By Tom Rachman

New York Times News Service

“Free Speech: Ten Principles for a Connected World” by Timothy Garton Ash (Yale University Press, 504 pages, $30)

OXFORD, England — After the murders at Charlie Hebdo last year, the public intellectual Timothy Garton Ash — once a dashing foreign correspondent, long since a scholar amid the spires of Oxford — issued an appeal to news organizations: Publish the offending cartoons, all of you together, and in that way proclaim the vitality of free speech.

“Otherwise,” he warned, “the assassin’s veto will have prevailed.”

By this reckoning, the assassins triumphed, for most publications ignored his entreaty, to protect their staffs from danger or to protect their readers from offense. Elsewhere, different free-speech issues abounded: college campuses in convulsions over who should opine and how; tech behemoths pondering how to control (and profit from) the blizzard of online chatter; authoritarian governments snuffing out digital dissent.

Despite floods of online expression, free speech is on the defensive, Garton Ash argues, and he is trying to rally the resistance. He has established a multilingual website to seed tenets of free expression in nations where it is hindered. He travels the world promoting his ideals.

And now, he has written a scrupulously reasoned 491-page manifesto and user’s guide, “Free Speech: Ten Principles for a Connected World,” released in the United States last week, which includes his case for defying threats, his opposition to hate-speech laws and his view on whether another’s religion deserves your respect.

In an interview in his book-lined Oxford University office, this frosty-bearded 60-year-old professor of European studies sketched out his high ambitions. “What I want to achieve is to animate thinking and activism,” he said.

“It’s to catalyze a debate that starts from the basic principles of free speech,” he continued, “and then goes out and realizes them in many, many different directions.”

His own direction was set nearly four decades ago when, as an Oxford student, he traveled to Berlin to prepare a doctoral thesis on resistance to Hitler. Once there, he saw that the communist regime in East Germany offered a living illustration of totalitarian repression, and this became his new subject. The secret police took notice. (Their surveillance was the subject of his renowned 1997 memoir, “The File.”)

Expelled and denounced by the East German authorities for his writings — “one of the nicest reviews I’ve ever got” — Garton Ash passed the 1980s roving behind the Iron Curtain for publications like The New York Review of Books and The Spectator, chronicling dissident movements and befriending many of the main figures, among them Vaclav Havel and Lech Walesa. (He also has written for The New York Times.)

Then came 1989, a pivot point that included four seminal events for free speech: the fall of the Berlin Wall; the Tiananmen Square crackdown, which Garton Ash says presaged “the biggest censorship apparatus in the world today, arguably in human history;” the establishment of the World Wide Web; and the fatwa against Salman Rushdie.

Today, Garton Ash worries especially about echoes of the Rushdie case, writing that ceding to threats has become “a chronic weakness of free societies.”

“We as a society have to hold the line,” he said in the interview. “There has to be less appeasement.” For this, solidarity is required: Law-enforcement authorities must safeguard those who speak up, and taxpayers must be willing to pay the high costs this will incur. “Otherwise,” he added, “yielding to violent intimidation is itself objectively a kind of incitement to violence, right? Because you encourage the next guys to have a go.”

Not everyone agrees with his approach, especially regarding Charlie Hebdo. The award-winning investigative reporter and lawyer Glenn Greenwald, who has written extensively on transparency and civil liberties for the online publication The Intercept, scorns the idea. To defend another’s right to offend, he said, doesn’t mean you must join in that offense.

A concern nearer to Garton Ash’s office is what he calls the “I’m offended” veto, an especially contentious issue at universities, Oxford among them. Campaigners who espouse such positions argue that freedom from oppression sometimes outranks freedom of expression. The free-speech lobby, they contend, favors the mighty while sidelining the marginalized.

“To blithely assert that everyone enjoys the same right to free speech is like claiming that I have a right to buy a large house in north London because there is a ‘free market,’ ” the activist Paris Lees wrote recently in The Guardian. “Theoretically it is possible, but life in our real world isn’t like that.” She added, “Free speech isn’t under attack; platform privilege is.”

Liberal intellectuals such as Garton Ash, who have long taken pride in siding with the oppressed, find themselves in an uneasy position when disputing strands of this activism, particularly “no-platforming” (disrupting or canceling talks of speakers who are deemed offensive); certain cases of “trigger warnings” (flagging potentially distressing material before students can be exposed to it); and excessively defined “safe spaces” (mandating that colleges should protect students from upsetting experiences).

Regarding this last concept, the decorous historian Garton Ash came close to indignation: “Well, please. Give us a break.”

“What you do in universities is learn how to listen to and engage with views that you find deeply uncomfortable, distasteful, extreme, without coming to blows,” he said.

Garton Ash is not calling for any speech, anywhere. The discussion of free expression, he says, is always about where to place the limits. He advocates limits on speech that invades privacy; he opposes child pornography; he would protect certain official secrets, within narrow limits.

A vulnerability of Garton Ash’s project is that his principles are so deeply rooted in Enlightenment ideals, which are not universally shared.

In many places, audiences bristle when “a white Brit from Oxford,” he said, turns up to advise them on how society should express itself. Yet Garton Ash repudiates the notion that cultures such as those of China or the Islamic world are fixed, “like hydrogen, oxygen or granite or something,” asserting, “We should have a certain confidence in our beliefs and our values, but also an openness to this new world and to the conversation.”