Mr. Chief Justice Warren
delivered the opinion of the Court.
Petitioner was convicted of contempt of Congress under 2 U. S. C. § 192 in the District Court for the District of Columbia. Section 192 provides for the punishment of any witness before a congressional committee “who . . . refuses to answer any question pertinent to the question under inquiry . ...” On appeal, the Court of Appeals for the District of Columbia Circuit reversed the conviction and remanded the case for a new trial. Claiming that the Court of Appeals should have directed an acquittal, petitioner applied to this Court for certiorari. We granted the writ because of the fundamental and recurrent character of the questions presented.
Pursuant to subpoena, petitioner appeared on August 10, 1949, before a subcommittee of the Committee on Un-American Activities of the House of Representatives. Petitioner was then a member and field representative of the United Electrical, Radio and Machine Workers of America. Also subpoenaed to appear on that day were Thomas J. Fitzpatrick and Frank Panzino, two officers of the same union. At the outset of the hearings, counsel for the committee announced that the purpose of the investigation was to inquire into “the question of Communist affiliation or association of certain members” of the union and “the advisability of tightening present security requirements in industrial plants working on certain Government contracts.” All three witnesses were asked questions concerning alleged membership in the Communist Party. All three declined to answer.
Fitzpatrick was the first to be called to testify. He based his refusal to answer on “the first and fifth amendments” as well as “the first amendment to the
Constitution, supplemented by the fifth amendment.” Immediately following Fitzpatrick’s testimony, Panzino was called to the stand. In response to the identical questions put to Fitzpatrick, Panzino specifically adopted as his own the grounds relied upon by Fitzpatrick. In addition, at one point in his testimony, Panzino stated that “I think again, Mr. Chairman, under the fifth amendment, that is my own personal belief.” On the following day, petitioner, unaccompanied by counsel, was called to the stand and was also asked whether he had ever been a member of the Communist Party. Like Panzino before him, he declined to answer, specifically adopting as his own the grounds relied upon by Fitzpatrick.
On November 20, 1950, all three witnesses were indicted under § 192 for their refusals to answer. The three cases were tried before different judges, each sitting without a jury. Fitzpatrick and Panzino were acquitted. In Fitzpatrick’s case, it was held that his references to “the first and fifth amendments” and “the first amendment to the Constitution, supplemented by the fifth amendment” constituted an adequate means of invoking the Self-Incrimination Clause of the Fifth Amendment. Similarly, in Panzino’s case, it was held that his reference to “the fifth amendment” was sufficient to plead the privilege. In petitioner’s case, however, the District Court held that a witness may not incorporate the position of another witness and rejected petitioner’s defense based on the Self-Incrimination Clause. Petitioner was accordingly convicted and sentenced to a term of six months in jail and a fine of $500.
In reversing this conviction, the Court of Appeals, sitting en banc, held that “No formula or specific term or expression is required” in order to plead the privilege and that a witness may adopt as his own a plea made by a previous witness. Thus the Court of Appeals viewed the principal issue in the case as “whether Fitzpatrick did or did not claim the privilege.” On this issue, a majority of the Court of Appeals expressed no view. They agreed that a reversal without more would be in order if they “were of clear opinion that Fitzpatrick, and therefore Quinn, did claim the privilege.” But they were “not of that clear opinion.” The Court of Appeals therefore ordered a new trial for determination of the issue by the District Court. The Court of Appeals also directed the District Court on retrial to determine whether petitioner “was aware of the intention of his inquirer that answers were required despite his objections.” In that regard, however, it rejected petitioner’s contention that a witness cannot be convicted under § 192 for a refusal to answer unless the committee overruled his objections and specifically directed him to answer.
It is from that decision that this Court granted certiorari.
I.
There can be no doubt as to the power of Congress, by itself or through its committees, to investigate matters and conditions relating to contemplated legislation. This power, deeply rooted in American and English institutions, is indeed co-extensive with the power to legislate. Without the power to investigate — including of course the authority to compel testimony, either through its own processes or through judicial trial — Congress could be seriously handicapped in its efforts to exercise its constitutional function wisely and effectively.
But the power to investigate, broad as it may be, is J also subject to recognized limitations. It cannot be used to inquire into private affairs unrelated to a valid legislative purpose. Nor does it extend to an area in which Congress is forbidden to legislate. Similarly, the power to investigate must not be confused with any of the powers of law enforcement; those powers are assigned under our Constitution to the Executive and the Judiciary. Still further limitations on the power to investigate are found in the specific individual guarantees of the Bill of Rights, such as the Fifth Amendment’s privilege against self-incrimination which is in issue here.
The privilege against self-incrimination is a right that was hard-earned by our forefathers. The reasons for its inclusion in the Constitution — and the necessities for its preservation — are to be found in the lessons of history. As early as 1650, remembrance of the horror of Star Chamber proceedings a decade before had firmly established the privilege in the common law of England. Transplanted to this country as part of our legal heritage, it soon made its way into various state constitutions and ultimately in 1791 into the federal Bill of Rights. The privilege, this Court has stated, “was generally regarded then, as now, as a privilege of great value, a protection to the innocent though a shelter to the guilty, and a safeguard against heedless, unfounded or tyrannical prosecutions.” Coequally with our other constitutional guarantees, the Self-Incrimination Clause “must be accorded liberal construction in favor of the right it was intended to secure.” Such liberal construction is particularly warranted in a prosecution of a witness for a refusal to answer, since the respect normally accorded the privilege is then buttressed by the presumption of innocence accorded a defendant in a criminal trial. To apply the privilege narrowly or begrudgingly — to treat it as an historical relic, at most merely to be tolerated — is to ignore its development and purpose.
In the instant case petitioner was convicted for refusing to answer the committee’s question as to his alleged membership in the Communist Party. Clearly an answer to the question might have tended to incriminate him. As a consequence, petitioner was entitled to claim the privilege. The principal issue here is whether or not he did.
It is agreed by all that a claim of the privilege does not require any special combination of words. Plainly a witness need not have the skill of a lawyer to invoke the protection of the Self-Incrimination Clause. If an objection to a question is made in any language that a committee may reasonably be expected to understand as an attempt to invoke the privilege, it must be respected both by the committee and by a court in a prosecution under § 192.
Here petitioner, by adopting the grounds relied upon by Fitzpatrick, based his refusal to answer on “the first and fifth amendments” and “the first amendment to the Constitution, supplemented by the fifth amendment.” The Government concedes — as we think it must — that a witness may invoke the privilege by stating “I refuse to testify on the ground of the Fifth Amendment.” Surely, in popular parlance and even in legal literature, the term “Fifth Amendment” in the context of our time is commonly regarded as being synonymous with the privilege against self-incrimination. The Government argues, however, that the references to the Fifth Amendment in the instant case were inadequate to invoke the privilege because Fitzpatrick’s statements are more reasonably understood as invoking rights under the First Amendment. We find the Government’s argument untenable. The mere fact that Fitzpatrick and petitioner also relied on the First Amendment does not preclude their reliance on the Fifth Amendment as well. If a witness urges two constitutional objections to a committee’s line of questioning, he is not bound at his peril to choose between them. By pressing both objections, he does not lose a privilege which would have been valid if he had only relied on one.
The Government, moreover, apparently concedes that petitioner intended to invoke the privilege. In its brief the Government points out “the probability that petitioner’s ambiguous references to the Fifth Amendment . . . were phrased deliberately in such vague terms so as to enable petitioner ... to obtain the benefit of the privilege without incurring the popular opprobrium which often attaches to its exercise.” But the fact that a witness expresses his intention in vague terms is immaterial so long as the claim is sufficiently definite to apprise the committee of his intention. As everyone agrees, no ritualistic formula is necessary in order to invoke the privilege. In the instant case, Quinn’s references to the Fifth Amendment were clearly sufficient to put the committee on notice of an apparent claim of the privilege. It then became incumbent on the committee either to accept the claim or to ask petitioner whether he was in fact invoking the privilege. Particularly is this so if it is true, as the Government contends, that petitioner feared the stigma that might result from a forthright claim of his constitutional right to refuse to testify. It is precisely at such times — when the privilege is under attack by those who wrongly conceive of it as merely a shield for the guilty — that governmental bodies must be most scrupulous in protecting its exercise.
This ruling by no means leaves a congressional committee defenseless at the hands of a scheming witness intent on deception. When a witness declines to answer a question because of constitutional objections and the language used is not free from doubt, the way is always open for the committee to inquire into the nature of the claim before making a ruling. If the witness unequivocally and intelligently waives any objection based on the Self-Incrimination Clause, or if the witness refuses a committee request to state whether he relies on the Self-Incrimination Clause, he cannot later invoke its protection in a prosecution for contempt for refusing to answer that question. Here the committee made no attempt to have petitioner particularize his objection. Under these circumstances, we must hold that petitioner’s references to the Fifth Amendment were sufficient to invoke the privilege and that the court below erred in failing to direct a judgment of acquittal.
II.
There is yet a second ground for our decision.
Section 192, like the ordinary federal criminal statute, requires a criminal intent — in this instance, a deliberate, intentional refusal to answer. This element of the offense, like any other, must be proved beyond a reasonable doubt. Petitioner contends that such proof was not, and cannot be, made in this case.
Clearly not every refusal to answer a question propounded by a congressional committee subjects a witness to prosecution under § 192. Thus if he raises an objection to a certain question — for example, lack of perti-nency or the privilege against self-incrimination — the committee may sustain the objection and abandon the question, even though the objection might actually be without merit. In such an instance, the witness’ refusal to answer is not contumacious, for there is lacking the requisite criminal intent. Or the committee may disallow the objection and thus give the witness the choice of answering or not. Given such a choice, the witness may recede from his position and answer the question. And if he does not then answer, it may fairly be said that the foundation has been laid for a finding of criminal intent to violate § 192. In short, unless the witness is clearly apprised that the committee demands his answer notwithstanding his objections, there can be no conviction under § 192 for refusal to answer that question.
Was petitioner so apprised here? At no time did the committee specifically overrule his objection based on the Fifth Amendment; nor did the committee indicate its overruling of the objection by specifically directing petitioner to answer. In the absence of such committee action, petitioner was never confronted with a clear-cut choice between compliance and noncompliance, between answering the question and risking prosecution for contempt. At best he was left to guess whether or not the committee had accepted his objection.
This ambiguity in the committee’s position is apparent from the transcript of the hearing. Immediately after petitioner stated that he was adopting Fitzpatrick’s objection, the committee chairman asked petitioner: “. . . will you now answer the question whether you are now or ever have been a member of the Communist Party, or do you decline to answer?” In response to this, petitioner stated for the first time that he would not answer. He said: “I decline to discuss with the committee questions of that nature.” Committee counsel thereupon stated that further questioning “relating to those matters” was “not necessary” and proceeded upon a new line of inquiry. There is nothing in this colloquy from which petitioner could have determined with a reasonable degree of certainty that the committee demanded his answer despite his objection. Rather, the colloquy is wholly consistent with the hypothesis that the committee had in fact acquiesced in his objection.
Our view that a clear disposition of the witness’ objection is a prerequisite to prosecution for contempt is supported by long-standing tradition here and in other English-speaking nations. In this country the tradition has been uniformly recognized in the procedure of both state and federal courts. It is further reflected in the practice of congressional committees prior to the enactment of § 192 in 1857; a specific direction to answer was the means then used to apprise a witness of the overruling of his objection. Against this background § 192 became law. No relaxation of the safeguards afforded a witness was contemplated by its sponsors. In explaining the bill in the House, Congressman Davis expressly stated that committee powers were not increased, that no added burden was placed upon the witness, and that a “mere substitution” of a judicial proceeding for punishment at the bar of Congress was intended. The reason for enacting § 192 went to the punishment and not the offense. It was recognized that the power of Congress to-deal with a contemnor by its own processes did not extend beyond the life of any session. By making contempt of Congress a crime, a fixed term of imprisonment was substituted for variable periods of congressional custody dependent upon the fortuity of whether the contemnor had been called to testify near the beginning or the end of a session. But there is nothing to indicate that this change in the mode of punishment affected in any way the well-established elements of contempt of Congress. Since the enactment of § 192, the practice of specifically directing a recalcitrant witness to answer has continued to prevail. In fact, the very committee involved here, the House Un-American Activities Committee, originally followed this practice and recently resumed it.
Giving a witness a fair apprisal of the committee’s ruling on an objection recognizes the legitimate interests of both the witness and the committee. Just as the witness need not use any particular form of words to present his objection, so also the committee is not required to resort to any fixed verbal formula to indicate its disposition of the objection. So long as the witness is not forced to guess the committee’s ruling, he has no cause to complain. And adherence to this traditional practice can neither inflict hardship upon the committee nor abridge the proper scope of legislative investigation.
III
Petitioner also attacks his conviction on grounds involving novel constitutional issues. He contends that the House Resolution authorizing the committee’s operations is invalid under the First Amendment. In addition, petitioner contends that the trial court erred in denying a hearing on the alleged bias of the indicting grand jury. Our disposition of the case makes it unnecessary to pass on these issues.
The judgment below is reversed and the case remanded to the District Court with directions to enter a judgment of acquittal.
Reversed.
The section provides in full:
“Every person who having been summoned as a witness by the authority of either House of Congress to give testimony or to produce papers upon any matter under inquiry before either House, or any joint committee established by a joint or concurrent resolution of the two Houses of Congress, or any committee of either House of Congress, willfully makes default, or who, having appeared, refuses to answer any question pertinent to the question under inquiry, shall be deemed guilty of a misdemeanor, punishable by a fine of not more than $1,000 nor less than $100 and imprisonment in a common jail for not less than one month nor more than twelve months.”
91 U. S. App. D. C. 344, 203 F. 2d 20.
347 U. S. 1008.
Hearings before House Committee on Un-American Activities Regarding Communist Infiltration of Labor Unions, 81st Cong., 1st Sess., Part I, 541-542.
Id., at 602, 604.
Id., at 608.
Id., at 609.
Id., at 634-635:
“Mr. Quinn. I would like to make a statement along the lines that Mr. Fitzpatrick made yesterday in regard to a question of that nature. I feel that the political beliefs, opinions, and associations of the American people can be held secret if they so desire.
“Mr. Wood. And for those reasons do you decline to answer that question ?
“Mr. Quinn. I didn’t say I was declining to answer the question. Before I do answer the question I should like to say that I support the position taken by Brother Fitzpatrick yesterday.
“Mr. Wood. Did you hear his statement yesterday?
“Mr. Quinn. Yes; I did.
“Mr. Wood. Do you support it in'its entirety?
“Mr. Quinn. In its entirety.
“Mr. Wood. Is there anything else you want to add to it?
“Mr. Quinn. No; I don’t.
“Mr. Wood. Will you accept it as the expression of your views, then?
“Mr. Quinn. You may. I may add I feel I have no other choice in this matter, because the defense of the Constitution, I hold sacred. I don't feel I am hiding behind the Constitution, but in this case I am’ standing before it, defending it, as small as I am.
“Mr. Wood. Having made that statement and subscribed to the sentiments expressed by the witness yesterday to whom you referred, will you now answer the question whether you are now or have ever been a member of the Communist Party?
“Mr. QuiNN. I hold that the Constitution holds sacred the rights of people-
“Mr. Wood. You have stated your position. Having enunciated your sentiments and your position, will you now answer the question whether you are now or ever have been a member of the Communist Party, or do you decline to answer?
“Mr. QuinN. I decline to discuss with the committee questions of that nature.
“Mr. Wood. Proceed, Mr. Tavenner.
“Mr. TavenNER. I believe in the light of that answer it is not necessary to ask you any further questions relating to those matters, so I will ask you this: Do you know Mr. James J. Matles?
“Mr. QuinN. Yes.”
Petitioner’s motions to dismiss the indictment were denied sub nom. United States v. Emspak, 95 F. Supp. 1010, 1012 (D. D. C.).
