Defences to Negligence

In Tort Law, negligence occurs when a person breaches a duty of care owed to another, causing harm or damage. However, even if negligence is established, a defendant may raise certain defences to avoid or reduce liability. These defences play a crucial role in balancing justice between the claimant and the defendant. This article explores the primary defences to negligence, supported by key case law.

Contributory Negligence
Contributory negligence arises when the claimant has also acted negligently, contributing to their own harm. This defence does not absolve the defendant of liability but reduces the damages payable in proportion to the claimant's share of responsibility. The principle is codified in the Law Reform (Contributory Negligence) Act 1945, which allows courts to apportion damages. In Froom v Butcher [1976], the claimant was injured in a car accident caused by the defendant's negligence. However, the claimant was not wearing a seatbelt, which contributed to the severity of his injuries. The court reduced the damages by 25%, emphasising that contributory negligence applies where the claimant's actions exacerbate the harm.

Volenti Non Fit Injuria (Consent)
The defence of volenti non fit injuria, meaning "to a willing person, no injury is done", applies when the claimant has voluntarily accepted the risk of harm. To succeed, the defendant must show that the claimant had full knowledge of the risk and willingly agreed to it. In Smith v Baker [1891], a worker was injured by machinery at his workplace. The defendant argued that the worker had accepted the risk by continuing to work in dangerous conditions. However, the court held that mere awareness of danger does not constitute consent unless the claimant freely and voluntarily agrees to waive their rights. This case highlights the high threshold for establishing volenti.

Illegality (Ex Turpi Causa)
The doctrine of ex turpi causa non oritur actio, meaning "no action arises from a dishonorable cause", prevents claimants from recovering damages if their injury results from their own illegal actions. This defence seeks to uphold public policy by denying compensation to individuals engaged in unlawful conduct. In Ashton v Turner [1981], the claimant was injured in a car accident caused by the defendant's negligent driving. Both parties had been fleeing the scene of a burglary. The court rejected the claim, stating that allowing recovery would undermine public policy by encouraging illegal behaviour.

Necessity
The defence of necessity may apply where the defendant's actions, though negligent, were justified by the need to prevent greater harm. This defence is rarely invoked in negligence cases but may arise in emergencies where the defendant had to make difficult choices to protect public or private interests. An example can be seen in Southwark LBC v Williams [1971], where squatters argued necessity to justify occupying a house. While not a negligence case, the court emphasised that necessity is a narrow defence that requires compelling justification.

Exclusion of Liability
Defendants may attempt to limit or exclude liability for negligence through contractual clauses or notices. However, the enforceability of such exclusions is subject to statutory controls, particularly under the Unfair Contract Terms Act 1977 and the Consumer Rights Act 2015. These laws prevent defendants from excluding liability for death or personal injury caused by negligence. In White v Blackmore [1972], a man was killed during a car rally due to defective safety arrangements. The organisers relied on an exclusion clause, but the court held that the clause did not effectively protect them from liability for negligence. This case illustrates the courts' scrutiny of exclusion clauses to ensure fairness.

Act of God (Natural Events)
The defence of an act of God applies when the harm caused is the result of extraordinary natural events that could not have been foreseen or prevented. While more commonly associated with nuisance claims, it can sometimes be invoked in negligence cases. In Nichols v Marsland [1876], the defendant's artificial lakes overflowed during an unprecedented storm, causing damage to the claimant's property. The court held that the storm was an act of God, absolving the defendant of liability. This defence is rarely successful unless the event is truly exceptional and unforeseeable.

The defences to negligence reflect the effort of the courts to ensure fairness. Each defence operates under strict legal principles, often requiring the defendant to meet a high evidentiary threshold. Through the application of case law, courts ensure that liability is imposed only where it is just and equitable to do so. These defences not only protect defendants from unjust outcomes but also serve to refine the boundaries of negligence law.