Proximate Cause

In a legal sense, the term proximate cause refers to a thing that happened to cause something else to occur. This is usually brought up when something has gone wrong, such as an automobile accident in which someone was injured, and refers to the non-injured party’s legal responsibility for the event. Examples of proximate cause are often found in personal injury cases, and other civil lawsuit cases; but this plays an important role in many criminal cases as well. To explore this concept, consider the following proximate cause definition.

Definition of Proximate Cause


  1. That which causes a negative event, such as an injury.

Origin of Proximate

1590-1600       Latin    proximatus (near, or approach)

What is Proximate Cause

Proximate cause is an act, whether intentional or negligent, that is determined to have caused someone else’s damages, injury, or suffering. It is important that courts establish proximate cause in personal injury cases because not everyone nor everything that causes an injury can be held legally liable.

Suppose a driver loses control of his car after slipping on a patch of wet leaves and crashes into another car, injuring its driver. The leaves are considered the “but-for” in this situation, meaning that “but for” the leaves, the crash would not have occurred, and the driver would not have been hurt. However, this is not an example of proximate cause because, even though the leaves were the catalyst for the accident, they cannot be sued in a court of law, nor can they be required to pay for the damages they caused.

A legal example of the “but for” rule being applied can be found in a 1910 case in the United Kingdom, in which a man put poison in his mother’s glass of milk, with the intent of killing her. The mother took a few sips of the poisoned milk, then went to bed – she never woke up. Upon autopsy, the coroner determined that the mother had died in her sleep of a heart attack, not from the poison. This meant that the poisoning was not the proximate cause of the woman’s death, and so the man could not be held criminally liable for her death.

Would the mother have died “but for” her son poisoning her milk? Yes, she would have died anyway – her son’s poisoning of the milk had nothing to do with her death; it was simply coincidence. However, if a similar case were to be heard today, the man could still be charged with attempted murder. Although his mother did not die as a result of his actions, he still intended to kill her when he poisoned her glass of milk.

Foreseeability of Harm

Even in what may be considered an accident, a party may be held liability if the harm or injury was foreseeable, or a reasonably possible result. This means that proximate cause can be linked if a reasonable person would have foreseen the harmful consequences, and taken action to prevent them. There are other circumstances that may be considered by the court in foreseeability of harm, such as the type of harm, the manner of harm, and the severity of harm.


Causation is the ability of one variable to affect another; in fact, the first variable may actually cause the second variable to exist. Correlation, which is a relationship or link between two facts, is determined by studies, and comparing statistics. It implies that one thing always, or sometimes, happens when some other thing happens, or is present.

For example:

A local college group has undertaken a study, hoping to discover why all of the golden ducks seem to be leaving the area on weekends. The group discovers that Roger always goes boating at Star Lake on Saturday mornings. There is a correlation between these two facts: (1) the ducks leave on the weekend, and (2) Roger goes fishing on the weekend. Does this mean that Roger’s actions have caused the ducks to leave?

Another example that proves that correlation does not imply causation can be found in windmills and wind speed. It could be assumed that windmill rotation causes wind, and that the faster the windmill rotates, the more wind there is (causation), but this is actually not true. Because wind has existed long before windmills were invented, one can reasonably conclude that wind does not need a windmill in order to exist. Windmills, on the other hand, do not work without wind. It is true, however, that the blowing wind causes windmills to turn.

Another example of correlation not implying causation is the 2007 report by Monash University Accident Research Centre, which found a link between the cars in the high-visibility spectrum, including white and yellow, were involved in fewer daytime accidents than cars in dark colors.

This study may be interpreted to mean that yellow cars are safer, and that if someone buys a yellow car, then he has less of a chance of ending up in an accident. However, this does not prove that yellow cars are safer per se, only that, by chance, fewer yellow cars have been involved in traffic accidents.

For example:

Sally, driving her yellow car arrives at work on time, without incident. Denise, driving her dark blue car, is hit by a distracted driver on her way to work. Even accepting the fact that fewer yellow cars are involved in accidents, there is no evidence to assume that the dark color of Denise’s car caused her accident. In other words, the color of the car is not proximate cause for the accident.

Types of Causation

In a legal case, causation is essentially an investigation into whether or not the defendant’s actions (or lack of action) caused another person to be harmed or damaged. There are two kinds of causation in cases dealing with criminal liability: factual causation and legal causation.

