MR. CHIEF JUSTICE WARREN delivered the opinion of the Court.

On the morning of March 31, 1966, David Paul O’Brien and three companions burned their Selective Service registration certificates on the steps of the South Boston Courthouse. A sizable crowd, including several agents of the Federal Bureau of Investigation, witnessed the event. Immediately after the burning, members of the crowd began attacking O’Brien and his companions. An FBI agent ushered O’Brien to safety inside the courthouse. After he was advised of his right to counsel and to silence, O’Brien stated to FBI agents that he had burned his registration certificate because of his beliefs, knowing that he was violating federal law. He produced the charred remains of the certificate, which, with his consent, were photographed.

For this act, O’Brien was indicted, tried, convicted, and sentenced in the United States District Court for the District of Massachusetts.  He did not contest the fact that he had burned the certificate. He stated in argument to the jury that he burned the certificate publicly to influence others to adopt his antiwar beliefs, as he put it, “so that other people would reevaluate their positions with Selective Service, with the armed forces, and reevaluate their place in the culture of today, to hopefully consider my position.”

The indictment upon which he was tried charged that he “willfully and knowingly did mutilate, destroy, and change by burning . . . [his] Registration Certificate in violation of Title 50, App., United States Code, Section 462 (b).” Section 462 (b) is part of the Universal Military Training and Service Act of 1948. Section 462 (b)(3), one of six numbered subdivisions of § 462 (b), was amended by Congress in 1965, 79 Stat. 586 (adding the words italicized below), so that at the time O’Brien burned his certificate an offense was committed by any person, “who forges, alters, knowingly destroys, knowingly mutilates, or in any manner changes any such certificate . . . .”

In the District Court, O’Brien argued that the 1965 Amendment prohibiting the knowing destruction or mutilation of certificates was unconstitutional because it was enacted to abridge free speech, and because it served no legitimate legislative purpose. The District Court rejected these arguments, holding that the statute on its face did not abridge First Amendment rights, that the court was not competent to inquire into the motives of Congress in enacting the 1965 Amendment, and that the Amendment was a reasonable exercise of the power of Congress to raise armies. On appeal, the Court of Appeals for the First Circuit held the 1965 Amendment unconstitutional as a law abridging freedom of speech…. The Government petitioned for certiorari in No. 232, arguing that the Court of Appeals erred in holding the statute unconstitutional, and that its decision conflicted with decisions by the Courts of Appeals for the Second and Eighth Circuits upholding the 1965 Amendment against identical constitutional challenges.  We granted the Government’s petition to resolve the conflict in the circuits.

I.

When a male reaches the age of 18, he is required by the Universal Military Training and Service Act to register with a local draft board. He is assigned a Selective Service number, and within five days he is issued a registration certificate (SSS Form No. 2).  Subsequently, and based on a questionnaire completed by the registrant, he is assigned a classification denoting his eligibility for induction, and “as soon as practicable” thereafter he is issued a Notice of Classification)….

Both the registration and classification certificates are small white cards, approximately 2 by 3 inches. The registration certificate specifies the name of the registrant, the date of registration, and the number and address of the local board with which he is registered. Also inscribed upon it are the date and place of the registrant’s birth, his residence at registration, his physical description, his signature, and his Selective Service number. The Selective Service number itself indicates his State of registration, his local board, his year of birth, and his chronological position in the local board’s classification record.

The classification certificate shows the registrant’s name, Selective Service number, signature, and eligibility classification. It specifies whether he was so classified by his local board, an appeal board, or the President. It contains the address of his local board and the date the certificate was mailed.

Both the registration and classification certificates bear notices that the registrant must notify his local board in writing of every change in address, physical condition, and occupational, marital, family, dependency, and military status, and of any other fact which might change his classification. Both also contain a notice that the registrant’s Selective Service number should appear on all communications to his local board.

Congress demonstrated its concern that certificates issued by the Selective Service System might be abused well before the 1965 Amendment here challenged.  In addition, as previously mentioned, regulations of the Selective Service System required registrants to keep both their registration and classification certificates in their personal possession at all times.

By the 1965 Amendment, Congress added to § 12 (b)(3) of the 1948 Act the provision here at issue, subjecting to criminal liability not only one who “forges, alters, or in any manner changes” but also one who “knowingly destroys, [or] knowingly mutilates” a certificate. We note at the outset that the 1965 Amendment plainly does not abridge free speech on its face, and we do not understand O’Brien to argue otherwise. Amended § 12 (b)(3) on its face deals with conduct having no connection with speech. It prohibits the knowing destruction of certificates issued by the Selective Service System, and there is nothing necessarily expressive about such conduct. The Amendment does not distinguish between public and private destruction, and it does not punish only destruction engaged in for the purpose of expressing views. A law prohibiting destruction of Selective Service certificates no more abridges free speech on its face than a motor vehicle law prohibiting the destruction of drivers’ licenses, or a tax law prohibiting the destruction of books and records.

O’Brien nonetheless argues that the 1965 Amendment is unconstitutional in its application to him, and is unconstitutional as enacted because what he calls the “purpose” of Congress was “to suppress freedom of speech.” We consider these arguments separately.

II.

O’Brien first argues that the 1965 Amendment is unconstitutional as applied to him because his act of burning his registration certificate was protected “symbolic speech” within the First Amendment. His argument is that the freedom of expression which the First Amendment guarantees includes all modes of “communication of ideas by conduct,” and that his conduct is within this definition because he did it in “demonstration against the war and against the draft.”

We cannot accept the view that an apparently limitless variety of conduct can be labeled “speech” whenever the person engaging in the conduct intends thereby to express an idea. However, even on the assumption that the alleged communicative element in O’Brien’s conduct is sufficient to bring into play the First Amendment, it does not necessarily follow that the destruction of a registration certificate is constitutionally protected activity. This Court has held that when “speech” and “nonspeech” elements are combined in the same course of conduct, a sufficiently important governmental interest in regulating the nonspeech element can justify incidental limitations on First Amendment freedoms. To characterize the quality of the governmental interest which must appear, the Court has employed a variety of descriptive terms: compelling; substantial; subordinating; paramount; cogent; strong. Whatever imprecision inheres in these terms, we think it clear that a government regulation is sufficiently justified if it is within the constitutional power of the Government; if it furthers an important or substantial governmental interest; if the governmental interest is unrelated to the suppression of free expression; and if the incidental restriction on alleged First Amendment freedoms is no greater than is essential to the furtherance of that interest. We find that the 1965 Amendment to § 12 (b)(3) of the Universal Military Training and Service Act meets all of these requirements, and consequently that O’Brien can be constitutionally convicted for violating it.

The constitutional power of Congress to raise and support armies and to make all laws necessary and proper to that end is broad and sweeping.  The power of Congress to classify and conscript manpower for military service is “beyond question.”  Pursuant to this power, Congress may establish a system of registration for individuals liable for training and service, and may require such individuals within reason to cooperate in the registration system. The issuance of certificates indicating the registration and eligibility classification of individuals is a legitimate and substantial administrative aid in the functioning of this system. And legislation to insure the continuing availability of issued certificates serves a legitimate and substantial purpose in the system’s administration.

O’Brien’s argument to the contrary is necessarily premised upon his unrealistic characterization of Selective Service certificates. He essentially adopts the position that such certificates are so many pieces of paper designed to notify registrants of their registration or classification, to be retained or tossed in the wastebasket according to the convenience or taste of the registrant. Once the registrant has received notification, according to this view, there is no reason for him to retain the certificates. O’Brien notes that most of the information on a registration certificate serves no notification purpose at all; the registrant hardly needs to be told his address and physical characteristics. We agree that the registration certificate contains much information of which the registrant needs no notification. This circumstance, however, does not lead to the conclusion that the certificate serves no purpose, but that, like the classification certificate, it serves purposes in addition to initial notification. Many of these purposes would be defeated by the certificates’ destruction or mutilation. Among these are:

1. The registration certificate serves as proof that the individual described thereon has registered for the draft….  Additionally, in a time of national crisis, reasonable availability to each registrant of the two small cards assures a rapid and uncomplicated means for determining his fitness for immediate induction, no matter how distant in our mobile society he may be from his local board.

2. The information supplied on the certificates facilitates communication between registrants and local boards, simplifying the system and benefiting all concerned….

3. Both certificates carry continual reminders that the registrant must notify his local board of any change of address, and other specified changes in his status.

4. The regulatory scheme involving Selective Service certificates includes clearly valid prohibitions against the alteration, forgery, or similar deceptive misuse of certificates. The destruction or mutilation of certificates obviously increases the difficulty of detecting and tracing abuses such as these. Further, a mutilated certificate might itself be used for deceptive purposes.

The many functions performed by Selective Service certificates establish beyond doubt that Congress has a legitimate and substantial interest in preventing their wanton and unrestrained destruction and assuring their continuing availability by punishing people who knowingly and wilfully destroy or mutilate them. And we are unpersuaded that the pre-existence of the nonpossession regulations in any way negates this interest.

We think it apparent that the continuing availability to each registrant of his Selective Service certificates substantially furthers the smooth and proper functioning of the system that Congress has established to raise armies. We think it also apparent that the Nation has a vital interest in having a system for raising armies that functions with maximum efficiency and is capable of easily and quickly responding to continually changing circumstances. For these reasons, the Government has a substantial interest in assuring the continuing availability of issued Selective Service certificates.

It is equally clear that the 1965 Amendment specifically protects this substantial governmental interest. We perceive no alternative means that would more precisely and narrowly assure the continuing availability of issued Selective Service certificates than a law which prohibits their wilful mutilation or destruction. The 1965 Amendment prohibits such conduct and does nothing more. In other words, both the governmental interest and the operation of the 1965 Amendment are limited to the noncommunicative  aspect of O’Brien’s conduct. The governmental interest and the scope of the 1965 Amendment are limited to preventing harm to the smooth and efficient functioning of the Selective Service System. When O’Brien deliberately rendered unavailable his registration certificate, he wilfully frustrated this governmental interest. For this noncommunicative impact of his conduct, and for nothing else, he was convicted.

III.

O’Brien finally argues that the 1965 Amendment is unconstitutional as enacted because what he calls the “purpose” of Congress was “to suppress freedom of speech.” We reject this argument because under settled principles the purpose of Congress, as O’Brien uses that term, is not a basis for declaring this legislation unconstitutional.

It is a familiar principle of constitutional law that this Court will not strike down an otherwise constitutional statute on the basis of an alleged illicit legislative motive. Inquiries into congressional motives or purposes are a hazardous matter. When the issue is simply the interpretation of legislation, the Court will look to statements by legislators for guidance as to the purpose of the legislature, because the benefit to sound decision-making in this circumstance is thought sufficient to risk the possibility of misreading Congress’ purpose. It is entirely a different matter when we are asked to void a statute that is, under well-settled criteria, constitutional on its face, on the basis of what fewer than a handful of Congressmen said about it. What motivates one legislator to make a speech about a statute is not necessarily what motivates scores of others to enact it, and the stakes are sufficiently high for us to eschew guesswork. We decline to void essentially on the ground that it is unwise legislation which Congress had the undoubted power to enact and which could be reenacted in its exact form if the same or another legislator made a “wiser” speech about it.

We think it not amiss, in passing, to comment upon O’Brien’s legislative-purpose argument. There was little floor debate on this legislation in either House. Only Senator Thurmond commented on its substantive features in the Senate. After his brief statement, and without any additional substantive comments, the bill, passed the Senate. In the House debate only two Congressmen addressed themselves to the Amendment — Congressmen Rivers and Bray. The bill was passed after their statements without any further debate by a vote of 393 to 1. It is principally on the basis of the statements by these three Congressmen that O’Brien makes his congressional-“purpose” argument. We note that if we were to examine legislative purpose in the instant case, we would be obliged to consider not only these statements but also the more authoritative reports of the Senate and House Armed Services Committees. The portions of those reports explaining the purpose of the Amendment are reproduced in the Appendix in their entirety. While both reports make clear a concern with the “defiant” destruction of so-called “draft cards” and with “open” encouragement to others to destroy their cards, both reports also indicate that this concern stemmed from an apprehension that unrestrained destruction of cards would disrupt the smooth functioning of the Selective Service System.

IV.

Since the 1965 Amendment to § 12 (b)(3) of the Universal Military Training and Service Act is constitutional as enacted and as applied, the Court of Appeals should have affirmed the judgment of conviction entered by the District Court. Accordingly, we vacate the judgment of the Court of Appeals, and reinstate the judgment and sentence of the District Court.