United States v. Fitzpatrick, 96 F. Supp. 491 (D. D. C.).
United States v. Panzino, unreported, Criminal No. 1747-50 (D.D.C.).
United States v. Quinn, unreported, Criminal No. 1744-50 (D. D. C.).
91 U. S. App. D. C. 344, 347, 203 F. 2d 20, 23.
Id., at 347, 203 F. 2d, at 23.
Id., at 348, 203 F. 2d, at 24.
Ibid.
Id., at 349, 203 F. 2d, at 25.
Ibid.
Cf. Anderson v. Dunn, 6 Wheat. 204.
In re Chapman, 166 U. S. 661.
See McGrain v. Daugherty, 273 U. S. 135, 175.
Id., at 173-174; Kilbourn v. Thompson, 103 U. S. 168, 190.
Compare United States v. Rumely, 345 U. S. 41, 46.
Kilbourn v. Thompson, 103 U. S. 168, 192-193.
The Amendment provides in pertinent part that “No person . . . shall be compelled in any criminal case to be a witness against himself . . . .”
See Griswold, The Fifth Amendment Today, 2-7.
Twining v. New Jersey, 211 U. S. 78, 91. See also Boyd v. United States, 116 U. S. 616, 631-632.
Hoffman v. United States, 341 U. S. 479, 486. Cf. Counselman v. Hitchcock, 142 U. S. 547, 562.
Blau v. United States, 340 U. S. 159, specifically holding that such a question is protected by the privilege; Brunner v. United States, 343 U. S. 918, reversing 190 F. 2d 167 (C. A. 9th Cir.). See also Hoffman v. United States, 341 U. S. 479.
Compare Smith v. United States, 337 U. S. 137, where the Court characterized a witness’ statement “I want to claim privilege as to anything that I say” (p. 142) as a “definite claim of general privilege against self-incrimination” (p. 151).
As to the close relationship between the First Amendment and the privilege against self-incrimination, see Griswold, supra, note 26, at 8-9.
Brief for United States, p. 33. The Government makes the same contention as to the petitioner in No. 9, Emspak v. United States, post, p. 190.
Sinclair v. United States, 279 U. S. 263, 299. See also In re Chapman, 166 U. S. 661, 672, in which the Court, while upholding-the constitutionality of the statute, recognized deliberateness as an element of the offense.
See United States v. Kamp, 102 F. Supp. 757, 759 (D. D. C.): “Committees of Congress must conduct examinations in such a manner that it is clear to the witness that the Committee recognizes him as being in default, and anything short of a clear cut default on the part of the witness will not sustain a conviction for contempt of Congress. The transcript of the defendant Kamp’s testimony fails to disclose such a clear cut default. The witness is not required to enter into a guessing game when called upon to appear before a committee. The burden is upon the presiding member to make clear the directions of the committee, to consider any reasonable explanations given by the witness, and then to rule on the witness’ response.” The defendant was accordingly acquitted.
On similar grounds, an acquittal was directed in United States v. Browder, unreported, Criminal No. 1784-50 (D. D. C.).
See note 8, supra.
While of course not binding on Congress or its committees, the practice in the States and other English-speaking jurisdictions is at least worthy of note.
For examples relating to recalcitrant witnesses before state legislative committees, see Ex parte McCarthy, 29 Cal. 395, 398; People v. Keeler, 99 N. Y. 463, 471, 2 N. E. 615, 617; Lowe v. Summers, 69 Mo. App. 637, 645.
Recalcitrant witnesses before investigating committees of the British House of Commons have traditionally been apprised of the disposition of their objections and given subsequent opportunity to respond before being subjected to the contempt power of the legislature. The practice has been as follows: The committee reports the failure to answer to the House. The witness is questioned about the cause of the refusal to answer before the Bar of the House. The House then votes on the validity of the objection. If the claim is rejected, the witness is specifically directed to answer. Only after a subsequent refusal is punishment imposed. See 88 Journals of the House of Commons 212, 218 (Case of Elizabeth Robinson before Select Committee on Liverpool Bribery, 1833); 90 Journals of the House of Commons 501, 504, and 29 Hans. Deb., 3d Ser., 1249, 1279-1288 (Case of William Prentice before Select Committee on Great Yar-mouth Bribery, 1835); 90 Journals of the House of Commons, 564, 571, 575 (Case of Lieutenant Colonel Fairman before Select Committee on the Orange Lodges, 1835); 152 Journals of the House of Commons 361, 365 (Case of John Kirkwood before Select Committee on Money Lending, 1897).
