Florida, 309 U. S. 227, a judicial system which does not provide disinterested judges, Tumey v. Ohio, 273 U. S. 510, and discriminatory selection of jurors, Pierre v. Louisiana, 306 U. S. 354; Smith v. Texas, 311 U. S. 128.
A trial is not a “free trade in ideas,” nor is the best test of truth in a courtroom “the power of the thought to get itself accepted in the competition of the market.” Compare Mr. Justice Holmes in Abrams v. United States, 250 U. S. 616, 630. A court is a forum with strictly defined limits for discussion. It is circumscribed in the range of its inquiry and in its methods by the Constitution, by laws, and by age-old traditions. Its judges are restrained in their freedom of expression by historic compulsions resting on no other officials of government. They are so circumscribed precisely because judges have in their keeping the enforcement of rights and the protection of liberties which, according to the wisdom of the ages, can only be enforced and protected by observing such methods and traditions.
The dependence of society upon an unswerved judiciary is such a commonplace in the history of freedom that the means by which-it is maintained are too frequently taken for granted without heed to the conditions which alone make it possible. The role of courts of justice in our society has been the theme of statesmen and historians and constitution makers. It is perhaps best expressed in the Massachusetts Declaration of Rights:
“It is essential to the preservation of the rights of every individual, his life, liberty, property, and character, that there be an impartial interpretation of the laws, and administration of justice. It is the right of every citizen to be tried by judges as free, impartial and independent as the lot of humanity will admit.”
The Constitution was not conceived as a doctrinaire document, nor was the Bill of Rights intended as a collection of popular slogans. We are dealing with instruments