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529US2

Unit: $U51

[09-26-01 10:31:04] PAGES PGT: OPIN

Cite as: 529 U. S. 494 (2000)

503

Opinion of the Court

Consistent with this principle, it was sometimes said that
a conspiracy claim was not an independent cause of action,
but was only the mechanism for subjecting co-conspirators
to liability when one of their member committed a tortious
act. Royster v. Baker, 365 S. W. 2d 496, 499, 500 (Mo. 1963)
(“[A]n alleged conspiracy by or agreement between the de-
fendants is not of itself actionable. Some wrongful act to
the plaintiff ’s damage must have been done by one or more
of the defendants, and the fact of a conspiracy merely bears
on the liability of the various defendants as joint tort-
feasors”). See Halberstam v. Welch, 705 F. 2d 472, 479
(CADC 1983) (“Since liability for civil conspiracy depends on
performance of some underlying tortious act, the conspiracy
is not independently actionable; rather, it is a means for es-
tablishing vicarious liability for the underlying tort”).7

7 Justice Stevens quotes from some of the cases we have cited to
suggest that the common law allowed recovery from harm caused by
any overt act in furtherance of the conspiracy. See post, at 510–511, n. 5
(dissenting opinion). However, his quotations omit pertinent language.
When read in context, it is clear that these passages refer to harm, not
from any overt act, but only from overt acts that are themselves tortious.
Compare ibid. with Adler v. Fenton, 24 How. 407, 410 (1861) (“[I]t must
be shown that the defendants have done some wrong, that is, have violated
some right of theirs . . . .
[I]n these cases the act must be tortious”);
Royster v. Baker, 365 S. W. 2d 496, 499 (Mo. 1963) (“Strictly speaking,
there has been no distinct form of writ or action of conspiracy; but the
action sounds in tort, and is of the nature of an action on the case upon
the wrong done under the conspiracy alleged. The gist of the action is
not the conspiracy, but the wrong done by acts in furtherance of the con-
spiracy” (citations and internal quotation marks omitted)); Lesperance v.
North American Aviation, Inc., 217 Cal. App. 2d 336, 345, 31 Cal. Rptr.
873, 878 (1963) (“ ‘It is well settled that a conspiracy cannot be made the
subject of a civil action unless something is done which without the con-
spiracy would give a right of action’ ”); Earp v. Detroit, 16 Mich. App. 271,
275, 167 N. W. 2d 841, 845 (1969) (“There is no civil action for conspiracy
alone.
It must be coupled with the commission of acts which damaged
the plaintiff. Recovery may be had from parties on the theory of con-
certed action as long as the elements of the separate and actionable tort
are properly proved” (citation omitted)); Halberstam v. Welch, 705 F. 2d