## Facts

- The defendant (A), while visiting the claimant (C), experienced a severe schizophrenic episode.
- During this episode, A set himself on fire with petrol, resulting in injuries to both A and C.
- C sued A’s insurer (D) for negligence for the harm he suffered.
- The central issue was whether A’s actions, influenced by his mental state, met the legal standard of care required in negligence.

## Issues

1. Does mental impairment alter the standard of care owed in negligence?
2. Should the objective reasonable person standard be modified to account for a defendant’s mental illness?
3. Was A’s conduct, despite being influenced by his schizophrenic episode, considered negligent under the prevailing legal test?
4. How do exceptions apply when an individual’s actions are involuntary or caused by external forces?

## Decision

- The Court of Appeal held that A was negligent, as he had fallen below the standard of care required of a reasonable person, regardless of his mental impairment.
- The judgment stressed the standard of care in negligence remains objective and does not accommodate personal characteristics or mental illness.
- The court distinguished between acts influenced by a mental condition and those that are truly involuntary or caused by an external force, finding A’s conduct volitional.
- The insurer (D) was held liable for C’s injuries resulting from A’s negligent act.

## Legal Principles

- The standard of care in negligence is that of a reasonable person, applied objectively, irrespective of the defendant’s mental state.
- Mental impairments do not generally diminish the duty to act as a reasonable person would.
- Exceptions may apply if the actions were wholly involuntary or the result of an external force.
- Courts prefer a clear, objective standard to avoid subjective and complex medical inquiries into mental state.
- Contrast: In Mansfield v Weetabix [1998] 1 WLR 1263, sudden medical incapacitation without prior knowledge could lead to a different outcome, but this was distinguished in Dunnage.

## Conclusion

The decision in Dunnage v Randall & UK Insurance Ltd establishes that the standard of care in negligence remains objective, irrespective of mental impairment, except where actions are wholly involuntary. This promotes consistency and predictability in negligence law, limiting exceptions to cases involving total lack of volition.


Dunnage v Randall & UK Insurance Ltd [2015] EWCA Civ 673