I am trying to determine the principled limits, if any, on when a person may be held financially liable for damage to another ("the victim"). I'm specifically interested in the case when damage is not reasonably foreseeable, and the person's mental state is good (that is, he is not trying to perform any bad act). As I understand it, if the victim has a strange and rare medical condition where he bleeds if touched even slightly, the person is still liable for damage inflicted on the victim, even if the consequences of brushing up against him could not have been known by the person.

There are various defenses against liability, such as contribution on the victim's part to damage, or lack of factual causation. I assume that the victim did not contribute to his problem, and an act (including omission) of the person did cause the damage. Is it ever a defense to argue "it was just an accident"? I'm looking for general legal principles, not the willingness of a particular judge or jury to overlook causation of damage in a particular case. Relevant citations would be especially useful.

To point to additional examples of the type that I have in mind, assume I have a tree on my property, which looks entirely healthy. There is undetectable insect damage to the inside of the tree which weakened it, and in a freak wind storm (winds of 60 mph suddenly arose, in an area that is not windy and prone to severe wind storms), the tree was blown down -- striking the neighbor's house, causing damage. Am I liable?

2 Answers 2


To win a negligence claim, the plaintiff needs to prove that the defendant:

  1. had a duty to the plaintiff,
  2. breached that duty by failing to conform to the required standard of conduct (generally the standard of a reasonable person),
  3. the plaintiff must have suffered actual harm,
  4. the negligent conduct was, in law, the cause of that harm, and
  5. that harm was foreseeable.

If they fail to prove any one of the limbs, the claim fails entirely.

The eggshell skull principle which is what you are referring to goes to the amount of damage (and damages) that happens: not to if there is negligence in the first place.

The foundation case in the modern law of negligence is Donoghue v Stevenson:

the facts involved Mrs Donoghue drinking a bottle of ginger beer in a café in Paisley, Renfrewshire. A dead snail was in the bottle. She fell ill, and she sued the ginger beer manufacturer, Mr Stevenson. The House of Lords held that the manufacturer owed a duty of care to her, which was breached, because it was reasonably foreseeable that failure to ensure the product's safety would lead to harm of consumers.

Lord Atkin define neighbour (people to whom a duty is owed) as "persons who are so closely and directly affected by my act that I ought reasonably to have them in contemplation as being so affected when I am directing my mind to the acts or omissions that are called in question."

The determination of the existence of a duty is a matter of law, not facts, therefore the decision rests with the judge not the jury. However, the law needs to consider the particular facts of the relationship including the particular risk of injury which eventuated, the defendant's relationship to that risk and the nature of the damage suffered although no one factor is itself sufficient.

Of relevance to your hypothetical plaintiff is Bolton v Stone, the plaintiff was hit by a cricket ball which had been hit out of the ground; the defendants were members of the club committee. The judges held that as it was not reasonably foreseeable that a cricket ball would be hit so far, the club was not negligent. In the words of Lord Normand, "It is not the law that precautions must be taken against every peril that can be foreseen by the timorous." In essence, Stone being hit by a cricket ball was, in your words, an accident even though it was caused by the cricket club.

It is not reasonably foreseeable that brushing against a stranger in, say, a corridor would cause them harm. Therefore the act is not negligent even though, for this particular person, harm can be caused. In the absence of negligence, the eggshell skull principle is moot.

However, in circumstances where the defendant has knowledge of the plaintiff's condition, brushing against them may be negligent depending on all the surrounding circumstances.

  • Your answer seems to imply that negligence is a necessary condition for damages in the case of an accident: is that what you're saying? I edited the question to add a potentially clarifying scenario.
    – user6726
    Sep 21, 2016 at 16:51
  • It doesn't imply it - it says so explicitly. Of course, negligence is only one tort - there are others as well as contractual and statutory liabilities
    – Dale M
    Sep 21, 2016 at 23:04
  • The tree scenario is neither contractual nor negligence (set aside statutory liability which is a wild card): what other possibilities are there?
    – user6726
    Sep 22, 2016 at 0:19

The tree example is so common in Pennsylvania that the legal principles are common knowledge here: If a tree falls nobody can be blamed for its damage unless prior, credible notice was given.

I.e., the only way I can be held liable for the damage of a tree rooted on my property is if it is either obviously a hazard (e.g., already broken or falling) or else I am notified of the opinion of a professional arborist that it is an extraordinary hazard due to some real condition, and I do not take reasonable corrective measures.

Absent such prior notice, a tree falling and causing damage is a "pure accident." In fact, I am not even liable for cleaning up or removing any part of a tree that falls and lands outside my property.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .