“There must be no barriers to freedom of inquiry … There is no place for dogma in science. The scientist is free, and must be free to ask any question, to doubt any assertion, to seek for any evidence, to correct any errors. Our political life is also predicated on openness. We know that the only way to avoid error is to detect it and that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think, free to think what they will, freedom can never be lost, and science can never regress.”
    Robert Oppenheimer

“The air of ideas is the only air worth breathing.”
    Edith Wharton

“I disapprove of what you say, but will defend to the death your right to say it.”
    Voltaire

“For millions of years, mankind lived just like the animals. Then something happened which unleashed the power of our imagination. We learned to talk and we learned to listen. Speech has allowed the communication of ideas, enabling human beings to work together to build the impossible. Mankind's greatest achievements have come about by talking, and its greatest failures by not talking. It doesn't have to be like this. Our greatest hopes could become reality in the future. With the technology at our disposal, the possibilities are unbounded. All we need to do is make sure we keep talking.”
    Stephen Hawking

“If Men are to be precluded from offering their sentiments on a matter, which may involve the most serious and alarming consequences, that can invite the consideration of Mankind; reason is of no use to us — the freedom of Speech may be taken away — and, dumb & silent we may be led, like sheep, to the Slaughter.”
    George Washington

“Discussion, therefore, is one of the motive powers of life, and, as such, is not to be deprecated.”
    John Tyndall

“Everyone has the right to freedom of opinion and expression; this right includes freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers.”
    The United Nations, Universal Declaration of Human Rights

“A mature society is one that reserves its moral outrage for what really matters: poverty and preventable diseases in the third world, arms sales, oppression, injustice. Bad language and sex might offend some, who certainly have a right to complain; but they do not have a right to censor. They do not have to watch or listen if they are offended: they have an 'off' button on their television sets and radios. After all, it is morally outrageous that moral outrage should be used as an excuse to perpetrate the outrage of censorship on others.”
    A.C. Grayling

“Religious apologists complain bitterly that atheists and secularists are aggressive and hostile in their criticism of them. I always say: look, when you guys were in charge, you didn't argue with us, you just burnt us at the stake. Now what we're doing is, we're presenting you with some arguments and some challenging questions, and you complain.”
    A.C. Grayling

“But such is the irresistible nature of truth, that all it ask, and all it wants is the liberty of appearing.”
    Tom Paine


“No right was deemed by the fathers of the Government more sacred than the right of speech. It was in their eyes, as in the eyes of all thoughtful men, the great moral renovator of society and government.”
“Those who profess to favor freedom, and yet depreciate agitation, are men who want crops without plowing up the ground.”
    Frederick Douglass

“The idea of the sacred is quite simply one of the most conservative notions in any culture, because it seeks to turn other ideas – uncertainty, progress, change – into crimes.”
    Salman Rushdie



“It is error only, and not truth, that shrinks from inquiry.”
    Tom Paine


“Give me the liberty to know, to utter, and to argue freely according to conscience, above all liberties.”
    John Milton

“The jaws of power are always open to devour, and her arm is always stretched out, if possible, to destroy the freedom of thinking, speaking, and writing... Be not intimidated, therefore, by any terrors, from publishing with the utmost freedom, whatever can be warranted by the laws of your country; nor suffer yourselves to be wheedled out of your liberties by any pretenses of politeness, delicacy, or decency. These, as they are often used, are but three different names for hypocrisy, chicanery, and cowardice.
    John Adams

“Our liberty depends on the freedom of the press, and that cannot be limited without being lost.”
“The only security of all is in a free press. The force of public opinion cannot be resisted, when permitted freely to be expressed.”
“Truth will do well enough if left to shift for herself... Truth is the proper & sufficient antagonist to error.”
“[I]t does me no injury for my neighbour to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg.”
“We are not afraid to follow truth wherever it may lead, nor to tolerate any error so long as reason is left free to combat it.”
“To preserve the freedom of the human mind then and freedom of the press, every spirit should be ready to devote itself to martyrdom; for as long as we may think as we will, and speak as we think, the condition of man will proceed in improvement.”
    Thomas Jefferson

“The strongest weapon against hateful speech is not repression; it is more speech...because, in the end, lies and misinformation are no match for the truth...Ideologies are not defeated with guns, they're defeated by better ideas...If you want a society that is free and vibrant and successful, part of that formula is the free flow of information [and] ideas, and that requires a free press. A free press is a foundation for any democracy...A great nation doesn't shy from the truth. It strengthens us. It emboldens us.”
    Barack Obama

“If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them.”
“If we thus admit that there is no authority beyond the reach of criticism to be found within the whole province of our knowledge, however far we may have penetrated into the unknown, then we can retain, without risk of dogmatism, the idea that truth itself is beyond all human authority.”
    Karl Popper

“If liberty means anything at all, it means the right to tell people what they do not want to hear...Threats to freedom of speech, writing and action, though often trivial in isolation, are cumulative in their effect and, unless checked, lead to a general disrespect for the rights of the citizen.”
    George Orwell

“In this country, I've been told, 'That's offensive' as if those two words constitute an argument or a comment. Not to me they don't.”
“One of the beginnings of human emancipation is the ability to laugh at authority. It's an indispensable thing. People can call it blasphemy, if they like. But if they call it that, they have to assume that there is something to be blasphemed, some divine word. Well I don't accept the premise.”
    Christopher Hitchens

Freedom of Speech discussion with Christopher Hitchens, Shashi Tharoor and Joan Bakewell 1:14:06

What are the limits of free speech? | Big Think 21:38

Big Think: Complete Transcript