As previous chapters have indicated, the common law has developed a consistent set of elements-duty, breach, causation, and damages-that plaintiffs must prove in order to recover in a negligence action. This chapter addresses basic aspects of the very difficult-and fascinating-third element, causation. The next chapter addresses several complex causation issues frequently encountered in the Torts course.
Causation is a profound problem. We could think about it for years and perhaps at the end be little closer to understanding it. Yet one of the majesties of the law is that it must answer the unanswerable: It must decide, today, between plaintiff and defendant, and lacks the luxury of indefinite speculation. Consequently, judges must settle for some working approaches to thorny problems like causation, approaches that are no doubt imperfect, perhaps not even fully intellectually consistent, and always subject to refinement and eventual change.
Although causation is a complex problem, fundamental fairness obviously requires that a defendant be held liable only for injuries he actually caused. If Jones, an electrician, wires Smith’s house, and leaves exposed wires in the wall, which cause a spark and burn down the house, Smith’s loss is a direct result of Jones’s negligence. It would not have happened if Jones had been careful, and it did happen because Jones wasn’t careful. It seems fair to shift the loss from the blameless Smith to the careless Jones. However, if the house burns down because Smith’s toddler starts the fire, Jones did not cause the harm and should not pay, even if he was negligent in wiring the house.
To assure that liability will only be imposed where the plaintiff’s loss is fairly attributable to the defendant’s conduct, courts have developed two causation requirements, causation in fact and proximate or legal causation. Cause in fact, the subject of this chapter, requires that, as a factual matter, the defendant’s act contributed to producing the plaintiff’s injury. Proximate causation, considered in Chapter 12, deals with limits on liability for remote or unexpected consequences of tortious conduct.
It is often quite clear from the events themselves that the defendant’s negligence was the cause in fact of an injury. Suppose, for example, that Wright drops a sheet of plywood from a building onto Sullivan’s car, obscuring her ability to see the road, and she crashes into a parked car. There is little doubt that Wright’s negligence “caused” the accident. Sullivan will doubtless testify that she swerved off the road because the plywood obscured her view. The accident would not have occurred otherwise. Similarly, if Darrow, a lawyer, draws a will for a client and fails to include one of the intended beneficiaries, it is clear that this omission is the cause in fact of the beneficiary’s inability to take under the will. Common sense tells us that the problem happened because the beneficiary was left out, and would not have happened if she had been included. We would all accept that Darrow’s mistake “caused” the beneficiary’s damages, and so would any court.