opinion: Mr. Justice Frankfurter
  delivered the opinion of the Court.
  William Brandhove brought this action in the United States District Court for the Northern District of California, alleging that he had been deprived of rights guaranteed by the Federal Constitution. The defendants are Jack B. Tenney and other members of a committee of the California Legislature, the Senate Fact-Finding Committee on Un-American Activities, colloquially known as the Tenney Committee. Also named as defendants are the Committee and Elmer E. Robinson, Mayor of San Francisco.
  The action is based on §§43 and 47 (3) of Title 8 of the United States Code. These sections derive from one of the statutes, passed in 1871, aimed at enforcing the Fourteenth Amendment. Act of April 20, 1871, c. 22, §§ 1, 2,17 Stat. 13. Section 43 provides:
  “Every person who, under color of any statute, ordinance, regulation, custom, or usage, of any State or Territory, subjects, or causes to be subjected, any citizen of the United States or other person within the jurisdiction thereof to the deprivation of any rights, privileges, or immunities secured by the Constitution and laws, shall be liable to the party injured in an action at law, suit in equity, or other proper proceeding for redress.” R. S. § 1979, 8 U. S. C. § 43.
  Section 47 (3) provides a civil remedy against “two or more persons” who may conspire to deprive another of constitutional rights, as therein defined.
  Reduced to its legal essentials, the complaint shows these facts. The Tenney Committee was constituted by a resolution of the California Senate on June 20, 1947. On January 28, 1949, Brandhove circulated a petition among members of the State Legislature. He alleges that it was circulated in order to persuade the Legislature not to appropriate further funds for the Committee. The petition charged that the Committee had used Brand-hove as a tool in order “to smear Congressman Franck R. Havenner as a ‘Red’ when he was a candidate for Mayor of San Francisco in 1947; and that the Republican machine in San Francisco and the campaign management of Elmer E. Robinson, Franck Havenner’s opponent, conspired with the Tenney Committee to this end.” In view of the conflict between this petition and evidence previously given by Brandhove, the Committee asked local prosecuting officials to institute criminal proceedings against him. The Committee also summoned Brandhove to appear before them at a hearing held on January 29. Testimony was there taken from the Mayor of San Francisco, allegedly a member of the conspiracy. The plaintiff appeared with counsel, but refused to give testimony. For this, he was prosecuted for contempt in the State courts. Upon the jury’s failure to return a verdict this prosecution was dropped. After Brandhove refused to testify, the Chairman quoted testimony given by Brand-hove at prior hearings. The Chairman also read into the record a statement concerning an alleged criminal record of Brandhove, a newspaper article denying the truth of his charges, and a denial by the Committee’s counsel — who was absent — that Brandhove’s charges were true.
  Brandhove alleges that the January 29 hearing “was not held for a legislative purpose,” but was designed “to intimidate and silence plaintiff and deter and prevent him from effectively exercising his constitutional rights of free speech and to petition the Legislature for redress of grievances, and also to deprive him of the equal protection of the laws, due process of law, and of the enjoyment of equal privileges and immunities as a citizen of the United States under the law, and so did intimidate, silence, deter, and prevent and deprive plaintiff.” Damages of $10,000 were asked “for legal counsel, traveling, hotel accommodations, and other matters pertaining and necessary to his defense” in the contempt proceeding arising out of the Committee hearings. The plaintiff also asked for punitive damages.
  The action was dismissed without opinion by the District Judge. The Court of Appeals for the Ninth Circuit held, however, that the complaint stated a cause of action against the Committee and its members. 183 F. 2d 121. We brought the case here because important issues are raised concerning the rights of individuals and the power of State legislatures. 340 U. S. 903.
  We are again faced with the Reconstruction legislation which caused the Court such concern in Screws v. United States, 325 U. S. 91, and in the Williams cases decided this term, ante, pp. 70, 97. But this time we do not have to wrestle with far-reaching questions of constitutionality or even of construction. We think it is clear that the legislation on which this action is founded does not impose liability on the facts before us, once they are related to the presuppositions of our political history.
  The privilege of legislators to be free from arrest or civil process for what they do or say in legislative proceedings has taproots in the Parliamentary struggles of the Sixteenth and Seventeenth Centuries. As Parliament achieved increasing independence from the Crown, its statement of the privilege grew stronger. In 1523, Sir Thomas More could make only a tentative claim. Roper, Life of Sir Thomas More, in More’s Utopia (Adams ed.) 10. In 1668, after a long and bitter struggle, Parliament finally laid the ghost of Charles I, who had prosecuted Sir John Elliot and others for “seditious” speeches in Parliament. Proceedings against Sir John Elliot, 3 How. St. Tr., 294, 332. In 1689, the Bill of Rights declared in unequivocal language: “That the Freedom of Speech, and Debates or Proceedings in Parliament, ought not to be impeached or questioned in any Court or Place out of Parliament.” 1 Wm. & Mary, Sess. 2, c. II. See Stockdale v. Hansard, 9 Ad. & El. 1, 113-114 (1839).
