‘It is never reasonable to impose liability in negligence without establishing that the
defendant’s breach caused the claimant’s loss, if only because, as the case law shows,
exceptions to the “but for” rule cannot be kept under control.’
Discuss.
The statement above seems to suggest that the only way to establish causation is the ‘but for
test’ and thus assumes that exceptions to the rule are innately separate. In reality, these
additional tests have been formulated to modify or supplement the test where it fails, either
practically or ideologically. It is unreasonable to argue that but-for (factual) causation is the only
reasonable test for causation when the impotence of the test itself has necessitated the creation
of the exceptions the assertion criticises. Although the test is largely effective, there will always
be cases where the but-for test produces an unreasonable or unfair result. Where these
exceptions arise however, the courts are, arguably, indeed unreasonable and inconsistent in the
way they find (legal) causation - a more principled modus operandi founded in the fundamentals
of tort law would therefore be welcome. Dissenting judgements in negligence cases where there
are multiple causes of damage, ‘loss of a chance’ or ‘coincidence’ seem to support this
approach - following the principle that negligent tortfeasors should compensate proportionate to
the loss incurred by the claimant.
Generally, the but-for test is sufficient for establishing causation1. In fact patterns such as where
D poisons V, it is easy to apply the test and attain the correct result: but for A’s poisoning, B
would not have died. Similarly, in cases where there is no causal link between the tort and the
harm inflicted, for example where D, a doctor, negligently treats V (who has been fatally
poisoned), there is no liability under the test (as V will die regardless of D’s actions): but for D’s
negligent conduct V would still be dead.
Conversely, in cases where there are multiple causes, the but-for test is less competent. To this
end, the courts have ruled that a negligent defendant can be held liable if it can be proved that
their tort a) materially contributed to the damage2, b) materially contributed to the state of affairs
that triggered the damage3 or c) materially increased the risk of the damage occurring4 despite
the fact that but-for causation cannot be proved. The rationale according to the House of Lords
in Fairchild is two-fold: fairness dictates that the claimants be remedied and it is necessary to
sanction a breach of duty of care.
This ostensibly complies with the governing principles of tort law itself. Where this approach
encounters difficulty, however, is in awarding damages. In Bonnington, Mcghee and Fairchild,
the courts held that the defendants were liable in full for their negligent behaviour, while in
Barker and Holtby, the claimants were only allowed to recover proportionally for the damage
1
Barnett v Chelsea & Kensington Hospital [1969] 1 QB 428; Cork v Kirby MacLean Ltd [1952] 2
All ER 402
2
Bonnington Castings v Wardlaw [1956] AC 613
3
Williams v Bermuda Hospital [2016] UKPC 4
4
McGhee v National Coal Board [1973] 1 WLR 1
defendant’s breach caused the claimant’s loss, if only because, as the case law shows,
exceptions to the “but for” rule cannot be kept under control.’
Discuss.
The statement above seems to suggest that the only way to establish causation is the ‘but for
test’ and thus assumes that exceptions to the rule are innately separate. In reality, these
additional tests have been formulated to modify or supplement the test where it fails, either
practically or ideologically. It is unreasonable to argue that but-for (factual) causation is the only
reasonable test for causation when the impotence of the test itself has necessitated the creation
of the exceptions the assertion criticises. Although the test is largely effective, there will always
be cases where the but-for test produces an unreasonable or unfair result. Where these
exceptions arise however, the courts are, arguably, indeed unreasonable and inconsistent in the
way they find (legal) causation - a more principled modus operandi founded in the fundamentals
of tort law would therefore be welcome. Dissenting judgements in negligence cases where there
are multiple causes of damage, ‘loss of a chance’ or ‘coincidence’ seem to support this
approach - following the principle that negligent tortfeasors should compensate proportionate to
the loss incurred by the claimant.
Generally, the but-for test is sufficient for establishing causation1. In fact patterns such as where
D poisons V, it is easy to apply the test and attain the correct result: but for A’s poisoning, B
would not have died. Similarly, in cases where there is no causal link between the tort and the
harm inflicted, for example where D, a doctor, negligently treats V (who has been fatally
poisoned), there is no liability under the test (as V will die regardless of D’s actions): but for D’s
negligent conduct V would still be dead.
Conversely, in cases where there are multiple causes, the but-for test is less competent. To this
end, the courts have ruled that a negligent defendant can be held liable if it can be proved that
their tort a) materially contributed to the damage2, b) materially contributed to the state of affairs
that triggered the damage3 or c) materially increased the risk of the damage occurring4 despite
the fact that but-for causation cannot be proved. The rationale according to the House of Lords
in Fairchild is two-fold: fairness dictates that the claimants be remedied and it is necessary to
sanction a breach of duty of care.
This ostensibly complies with the governing principles of tort law itself. Where this approach
encounters difficulty, however, is in awarding damages. In Bonnington, Mcghee and Fairchild,
the courts held that the defendants were liable in full for their negligent behaviour, while in
Barker and Holtby, the claimants were only allowed to recover proportionally for the damage
1
Barnett v Chelsea & Kensington Hospital [1969] 1 QB 428; Cork v Kirby MacLean Ltd [1952] 2
All ER 402
2
Bonnington Castings v Wardlaw [1956] AC 613
3
Williams v Bermuda Hospital [2016] UKPC 4
4
McGhee v National Coal Board [1973] 1 WLR 1
