Justice William Brennan, Keyishian v. Board of Regents (1967)

William Brennan

“[A]cademic freedom... is of transcendent value to all of us and not merely to the teachers concerned. That freedom is therefore a special concern of the First Amendment, which does not tolerate laws that cast a pall of orthodoxy over the classroom... The classroom is peculiarly the marketplace of ideas. The Nation's future depends upon leaders trained through wide exposure to that robust exchange of ideas which discovers truth out of a multitude of tongues, [rather] than through any kind of authoritative selection.”

Justice William Brennan, Keyishian v. Board of Regents (1967)