonly referenced). Use the SCC's own reasoning to evaluate the critique. Conclude by assessing whether the law achieves a coherent balance between competing values (individual autonomy, corrective justice, loss distribution, deterrence). Do not merely describe the doctrine; assess whether it is satisfactory.

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10. Exam traps

1. Conflating foreseeability with proximity. This is the single most common error. Cooper is explicit: foreseeability is a necessary but not sufficient condition for a duty. Proximity asks a distinct, normative question about the relationship. A claimant who is foreseeable may still fail at stage one if the relationship lacks the required closeness.

2. Treating stage two as a catch-all. Stage two policy analysis is disciplined. It is not an invitation to dismiss any claim that seems inconvenient. The policy grounds must be identified specifically — indeterminate liability, statutory conflict, chilling effects — and must be applied to the facts.

3. Misapplying the MCR exception. Do not apply MCR simply because "but for" is hard to prove. Clements requires impossibility arising from the multi-tortfeasor structure of the causal problem. A single defendant who negligently failed to keep records, making causation hard to establish, does not attract MCR.

4. Confusing thin-skull with the ordinary fortitude rule. The thin-skull rule operates at remoteness once the type of damage is foreseeable; it says the defendant takes the plaintiff as found. The ordinary fortitude rule operates earlier: it asks whether the type of damage was foreseeable at all in a person of normal resilience. Mustapha is the authority. Applying thin-skull where the type was unforeseeable is a significant doctrinal error.

5. Ignoring the two-stage structure in novel duty cases. When a question involves a novel fact pattern — a new type of defendant, a new relational context — candidates must perform both stages of Cooper and not simply assert that the defendant "ought to have foreseen" the harm. Examiners expect to see the framework applied, not shortcut.

6. Treating provincial contributory negligence statutes as common law. Contributory negligence in Canada is a matter of statute in each common law province. Candidates must note the relevant statute; the common law rule (contributory negligence as a complete bar) has been entirely displaced.

7. Importing English duty of care authorities as current Canadian law. Murphy v Brentwood and Caparo v Dickman are not Canadian authorities. The Anns test was overruled in England, not Canada. Citing Caparo as Canadian authority will lose marks.

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11. Q&A

Q1. The Registrar of a provincial securities commission discovers that a licensed investment dealer is insolvent but delays revoking the licence for two months while conducting a confidential investigation. During that period, 500 retail investors suffer losses. Do the investors have a negligence claim against the Registrar?

A: This is a close analogue to Cooper v Hobart, [2001] 3 SCR 537. At Cooper stage one, foreseeability is readily established — the Registrar would reasonably foresee that delay in revoking a licence could harm investors. Proximity is more problematic. The investors constitute a large, indeterminate class with no direct dealing or special reliance vis-à-vis the Registrar; the Registrar's duty is to the public generally, not to any particular investor. Proximity factors (undertaking, reliance, direct relationship) are accordingly weak. At stage two, the statutory scheme is a powerful consideration: imposing liability could compromise the confidential investigative process and expose the regulator to crushing liability, deterring regulatory action. On Cooper, the claim likely fails. A strong answer would note that the result might differ if investors had communicated directly with the Registrar and received specific assurances — that would introduce reliance and change the proximity analysis.

**Q2. Explain why Cook v Lewis [1951] SCR 830 remains good law after Clements v Clements, 2012 SCC 32.**

A: Clements reaffirms "but for" as the default causation test and restricts MCR to cases where proof is truly impossible due to the structure of a multi-tortfeasor problem. Cook v Lewis is precisely that type of case: two negligent defendants, one harmful outcome, and structural impossibility of proof (the plaintiff cannot know which shot hit him). Clements explicitly preserves Cook v Lewis as the paradigm for the MCR exception while insisting it remains exceptional. The critical doctrinal point is that the impossibility in Cook v Lewis flows from the defendants' combined negligent acts — each contributed equally to the risk, making individual "but for" causation logically incapable of proof. This structural feature distinguishes Cook v Lewis from cases where causation is merely difficult to prove, and explains why the SCC in Clements did not overrule it.

