Freedom of speech isn't free

A number of Chinese poets and novelists have been ordered to confess to the sin of ''bourgeois liberalism'' and repent. A poem titled ''A Phantom Wanders Across the Great Land of China'' says heretical things, for instance, about the ironies of revolution: ''We shed blood and sweat, underwent great hardships, and thought we were building the great tower of socialism. But only later did we realize we had built yet another temple.''

Another dissident poet has written: ''The era of fervent beliefs is passed. Now is the era of confusion, a world of consumer goods and consumers.''

To Westerners, of course, these ideas sound eminently sensible. We find ourselves deploring, with no trouble at all, the censorship that would silence voices so vigorously and attractively at variance with Peking communism.

We invoke freedom of speech with no reservations when the country is somebody else's, especially when the heresy at stake happens to be close to our orthodoxy.

In the interests of historical fairness we must ask: How would our own impulses toward censorship look to the Chinese?

According to the American Library Association, the censorship cases in the United States have tripled within just a year, from about 300 in 1980 to 900 in 1981 already. John Steinbeck's ''The Grapes of Wrath'' and Alexander Solzhenitsyn's ''One Day in the Life of Ivan Denisovich'' have come under attack , and in Baileyville, Maine a federal court is scheduled to determine whether the school committee of that town is empowered to remove from the shelves ''365 Days,'' a 1971 account of the Vietnam war by Ronald J. Glasser.

In most instances the quarrel is not about politics but about taste. The books offend because of profanity or what is judged to be obscenity, usually with school-age readers in mind. Yet, despite their quite different grounds for fearing suspect writers, Chinese and American censors share a common dilemma. The general question comes down to this: How much harm may be done by an allegedly corrupting book, compared to the harm that will certainly be done by instituting practices of censorship?

It is not a simple question to answer when a book is specifically and profoundly repugnant to a reader.

A testing example is in the news these days. A year or so ago Robert Faurisson, an obscure professor of literature at France's University of Lyons, wrote a treatise maintaining that Anne Frank's diary is fraudulent - there was no holocaust, there were no gas chambers. The French government brought a civil suit against Faurisson on the charge that ''falsification of history'' is a crime.

A number of civil libertarians in France and elsewhere saw a danger in the prosecution, including Noam Chomsky, MIT's distinguished philosopher of linguistics.

Professor Chomsky has called the holocaust ''the most fantastic outburst of collective insanity in human history.'' Yet he finds himself being attacked almost as if he - a Jew himself - were condoning anti-Semitism rather than defending freedom of speech.

Attaching the very tricky concept of ''responsibility'' to the exercise of freedom of speech, the French courts found Faurisson guilty of a crime. To a civil libertarian like Professor Chomsky, a crime begins at the point of action, or direct incitement to criminal action; otherwise freedom of speech and thought should be absolute. A civil libertarian does not underestimate the inevitable relationship between ideas and deeds. He knows that his patience runs a high risk - waiting for the arsonist to turn his temptation into a lighted match.

But he sees no alternative, for he believes there is a higher risk to suppressing, even for the most impeccable reasons, freedom of speech. Who knows what case will come up next, once books are judged by the same rules of evidence as a knife slash in an alley?

One day one's own opinions may be banned. This is the ultimate hazard a civil libertarian keeps in mind.

''The real question,'' Professor Chomsky has told Boston magazine, ''is whether you believe in freedom of speech for views you regard as horrendous.''

What a hard criterion! No wonder we all harbor in the back of the heart the One Obvious Exception. Yet how many obvious exceptions - yours and mine - can we allow before restriction becomes our habit rather than freedom?

We may not always be able to avoid censorship, given such urgent excuses as national security. But, for the sake of democracy, we should never make it easy.