In addition to safeguarding the right of one individual to receive what another elects to communicate, the First Amendment serves an essential societal function. (20) Our system of self-government assumes the existence of an informed citizenry. (21) As Madison wrote:

"A popular Government, without popular information, or the means of acquiring it, is but a Prologue to a Farce or a Tragedy; or, perhaps both. Knowledge will forever govern ignorance: And a people who mean to be their own Governors, must arm themselves with the power which knowledge gives." 9 Writings of James Madison 103 (G. Hunt ed. 1910).

It is not sufficient, therefore, that the channels of communication be free of governmental restraints. Without some protection for the acquisition of information about the operation of public institutions such as prisons by the public at large, the process of self-governance contemplated by the Framers would be stripped of its substance. (22)

( Footnote 20 ) "What is at stake here is the societal function of the First Amendment in preserving free public discussion of governmental affairs. No aspect of that constitutional guarantee is more rightly treasured than its protection of the ability of our people through free and open debate to consider and resolve their own destiny. . . . It embodies our Nation's commitment to popular self-determination and our abiding faith that the surest course for developing sound national policy lies in a free exchange of views on public issues. And public debate must not only be unfettered; it must also be informed. For that reason this Court has repeatedly stated that First Amendment concerns encompass the receipt of information and ideas as well as the right of free expression." Saxbe v. Washington Post Co., 417 U.S. 843, 862 -863 (POWELL, J., dissenting).

( Footnote 21 ) See A. Meiklejohn, Free Speech and Its Relation to Self-Government 26 (1948):

"Just so far as . . . the citizens who are to decide an issue are denied acquaintance with information or opinion or doubt or disbelief or criticism which is relevant to that issue, just so far the result must be ill-considered, ill-balanced planning, for the general good. It is that mutilation of the thinking process of the community against which the First Amendment to the Constitution is directed."

( Footnote 22 ) Admittedly, the right to receive or acquire information is not specifically mentioned in the Constitution. But "the protection of the Bill of Rights goes beyond the specific guarantees to protect from . . . abridgement those equally fundamental personal rights necessary to make the express guarantees fully meaningful. . . . The dissemination of ideas can accomplish nothing if otherwise willing addressees are not free to receive and consider them. It would be a barren marketplace of ideas that had only sellers and no buyers." Lamont v. Postmaster General, 381 U.S., at 308 (BRENNAN, J., concurring). It would be an even more barren market-place that had willing buyers and sellers and no meaningful information to exchange.

(T)here are unquestionably occasions when governmental activity may properly be carried on in complete secrecy. For example, the public and the press are commonly excluded from "grand jury proceedings, our own conferences, (and) the meetings of other official bodies gathered in executive session . . . ." Branzburg v. Hayes, 408 U.S., at 684 ; Pell v. Procunier, 417 U.S., at 834 . (26) In addition, some functions of government - essential to the protection of the public and indeed our country's vital interests - necessarily require a large measure of secrecy, subject to appropriate legislative oversight. (27) In such situations the reasons for withholding information from the public are both apparent and legitimate.

In this case, however, &quot r)espondents do not assert a right to force disclosure of confidential information or to invade in any way the decisionmaking processes of governmental officials." (28) They simply seek an end to petitioner's policy of concealing prison conditions from the public. Those conditions are wholly without claim to confidentiality. While prison officials have an interest in the time and manner of public acquisition of information about the institutions they administer, there is no legitimate penological justification for concealing from citizens the conditions in which their fellow citizens are being confined. (29)

( Footnote 26 ) In the case of grand jury proceedings, for example, the secrecy rule has been justified on several grounds:

"`(1) To prevent the escape of those whose indictment may be contemplated; (2) to insure the utmost freedom to the grand jury in its deliberations, and to prevent persons subject to indictment or their friends from importuning the grand jurors; (3) to prevent subornation of perjury or tampering with the witnesses who may testify before grand jury and later appear at the trial of those indicted by it; (4) to encourage free and untrammeled disclosures by persons who have information with respect to the commission of crimes; (5) to protect innocent accused who is exonerated from disclosure of the fact that he has been under investigation, and from the expense of standing trial where there was no probability of guilt.'" United States v. Procter & Gamble Co., 356 U.S. 677, 681 -682, n. 6, quoting United States v. Rose, 215 F.2d 617, 628-629 (CA3 1959).

( Footnote 27 ) In United States v. Nixon, supra, we also recognized the valid need for protection of communications between high Government officials and those who advise and assist them in the performance of their manifold duties, explaining that "the importance of this confidentiality is too plain to require further discussion. Human experience teaches that those who expect public dissemination of their remarks may well temper candor with a concern for appearances and for their own interests to the detriment of the decisionmaking process." 418 U.S., at 705 .

( Footnote 28 ) Saxbe v. Washington Post Co., 417 U.S., at 861 (POWELL, J., dissenting).

( Footnote 29 ) The Court in Saxbe noted that "`prisons are institutions where public access is generally limited.'" Id., at 849 (citation omitted). This truism reflects the fact that there are legitimate penological interests served by regulating access, e. g., security and confinement. But concealing prison conditions from the public is not one of those legitimate objectives. Nixon v. Warner Communications, Inc., 435 U.S. 589 , decided this Term, does not suggest a contrary conclusion. The effect of the Court's decision in that case was to limit the access by the electronic media to the Nixon tapes to that enjoyed by the press and the public at the time of the trial. That case presented "no question of a truncated flow of information to the public." Id., at 609.