Q3. A company negligently installs a water filtration system in a family's home, introducing a harmless but visually repulsive brown discolouration to the water. The father, who has a pre-existing obsessive-compulsive disorder, develops severe contamination phobia and is hospitalised. Can he recover?

A: Under Mustapha v Culligan, 2008 SCC 27, the plaintiff must show that psychiatric injury of the type he suffered was a reasonably foreseeable consequence of the negligent act in a person of ordinary fortitude. The contamination of a water supply might cause annoyance, disgust, or mild distress in an ordinary person; it would not foreseeably cause hospitalisation-level psychiatric illness. The ordinary fortitude standard is not satisfied. The thin-skull rule does not assist because the type of harm — severe psychiatric injury — was itself unforeseeable, not merely the extent. Recovery is likely denied. A complete answer would also note that if the contamination were of a type capable of causing psychiatric harm in ordinary people (e.g., it were genuinely dangerous or the circumstances were especially distressing), the type-of-damage analysis might differ and thin-skull could then operate to capture the extent of the claimant's particular loss.

**Q4. What is the practical difference between the stage-one proximity inquiry and the stage-two policy inquiry in Cooper?**

A: Stage one asks whether the specific relationship between these parties — considered in its full factual context — is one in which it is appropriate to impose a legal obligation. It looks inward, at the nature of the relationship: did the defendant undertake a responsibility, did the plaintiff rely, was there a direct dealing? Stage two looks outward, at the systemic consequences of recognising a duty across the range of cases governed by the same rule: would it expose the defendant to indeterminate liability, undermine a statutory scheme, or create socially undesirable incentives? A finding of proximity at stage one does not guarantee liability; stage two may still negate the duty for systemic reasons. The distinction matters because it prevents courts from ignoring systemic consequences when analysing individual relationships, and vice versa.

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12. Further reading

Primary materials

• Cooper v Hobart, [2001] 3 SCR 537, 2001 SCC 79 — the foundational modern duty of care authority; read the full reasons of McLachlin CJ and Major J.
• Clements v Clements, 2012 SCC 32 — essential for causation; read alongside Cook v Lewis [1951] SCR 830.
• Mustapha v Culligan of Canada Ltd, 2008 SCC 27 — remoteness and psychiatric injury.
• Anns v Merton London Borough Council [1978] AC 728 — the English progenitor of the two-stage test; read for historical and comparative context.
• Donoghue v Stevenson [1932] AC 562 — Lord Atkin's neighbour principle; indispensable.

Secondary materials — texts

• Allen M Linden & Bruce Feldthusen, Canadian Tort Law (current edition, LexisNexis Canada) — the leading Canadian tort treatise; comprehensive on duty, standard of care, causation, and defences.
• Klar & Jefferies, Tort Law (current edition, Thomson Reuters Canada) — authoritative doctrinal analysis with particular depth on negligence and vicarious liability.
• Stephen GA Pitel & Nicholas S Rafferty, Conflict of Laws (2nd ed) — useful for cross-provincial and cross-border tort dimensions.

Secondary materials — articles

• Bruce Feldthusen, "The Anns/Cooper Approach to Duty of Care" in Tort Law: Challenging Orthodoxy (Hart Publishing) — traces the Canadian divergence from English duty law.
• Ernest Weinrib, "The Disintegration of Duty" (2006) 34 Hofstra L Rev 329 — influential corrective justice critique of policy-based duty analysis; engages with the Cooper framework.
• Jason Neyers, "Explaining the Unexplained: Vicarious Liability" (2005) 25 OJLS 31 — doctrinal and theoretical account of vicarious liability's foundations.

Practice resources

• Canadian Abridgment, "Torts" volumes (Thomson Reuters Canada) — digested case law on every negligence element, organised by doctrine.
• Canadian Cases on the Law of Torts (LexisNexis Canada) — reporter series covering SCC and appellate negligence decisions.