  Freedom of speech and action in the legislature was taken as a matter of course by those who severed the Colonies from the Crown and founded our Nation. It was deemed so essential for representatives of the people that it was written into the Articles of Confederation and later into the Constitution. Article V of the Articles of Confederation is quite close to the English Bill of Rights: “Freedom of speech and debate in Congress shall not be impeached or questioned in any court or place out of Congress . . . .” Article I, § 6, of the Constitution provides: . . for any Speech or Debate in either House, [the Senators and Representatives] shall not be questioned in any other Place.”
  The reason for the privilege is clear. It was well summarized by James Wilson, an influential member of the Committee of Detail which was responsible for the provision in the Federal Constitution. “In order to enable and encourage a representative of the public to discharge his public trust with firmness and success, it is indispensably necessary, that he should enjoy the fullest liberty of speech, and that he should be protected from the resentment of every one, however powerful, to whom the exercise of that liberty may occasion offence.” II Works of James Wilson (Andrews ed. 1896) 38. See the statement of the reason for the privilege in the Report from the Select Committee on the Official Secrets Acts (House of Commons, 1939) xiv.
  The provision in the United States Constitution was a reflection of political principles already firmly established in the States. Three State Constitutions adopted before the Federal Constitution specifically protected the privilege. The Maryland Declaration of Rights, Nov. 3, 1776, provided: “That freedom of speech, and debates or proceedings, in the legislature, ought not to be impeached in any other court or judicature.” Art. VIII. The Massachusetts Constitution of 1780 provided: “The freedom of deliberation, speech and debate, in either house of the legislature, is so essential to the rights of the people, that it cannot be the foundation of any accusation or prosecution, action, or complaint, in any other court or place whatsoever.” Part The First, Art. XXI. Chief Justice Parsons gave the following gloss to this provision in Coffin v. Coffin, 4 Mass. 1, 27 (1808):
  “These privileges are thus secured, not with the intention of protecting the members against prosecutions for their own benefit, but to support the rights of the people, by enabling their representatives to execute the functions of their office without fear of prosecutions, civil or criminal. I therefore think that the article ought not to be construed strictly, but liberally, that the full design of it may be answered. I will not confine it to delivering an opinion, uttering a speech, or haranguing in debate; but will extend it to the giving of a vote, to the making of a written report, and to every other act resulting from the nature, and in the execution, of the office; and I would define the article as securing to every member exemption from prosecution, for every thing said or done by him, as a representative, in the exercise of the functions of that office, without inquiring whether the exercise was regular according to the rules of the house, or irregular and against their rules.”
  The New Hampshire Constitution of 1784 provided: “The freedom of deliberation, speech, and debate, in either house of the legislature, is so essential to the rights of the people, that it cannot be the foundation of any action, complaint, or prosecution, in any other court or place whatsoever.” Part I, Art. XXX.
  It is significant that legislative freedom was so carefully-protected by constitutional framers at a time when even Jefferson expressed fear of legislative excess. For the loyalist executive and judiciary had been deposed, and the legislature was supreme in most States during and after the Revolution. “The legislative department is every where extending the sphere of its activity, and drawing all power into its impetuous vortex.” Madison, The Federalist, No. XLVIII.
  As other States joined the Union or revised their Constitutions, they took great care to preserve the principle that the legislature must be free to speak and act without fear of criminal and civil liability. Forty-one of the forty-eight States now have specific provisions in their Constitutions protecting the privilege.
  “If two or more persons in any State or Territory conspire, or go in disguise on the highway or on the premises of another, for the purpose of depriving, either directly or indirectly, any person or class of persons of the equal protection of the laws, or of equal privileges and immunities under the laws; or for the purpose of preventing or hindering the constituted authorities of any State or Territory from giving or securing to all persons within such State or Territory the equal protection of the laws; or if two or more persons conspire to prevent by force, intimidation, or threat, any citizen who is lawfully entitled to vote, from giving his support or advocacy in a legal manner, toward or in favor of the election of any lawfully qualified person as an elector for President or Vice-President, or as a member of Congress of the United States; or to injure any citizen in person or property on account of such support or advocacy; in any case of conspiracy set forth in this section, if one or more persons engaged therein do, or cause to be done, any act in furtherance of the object of such conspiracy, whereby another is injured in his person or property, or deprived of having and exercising any right or privilege of a citizen of the United States, the party so injured or deprived may have an action for the recovery of damages, occasioned by such injury or deprivation, against any one or more of the conspirators.”