For Canadian practice, see the case of W. T. R. Preston before the Committee on Public Accounts, the Committee on Agriculture and Colonization, and the House of Commons. 41 Journals of the House of Commons, Canada, 298, 316, 323; 41 id., Appendix No. 2, 324-327; 41 id., Appendix No. 3, 250-251; 76 Debates, House of Commons, Canada, Session 1906, Vol. III, 4451-4535.
See Hoffman v. United States, 341 U. S. 479, 486: “It is for the court to say whether his silence is justified . . . and to require him to answer if ‘it clearly appears to the court that he is mistaken.’ ” See also Chief Justice Marshall in United States v. Burr, 25 Fed. Cas. 38, at 40, No. 14,692e: “When a question is propounded, it belongs to the court to consider and to decide whether any direct answer to it can implicate the witness.” The cases, both federal and state, are collected in Wigmore, Evidence, § 2271. See, e. g., Carlson v. United States, 209 F. 2d 209, 214 (C. A. 1st Cir.), and Gendron v. Burnham, 146 Me. 387, 405-406, 82 A. 2d 773, 784-785.
See, e. g., the resolution introduced by Congressman Orr proposing that one J. W. Simonton be haled before the bar of the House of Representatives for refusing to answer a question put to him by a duly-authorized committee of that body. Cong. Globe, 34th Cong., 3d Sess. 403-404 (1857). The resolution states in part:
“The committee were impressed with the materiality of the testimony withheld by the witness, as it embraced the letter and spirit of the inquiry directed by the House to be made, but were anxious to avoid any controversy with the witness. They consequently waived the interrogatory that day, to give the witness time for reflection on the consequences of his refusal, and to afford him an opportunity to look into the law and the practice of the House in such cases, notifying him that he would, on some subsequent day, be recalled. This was the 15th of January instant. On Tuesday, the 20th instant, the said J. W. Simonton was recalled, and the identical question first referred to was again propounded, after due notice to him that if he declined the committee would feel constrained to report his declination to the House, and ask that body to enforce all its powers in the premises to compel a full and complete response.” Id., at 403. See also id., 31st Cong., 1st Sess. 1716 (1850).
Act of Jan. 24, 1857, c. 19, § 1, 11 Stat. 155.
Cong. Globe, 34th Cong., 3d Sess. 427.
Anderson v. Dunn, 6 Wheat. 204, 230-231.
Cong. Globe, supra, note 40, at 405 et seq.
See, e. g., Cong. Globe, 40th Cong., 3d Sess. 771-772 (1869); id., 42d Cong., 3d Sess. 952 (1873); 4 Cong. Rec. 1705 et seq. (1876) (citation of Hallet Kilbourn, involved in Kilbourn v. Thompson, supra, note 22); 26 Cong. Rec. 6143 et seq. (1894) (citation of Elverton R. Chapman, involved in In re Chapman, supra, note 20); 65 Cong. Rec. 4785 et seq. (1924) (citation of Harry F. Sinclair, involved in Sinclair v. United States, supra, note 33); 69 Cong. Rec. 2439, 5286, 5353, 7239 (1928); 78 Cong. Rec. 1902, 1911-1914 (1934); 86 Cong. Rec. 3856 (1940); 90 Cong. Rec. 8163 (1944); 97 Cong. Rec. 499 et seq. (1951).
See, e. g., the contempt citation of George Powers at 86 Cong. Rec. 3856-3857. See also the citation of James H. Dolsen, id., at 3694-3695.
See contempt citation of Saul Grossman, 98 Cong. Rec. 8634-8637.