Definition
Duty to minimize loss.
Injured party must take reasonable steps to reduce loss.
Etymology & Origin
From Latin 'mitigare' (to soften, to make mild, to soothe), from 'mitis' (mild, gentle, soft) + 'agere' (to drive, to do). To mitigate is, etymologically, to 'make mild' — to reduce the severity or extent of something. In damages law, mitigation means reducing the extent of the loss suffered. The doctrine imposes on the injured party a duty to take reasonable steps to keep the loss as small as practicable.
Full Legal Analysis
Mitigation of Damages: The Duty to Minimise Loss
When a contract is broken or a tort committed, the law requires the injured party to do more than simply sit back and watch the loss accumulate. The doctrine of mitigation of damages imposes a duty — not a formal obligation enforceable by suit, but a principle that limits the recoverable sum — to take all reasonable steps to reduce the loss flowing from the wrong. Loss that the claimant could reasonably have avoided, but did not, falls on the claimant and cannot be recovered from the defendant.
The Measure of Reasonableness
The duty is to take reasonable steps, not heroic ones. The claimant is not required to undertake extraordinary efforts, to incur disproportionate expense, or to compromise their own legitimate interests in order to minimise the defendant's liability. What is required is the sort of prudent, sensible action that a reasonable person in the claimant's position would take to limit their own loss — seeking medical treatment for an injury, seeking alternative employment after a wrongful dismissal, reselling rejected goods to limit the loss. The reasonableness is assessed in the circumstances known to the claimant at the time, not with the benefit of hindsight.
Two Branches of the Doctrine
The doctrine operates in two related ways. First, the claimant cannot recover for loss that could have been avoided by reasonable action — if the claimant unreasonably refused medical treatment and the injury worsened, the additional damage is not recoverable. Second, where the claimant does take reasonable mitigating steps, any expense or loss incurred in doing so is recoverable from the defendant as part of the damages — the cost of obtaining substitute performance, the expense of mitigating measures, the loss sustained in a reasonable cover transaction. The burden of showing that the claimant failed to mitigate lies on the defendant who raises the point. The doctrine reflects the law's insistence that damages serve compensation, not punishment: the claimant is made whole for the loss that the wrong caused, but not for loss the claimant could sensibly have prevented.
“The wrongdoer must answer for the harm done, but the wronged must not let the harm grow. The doctrine of mitigation is the law's refusal to underwrite passivity in the face of loss — its insistence that the injured party act, reasonably and prudently, to keep the damage within bounds. What is reasonably avoidable is not recoverable; what is reasonably spent in avoiding is.”
