Law of Wrongdoing in UK Law

You must take reasonable care to avoid acts or omissions which you can reasonably foresee would be likely to injure your neighbour. The answer seems to be 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 which are called in question.

This dictum may be read as expressing the general idea that the voluntary act of another, independent of the defender's fault, is regarded as a novus actus interveniens which, to use the old metaphor, "breaks the chain of causation." But it also expresses a general perception that we ought not to be held responsible in law for the deliberate wrongdoing of others.

I wish to emphasise that I do not think that the problem in these cases can be solved simply through the mechanism of foreseeability. When a duty is cast upon a person to take precautions against the wrongdoing of third parties, the ordinary standard of foreseeability applies; and so the possibility of such wrongdoing does not have to be very great before liability is imposed.

These cases shew that, where human action forms one of the links between the original wrongdoing of the defendant and the loss suffered by the plaintiff, that action must at least have been something very likely to happen if it is not to be regarded as novus actus interveniens breaking the chain of causation. But if the intervening action was likely to happen I do not think it can matter whether that action was innocent or tortious or criminal.

This argument is based upon the sound intuition that there is a difference between protecting people against harm caused to them by third parties and protecting them against harm which they inflict upon themselves. This philosophy expresses itself in the fact that duties to safeguard from harm deliberately caused by others are unusual and a duty to protect a person of full understanding from causing harm to himself is very rare indeed.

He said (Salmond on Torts, 1st ed, pp 83-84) that "a master … is liable even for acts which he has not authorised, provided they are so connected with acts which he has authorised, that they may rightly be regarded as modes - although improper modes - of doing them" (my emphasis): see the citation of Salmond with approval in Canadian Pacific Railway Co v Lockhart [1942] AC 591, 599 (Salmond on Torts, 9th ed, p 95) and in Racz v Home Office [1994] 2 AC 45, 53 (Salmond and Heuston, Laws of Tort, 19th ed (1987), pp 521-522; 20th ed (1992), p 457).

It remains, however, to consider how vicarious liability for intentional wrongdoing fits in with Salmond's formulation. The answer is that it does not cope ideally with such cases. It must, however, be remembered that the great tort writer did not attempt to enunciate precise propositions of law on vicarious liability. In reality it is simply a practical test serving as a dividing line between cases where it is or is not just to impose vicarious liability.