## Facts

- The plaintiff and defendant each owned a dog; the dogs began fighting in the owners’ presence.
- The defendant attempted to separate the dogs using a stick about four feet long, striking at the dogs as they moved.
- The plaintiff stood nearby and stepped toward the dogs as the struggle moved in his direction.
- While retreating backward with his back toward the plaintiff, the defendant raised the stick to strike the dogs and accidentally struck the plaintiff in the eye, causing serious injury.
- The plaintiff sued in trespass for assault and battery seeking damages for the injury.

## Issues

1. Whether accidental personal injury caused during a lawful act creates liability absent proof that the defendant failed to use ordinary care and prudence.
2. Whether the plaintiff bears the burden to prove the defendant’s want of due care, rather than the defendant bearing the burden to prove heightened (“extraordinary”) care or inevitability.
3. Whether the plaintiff’s lack of ordinary care bars recovery if it contributed as an efficient cause of the injury.

## Decision

- The Supreme Judicial Court of Massachusetts held that liability for an accidental blow during a lawful act depends on the defendant’s fault, measured by ordinary care and prudence under the circumstances.
- The court held that the burden of proof rests on the plaintiff to establish the defendant’s want of due care.
- The court held that if both parties failed to use ordinary care, the plaintiff cannot recover unless he proves the injury was caused wholly by the defendant and the plaintiff’s negligence did not contribute as an efficient cause.
- The court ruled the trial court’s instructions were erroneous because they effectively imposed an “extraordinary care” requirement when the defendant had no legal duty to intervene.
- Judgment for the plaintiff was reversed and a new trial was ordered.

## Legal Principles

- When a defendant engages in a lawful and proper act, accidental injury to another is not actionable without proof that the defendant failed to exercise ordinary care and prudence appropriate to the circumstances.
- “Ordinary care” is context-dependent; the factfinder must evaluate the necessity and manner of the defendant’s conduct and the surrounding risks.
- In negligence-type claims arising from accidental harm during lawful conduct, negligence is not presumed from the mere occurrence of an accident; the plaintiff must prove the defendant’s want of due care.
- Contributory negligence can bar recovery when the plaintiff’s lack of ordinary care contributes as an efficient cause of the harm, absent proof that the harm was caused wholly by the defendant.

## Conclusion

The court replaced a contact-based approach to liability in trespass with a fault-based negligence rule for accidental injuries arising from lawful conduct, placing on the plaintiff the burden to prove the defendant’s lack of ordinary care and recognizing contributory negligence as a bar where it efficiently contributes to the injury.


Brown v. Kendall, 60 Mass. (6 Cush.) 292 (Mass. 1850)