Factual causation relies on the “but for” test in order to establish whether or not causation exists. Factual causation requires only an answer to one question: “But for the defendant’s actions, would the harm have occurred?” If the answer is No, there is factual causation. In many cases, this type of causation is not enough. The plaintiff must prove legal causation.

Legal causation requires the plaintiff to prove that his injury or harm was caused by the defendant’s actions directly. This is because factual causation can be complicated. For instance, had Tom’s bus been running on time, he would not have been crossing that intersection at that time, which caused the car to swerve and hit another car. Can legal blame be placed on Tom for simply being in a place, distracting the driver? Or can the bus line be held legally liable, claiming that, “but for” the fact that the bus was running late, Tom would not have been at that place, at that time?

Proximate Cause Example on the Long Island Railroad

An example of proximate cause being confirmed in a factual causation case can be found in Palsgraf v. Long Island Railroad. In 1927, the Plaintiff, Mrs. Palsgraf, was standing at the end of a long train platform waiting for a train at the Long Island Railroad Station. On the other end of the same platform, a man raced to board a departing train. As the train was already moving, the man jumped onboard but, lost his balance. Railroad employees, both on the train and on the platform, pushed and pulled at the man, to help him get on the train.

As it turns out, the man was carrying a package of fireworks at the time, and as the railroad workers helped him, the package fell out of his arms, and exploded when it hit the ground. The noise of the exploding fireworks startled the crowd on the platform, causing one person to tip over a set of scales, which landed on Mrs. Palsgraf, injuring her. Mrs. Palsgraf sued the railroad, claiming that the workers were at fault for her injury, by being negligent in their handling of the man who was clearly holding a package of fireworks.

The Court found in favor of the railroad, ruling that there was no proximate cause in the railroad workers’ actions. The railroad workers could not have possibly predicted, or foreseen, that any passerby, much less Mrs. Palsgraf in particular, would be hurt as a result of how they helped another train passenger. Without proximate cause having been established, Mrs. Palsgraf could not hold the railroad liable for negligence.

The “Harm within the Risk” Rule

Mrs. Palsgraf’s case offers another example in determining proximate cause, as the court considered the “harm within the risk” test, which is the strictest test of causation that the courts can administer. The harm within the risk test considers first whether there was a class, or group of people that could foreseeably been harmed by the defendant’s actions.

For instance, could the railroad workers have known that pedestrians on the platform may have been harmed by their actions? If the answer to that questions is “yes,” then does the victim, in this case Mrs. Palsgraf, belong to that class of people? As she was a pedestrian on the platform, that answer is also “yes.”

Under the harm within the risk rule, even though the railroad workers could not have known that Mrs. Palsgraf, in particular, could be harmed by their seemingly helpful antics, she was in a set of people put at risk. This test is no longer in widespread use, as it considers only fault and liability – without taking into account actual causation. Although the workers’ actions accidentally resulted in the bag full of fireworks being dropped, they had no way of knowing something dangerous was in the package, and they acted in an attempt to keep the passenger from getting hurt.

Another Example of Harm within the Risk

Consider what might occur had the railroad workers in the Palsgraf incident had instead been throwing an un-ticketed passenger off the train, tossing his luggage onto the platform after him. The passenger’s trunk bounces sideways, and slams into a pedestrian’s shins, knocking him over, and causing serious injury. In this example, proximate cause does exist, as the workers could reasonably foresee that someone might be hurt by flying bodies or luggage, so their actions were negligent.

What if another passenger was trying to step up onto another train when this accident happened. Being distracted, he slips off the steps and breaks his leg. Can the railroad workers be held liable for this man’s injuries as well? If the court is using the harm within the risk rule, they cannot, as the rule allows causation to be made in a straight line, so to speak. This method completely ignores the “but for” test. It never addresses “but for” the railroad employees’ actions in helping the package-carrying passenger, the man who slipped off the stair wouldn’t have been injured.

Related Legal Terms and Issues

  • Civil Lawsuit – A lawsuit brought about in court when one person claims to have suffered a loss due to the actions of another person.
  • Liability – Responsible by law; to be held legally answerable for an act or omission.
  • Negligence – Failure to exercise a degree of care that would be taken by another reasonable person in the same circumstances.