"The most effective censorship is not, in fact, legal; in a democracy—as Tocqueville pointed out in Democracy in America—it is public opinion."

“With the Sedition and Espionage Acts … the "red hysteria" of the Twenties, the Alien Registration Act of 1940, the loyalty tests and purges of the mid-Forties, the establishment of un-American Activities Committees, intolerance received, as it were, the stamp of official approval. Loyalty was identified with conformity, and the American genius, which had been experimental and even rebellious, was required to conform to a pattern.”

“We are shocked when we see educators, timid before criticism and confused about first principles, betray their trust. And we wonder what can be that 'philosophy of education' which believes that young people can be trained to the duties of citizenship by wrapping their minds in cotton wool.”

“The greatest danger that threatens us is neither heterodox thought nor orthodox thought, but the absence of thought.”

“Who are those who are really disloyal? Those who inflame racial hatreds, who sow religious and class dissensions. Those who subvert the Constitution by violating the freedom of the ballot box. Those who make a mockery of majority rule by the use of the filibuster. Those who impair democracy by denying equal educational facilities. Those who frustrate justice by lynch law or by making a farce of jury trials. Those who deny freedom of speech and of the press and of assembly. Those who press for special favors against the interest of the commonwealth. Those who regard public office as a source of private gain. Those who would exalt the military over the civil. Those who for selfish and private purposes stir up national antagonisms and expose the world to the ruin of war.”

“A nation that silences or intimidates original minds is left only with unoriginal minds and cannot hope to hold its own in the competition of peace or of war.”

“We should not forget that our tradition is one of protest and revolt, and it is stultifying to celebrate the rebels of the past—Jefferson and Paine, Emerson and Thoreau—while we silence the rebels of the present.”