Tort; Negligence; causation of harm; estimate of future harm.
Facts: Jobling, an employee of Associated Dairies, was injured as a result of the Associated Dairies' negligence. The injury (a slipped disk) made Jobling permanently unable to do anything except light work. He claimed damages from Associated Dairies for the harm, including his loss of potential earnings. Before the trial, Jobling developed an unrelated illness (myelopathy) that resulted in a permanent and total incapacity to work.
Issue: The question was whether Associated Dairies should pay damages for lost potential earnings only up to the time that the illness caused Jobling's total incapacity to work, or whether that illness and its effect should be ignored and the damages calculated over a longer period of time.
Decision: The House of Lords held that Jobling's illness and its effect should be taken into account for the purpose of assessing damages.
Reason: When damages are calculated to compensate for future losses, a court is entitled to take into account events that have actually occurred before the trial that affect the extent to which the defendant's conduct has actually caused harm to the plaintiff. In this case, the plaintiff's independently occurring illness meant that the defendant's conduct only deprived the plaintiff of the opportunity to work until that illness was contracted, and not beyond that time.