  Did Congress by the general language of its 1871 statute mean to overturn the tradition of legislative freedom achieved in England by Civil War and carefully preserved in the formation of State and National Governments here? Did it mean to subject legislators to civil liability for acts done within the sphere of legislative activity? Let us assume, merely for the moment, that Congress has constitutional power to limit the freedom of State legislators acting within their traditional sphere. That would be a big assumption. But we would have to make an even rasher assumption to find that Congress thought it had exercised the power. These are difficulties we cannot hurdle. The limits of §§ 1 and 2 of the 1871 statute — now § § 43 and 47 (3) of Title 8 — were not spelled out in debate. We cannot believe that Congress — itself a staunch advocate of legislative freedom — would impinge on a tradition so well grounded in history and reason by covert inclusion in the general language before us.
  We come then to the question whether from the pleadings it appears that the defendants were acting in the sphere of legitimate legislative activity. Legislatures may not of course acquire power by an unwarranted extension of privilege. The House of Commons’ claim of power to establish the limits of its privilege has been little more than a pretense since Ashby v. White, 2 Ld. Raym. 938, 3 id. 320. This Court has not hesitated to sustain the rights of private individuals when it found Congress was acting outside its legislative role. Kilbourn v. Thompson, 103 U. S. 168; Marshall v. Gordon, 243 U. S. 521; compare McGrain v. Daugherty, 273 U. S. 135, 176.
  The claim of an unworthy purpose does not destroy the privilege. Legislators are immune from deterrents to the uninhibited discharge of their legislative duty, not for their private indulgence but for the public good. One must not expect uncommon courage even in legislators. The privilege would be of little value if they could be subjected to the cost and inconvenience and distractions of a trial upon a conclusion of the pleader, or to the hazard of a judgment against them based upon a jury’s speculation as to motives. The holding of this Court in Fletcher v. Peck, 6 Cranch 87, 130, that it was not consonant with our scheme of government for a court to inquire into the motives of legislators, has remained unquestioned. See cases cited in Arizona v. California, 283 U. S. 423, 455.
  Investigations, whether by standing or special committees, are an established part of representative government. Legislative committees have been charged with losing sight of their duty of disinterestedness. In times of political passion, dishonest or vindictive motives are readily attributed to legislative conduct and as readily believed. Courts are not the place for such controversies. Self-discipline and the voters must be the ultimate reliance for discouraging or correcting such abuses. The courts should not go beyond the narrow confines of determining that a committee’s inquiry may fairly be deemed within its province. To find that a committee’s investigation has exceeded the bounds of legislative power it must be obvious that there was a usurpation of functions exclusively vested in the Judiciary or the Executive. The present case does not present such a situation. Brand-hove indicated that evidence previously given by him to the committee was false, and he raised serious charges concerning the work of a committee investigating a problem within legislative concern. The Committee was entitled to assert a right to call the plaintiff before it and examine him.
  It should be noted that this is a case in which the defendants are members of a legislature. Legislative privilege in such a case deserves greater respect than where an official acting on behalf of the legislature is sued or the legislature seeks the affirmative aid of the courts to assert a privilege. In Kilbourn v. Thompson, supra, this Court allowed a judgment against the Sergeant-at-Arms, but found that one could not be entered against the defendant members of the House.
  We have only considered the scope of the privilege as applied to the facts of the present case. As Mr. Justice Miller said in the Kilbourn case: “It is not necessary to decide here that there may not be things done, in the one House or the other, of an extraordinary character, for which the members who take part in the act may be held legally responsible.” 103 U. S. at 204. We conclude only that here the individual defendants and the legislative committee were acting in a field where legislators traditionally have power to act, and that the statute of 1871 does not create civil liability for such conduct.
  The judgment of the Court of Appeals is reversed and that of the District Court affirmed.
  Reversed.
  R. S. § 1980 (par. Third), 8 U. S. C. § 47 (3):
  The Court of Appeals affirmed the dismissal as to Robinson on the ground that he was not acting under color of law and that the complaint did not show him to be a member of a conspiracy. We have denied a petition to review this decision. 341 U. S. 936.
