However poisonous the views of some citizens may be, freedom of speech is the ultimate test of a free society, insists Roy Harris
The need to restrict certain freedoms in order to protect other freedoms has long been recognised by political theorists as the paradox of the free society. What is in danger of being forgotten in the current rush of anti-terrorist measures, however, is that not all freedoms are on a par.
Freedom of speech takes priority over all others because without it the very concept of freedom itself is lost.
In a free society, universities have a primary duty to champion freedom of speech against all encroachments by legislators, pressure groups and trends in public opinion. Their academic responsibility is to ensure that the conditions for debate and discussion on campus of even the most unpopular or repugnant doctrines remain open. Banning certain speakers, teachers or organisations because of their views is a derogation of that responsibility.
Universities, in particular, have this duty because freedom of speech is required by freedom of inquiry, and such institutions would not exist in their modern form unless freedom of inquiry had been valued as the foundation of knowledge.
Why does freedom of speech have this unique priority? Our opinions are formed on the basis of experience, and that experience includes exposure to the opinions of others. But if others are not free to voice their opinions, we cannot reliably learn what they believe or why.
It follows that a society in which some are not free to express their opinions affords an impoverished basis for forming one's own. Where there is restricted freedom of speech, all judgment of social and moral issues is distorted by the enforced silence on banned topics.
In such a society, not only freedom of speech but freedom of thought would be an illusion. A collective mental warping of this kind is precisely what results when the advocacy of certain views is repressed for long periods by totalitarian regimes.
The major objections to recognising this primacy for freedom of speech fall under two headings. One is that the advocacy of certain views may, in certain circumstances, lead to action that involves doing harm to other people. Restricting freedom of speech is therefore allegedly justified to prevent such consequential harm.
The standard case is inciting a mob to violence. But this objection rests on a confusion of responsibilities. If I am persuaded by listening to a demagogue to commit an act of violence, the responsibility for the action lies with me, not with the demagogue.
The other line of objection is that, even in cases where no harm or disadvantage results, the expression of certain views may be deeply offensive to other members of the community. The standard case is the expression of religious or racial bias. Here, restricting freedom of speech is allegedly justified in the interests of eliminating hatred and promoting tolerance.
But these doubtless laudable objectives are not likely to be achieved by criminalising the speech of the intolerant. A free society is not one that can or should offer guarantees against prejudice, propaganda, criticism, antagonism or conflict. If you want such immunity, you do not want to live in a free society.
Is this just another ethnocentric argument? Does it have any relevance to societies that do not accept Western perspectives and values? Different societies do indeed differ in respect of the rights and responsibilities they recognise as regards various forms of social behaviour.
But those that place freedom of speech low on their order of social priorities have no convincing claim to be free societies at all. Before we enforce restrictions on freedom of speech as a way of defeating "extremists", we should ask ourselves whether we wish to join them.
Roy Harris is emeritus professor of general linguistics, Oxford University.