Torts - Cases, Principles, and Institutions Fifth Edition, 2016a

Witt & Tani, TCPI 2. Intentional Harms
plaintiff tended to show that he was a mere bystander at a riot, when he received a shot aimed at
another; and the court held that, if the defendant was justified in firing the shot at his antagonist,
he was not liable to the plaintiff, for the reason that the act of shooting was lawful under the
circumstances. Where a defendant, in a civil action like the one before us, attempts to justify on a
plea of necessary self-defense, he must satisfy the jury, not only that he acted honestly in using
force, but that his fears were reasonable under the circumstances, and also as to the
reasonableness of the means made use of. In this case, perhaps, the verdict would not have been
different, had the jury been properly instructed; but it might have been, and therefore the
judgment must be reversed.
Notes
1. Reasonable errors in self-defense. Why should innocent third parties bear the costs of
another person’s mistaken self-defense? Since at least Morris v. Platt, discussed in the
Courvoisier opinion, American courts have adopted the view that a defendant may not be held
liable for injuries caused by mistaken self-defense, so long as the mistake was reasonable. Other
legal systems, however, have allowed injured persons to hold defendants liable under these
circumstances, allocating mistake costs to the mistaken self-defender himself. The Roman law
rule, for example, provided that:
Those who do damage because they cannot otherwise defend themselves are
blameless; for all laws and all legal systems allow one to use force to defend oneself
against violence. But if in order to defend myself I throw a stone at my attacker and
I hit not him but a passerby I shall be liable under the lex Aquilia; for it is permitted
only to use force against an attacker.
1 THEODOR MOMMSEN & ALAN WATSON EDS., THE DIGEST OF JUSTINIAN 9.2.45.4, at p. 292
(1985). Today’s German law adopts a similar approach. See RAYMOND YOUNGS, ENGLISH,
FRENCH & GERMAN COMPARATIVE LAW 472-73 (2d ed. 2007). The French adopt the Courvoisier
approach. Jean Limpens, Robert M. Kruithof & Anne Meinertzhagen-Limpens, Liability for
One’s Own Act, in 11 INT’L ENCYCLOPEDIA OF COMPARATIVE L., 2-1, 2-171 (André Tunc ed.,
1983).
In the United Kingdom, the House of Lords recently indicated its inclination to adopt the
Roman law rule of strict liability for mistaken self-defense, regardless of whether the defendant’s
beliefs and actions were reasonable under the circumstances. A majority of the Lords of Appeal
in the case affirmed their agreement with the opinion of Lord Scott, who asserted that the correct
principle would be that “in order to establish the relevant necessity the defendant must establish
that there was in fact an imminent and real risk of attack.” Ashley v. Chief Constable of Sussex
Police, [2008] UKHL 25, 1 A.C. 962, para. 16-19. Because the issue was not squarely posed, the
Lords of Appeal did not decide the issue definitively.
On the other hand, the criminal law—and at least one U.S. jurisdiction’s tort law—adopts
a standard for self-defense that substantially vindicates a defendant whether the defendant’s belief
in the necessity of self-defense is reasonable or not. Under this approach, so long as the defendant
has a subjectively authentic belief in the threat of an attack, the defendant is privileged to respond
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