  In two State Constitutions of 1776, the privilege was protected by general provisions preserving English law. See S. C. Const., 1776, Art. VII; N. J. Const., 1776, Art. XXII. Compare N. C. Const., 1776, § XLV.
  Three other of the original States made specific provision to protect legislative freedom immediately after the Federal Constitution was adopted. See Pa. Const., 1790, Ar.t. I, § 17; Ga. Const., 1789, Art. I, § 14; Del. Const., 1792, Art. II, § 11. Connecticut and Rhode Island so provided in the first constitutions enacted to replace their uncodi-fied organic law. Conn. Const., 1818, Art. Third, § 10; R. I. Const., 1842, Art. IV, § 5.
  In New York, the Bill of Rights passed by the legislature on January 26, 1787, provided: “That the freedom of speech and debates, and proceedings in the senate and assembly, shall not be impeached or questioned in any court or place out of the senate or assembly.” In Virginia, as well as in the other colonies, the assemblies had built up a strong tradition of legislative privilege long before the Revolution. See Clarke, Parliamentary Privilege in the American Colonies (1943), passim, especially 70 and 93 et seq.
  See Jefferson, Notes on the State of Virginia (3d Am. ed. 1801), 174^175. The Notes were written in 1781. See also, a letter from Jefferson to Madison, March 15,1789, to be published in a forthcoming volume of The Papers of Thomas Jefferson (Boyd ed.): “The tyranny of the legislatures is the most formidable dread at present, and will be for long years.” As to the political currents at the time the United States Constitution and the State Constitutions were formulated, see Corwin, The Progress of Constitutional Theory between the Declaration of Independence and the Meeting of the Philadelphia Convention, 30 Am. Hist. Rev. 511 (1925).
  Ala. Const., Art. IV, § 56; Ariz. Const., Art. IV, 2, § 7; Ark. Const., Art. V, § 15; Colo. Const., Art. V, § 16; Conn. Const., Art. Third, § 10; Del. Const., Art. II, § 13; Ga. Const., Art. Ill, § VII, par. Ill; Idaho Const., Art. Ill, § 7; Ill. Const., Art. IV, § 14; Ind. Const., Art. 4, §8; Kan. Const., Art. 2, §22; Ky. Const., §43; La. Const., Art. Ill, § 13; Me. Const., Art. IV, Pt. Third, §8; Md. D. R. 10, Const., Art. Ill, § 18; Mass. Const., Pt. First, Art. 21; Mich. Const., Art. V, §8; Minn. Const., Art. IV, §8; Mo. Const., Art. Ill, § 19; Mont. Const., Art. V, § 15; Neb. Const., Art. Ill, § 26; N. H. Const., Pt. First, Art. 30th; N. J. Const., Art. IV, § IV, par. 8; N. M. Const., Art. IV, § 13; N. Y. Const., Art. Ill, § 11; N. D. Const., Art. II, § 42; Ohio Const., Art. II, § 12; Okla. Const., Art. V, § 22; Ore. Const., Art. IV, § 9; Pa. Const., Art. II, § 15; R. I. Const., Art. IV, § 5; S. D. Const., Art. Ill, §11; Tenn. Const., Art. II, §13; Tex. Const., Art. Ill, §21; Utah Const., Art. VI, §8; Vt. Const., c. I, Art. 14th; Va. Const., Art. IV, §48; Wash. Const., Art. II, § 17; W. Va. Const., Art. VI, §17; Wis. Const., Art. IV, §16; Wyo. Const., Art. 3, § 16.
  Compare Iowa Const., Art. Ill, § 10; N. C. Const., Art. II, § 17 (right of legislator to protest action of legislature). See also, Cal. Const., Art. IV, §11; Iowa Const., Art. Ill, §11; Miss. Const., Art. 4, §48; Nev. Const., Art. IV, §11; S. C. Const., Art. Ill, § 14 (freedom from arrest). Only the Florida Constitution has no provision concerning legislative privilege.
  See Wilson, Congressional Government (1885), 303: “It is the proper duty of a representative body to look diligently into every affair of government and to talk much about what it sees. It is meant to be the eyes and the voice, and to embody the wisdom and will of its constituents. Unless Congress have and use every means of acquainting itself with the acts and the disposition of the administrative agents of the government, the country must be helpless to learn how it is being served; and unless Congress both scrutinize these things and sift them by every form of discussion, the country must remain in embarrassing, crippling ignorance of the very affairs which it is most important that it should understand and direct. The informing function of Congress should be preferred even to its legislative function.”
  See Dilliard, Congressional Investigations: The Role of the Press, 18 U. of Chi. L. Rev. 585.
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