Arguably the doyen of this dubious (but never doubting) profession, Johnson dislikes being described as prolific (though he is). "It implies huge quantity and very little quality," he sniffs. His nostrum for column-writing is simple: "Get your argument straight and the words will come pretty easily."
His views, agree with them or not, come from a lifetime of study and application. "The most important thing is reading. I've got an extensive library in both my residences [in Bayswater, west London, and Somerset]. Bacon really got it right: reading maketh the full man.
"People sometimes say that a journalist can't be a historian and vice versa, but the two pursuits fit very well. Knowledge of the historical origins of contemporary problems and divisions helps you enormously when commenting upon them."
He has written more than 30 non-fiction books in the past 40 years, including A History of the Jews, a History of Christianity and Modern Times: A History of the Twentieth Century. He believes the most successful campaign he has prosecuted was in favour of trade-union reform, a cause he pushed repeatedly in a number of publications from the late Sixties until the election of Margaret Thatcher (who needed no encouragement in this sphere).
Though he is a Roman Catholic, with views of extreme conservative moralistic righteousness, at least one of the columnists he most admires is at the other end of the attitudinal spectrum - Polly Toynbee. "She doesn't just witter on like a lot of other women columnists, but does her homework. I'm proud of having published her first article, when she was 18. I also find Alexander Chancellor very entertaining. And my old friend Perry Worsthorne has been enjoying a new lease of life since he left The Sunday Telegraph."
MARY KENNY, The Express, Sunday Independent (Ireland), The Irish Catholic
"A columnist really needs to have a worldview, a Weltanschauung, and that can only be acquired through personal experience plus voracious and extensive reading." The Kenny Weltanschauung has changed somewhat over the years - she was once a fiery feminist with radical views; she is now a Roman Catholic moralist and, among other things, a fierce critic of what has happened to her native Ireland in these post-Catholic times.
Though hardly wanting in forthrightness, she does not feel that age and wisdom are necessarily friends of the professional opiner. "You can lose your voice as a columnist as you get older. For you see the world in a far more nuanced way. You see the complexities and contradictions, which can make life difficult when you try to rattle out a forthright argument."
The opinions she respects most are those of specialist writers. "I'd welcome more specialisation in journalism, people who are both authoritative and accessible," she says. "We're drowning in information and are so short of intelligent interpretation.
"I often think that a lot of what I write doesn't matter much, but sometimes I find myself addressing a ladies' lunch and women will come up to me afterwards and say: `Remember you're very influential.'
"Kevin Myers writes a brilliant column in the Irish Times. It can be terribly funny at times, but he also has a real sense of mission: he really believes killing people is awful. Can't say I enjoy his column in The Sunday Telegraph as much."
ALLAN MASSIE, Daily Mail, The Scotsman, Sunday Times (in Scotland)
That your views prevail is far from the only criterion of success for a columnist. The Scottish novelist and polemicist Allan Massie has been arguing against Scottish devolution for the last two decades in a range of newspapers and magazines on both sides of the border.
"I've been writing against the grain of Scottish opinion and I cannot say it has made a blind bit of difference," he reflects. "Then again, people come up to me frequently and say, `Well done, I've been waiting for someone to say that.' "
His advice to would-be opinion columnists: live in the country if you can, stay at home and keep in touch with lots of people by telephone. And when you're struggling to put your thoughts down on paper, force yourself to write the first sentence.
Agreeing with a columnist is not the criterion for admiration: "I disagree with Paul Johnson nine times out of 10, but when you start reading one of his things you tend to go on. I also admire two Irish commentators, Kevin Myers and Ruth Dudley Edwards, who have shown a rare courage by writing against violent republicanism. And of course, Conor Cruise O'Brien, who was the first to do that."
JOHN LLOYD The Times, New Statesman, Scotland on Sunday, Prospect
Having spent most of his career on the Financial Times, John Lloyd's natural inclination is to be cerebral and analytical rather than outspoken and outrageous. "At the FT one has a great determination to be balanced almost to the point of parody. A lot of arguments tend to end: `On the other hand, perhaps not ...' "
As for other columnists: "For over 30 years Hugo Young has been a clear, liberal voice, who can also be passionate at times. Another Westminster commentator I increasingly admire is Don Macintyre [of The Independent], whose liberalism is different from Hugo's. On the conservative side, Simon Jenkins is sharp."
SIMON JENKINS The Times, Evening Standard, Country Life
When he mounts his secular pulpits in The Times or in the Evening Standard (and even in Country Life), Jenkins sees himself as following in the footsteps of his father, who was was a preacher.
"Columnists, like preachers, have to feel they make a difference," he says. "And they probably do. Because penning 1,400 words of opinionated prose each week provides much more public exposure than any politician gets."
Among his favourite hobbyhorses are non-intervention in foreign affairs, the need for localism in politics and a mayor for London, the last of which seems to be at last bearing fruit. "A measure of repetition is a good thing since coming back to themes shows you care," he says.
"The columnist I've always found most inspiring is Bernard Levin. My other two favourites are Matthew Parris and Alan Coren, who make me both laugh and think."
MARY RIDDELL, The Mirror, New Statesman
"Ideally you've always got to write about something you're actually bothered about," she says. "It's dangerous if you start adopting positions simply to get people's backs up." And, she adds, don't become a Rent-a-Rant.
"Robert Harris used to provide an interesting perspective in the Sunday Times before he went back to novel-writing. I also like Simon Jenkins very much, plus Polly Toynbee and Melanie Phillips. And Matthew Parris has a nice levity."
SIMON HEFFER, Daily Mail, New Statesman, Country Life
"To be a good columnist you do have to have strong views one way or another and they have to be based upon sincere beliefs. Paul Johnson is a magnificent columnist. He gets really fired up about things and isn't indifferent about anything. Plus he has a great ability to articulate his passions. I also like Anne Applebaum."
The triumph of Hague in the Tory leadership race, says Heffer, will be "very good for trade. I can't believe they have picked a boy to do a man's job. He's going to be a disaster, just like John Major. I made a lot of money out of Major."
POLLY TOYNBEE, The Independent, Radio Times
Recently judged "Commentator of the Year" in the What the Papers Say Awards, she believes that columnists can have a galvanising effect and even occasionally shift government policy a bit when they draw attention to a development which has gone largely unnoticed.
"We have to bring added value to an argument in terms of information people don't already have," she says, pointing out that the commentators she likes least are those on the tabloids who spout off on a range of subjects they know little about. "It is totally naff just to add your opinion on major events of the week. Doing a specialism is a good preparation for becoming an opinion journalist. In my case it was social policy and I return to it often in my columns.
"I admire Simon Jenkins, who knows a lot about a lot and is good at imparting his knowledge. My Independent colleague Suzanne Moore is the best of the women commentators."
MATTHEW PARRIS, The Times, The Spectator
A former Conservative MP and presenter of Weekend World, he doesn't think that opining matters much. "It makes no difference at all, never changes anything," he says. "It's just entertainment for readers, who make up their own minds.
"Yes, I'm a complete media tart," he whimsically declares. "Editors, programme producers and all who commission written and broadcast work in Britain are extremely lazy. Whenever they want a certain opinion expressed, they just turn to an established list. My advice is get published in six places and another 66 will want you.
"There are a lot of people who write well, but I particularly like Libby Purves who writes well and is also thoughtful."
ANNE APPLEBAUM, Evening Standard, Sunday Telegraph, New Criterion (US), New Republic (US)
"Be a reporter initially as the best columns are based on reporting experience as well as ideas," she advises. A young American who gained the attention of British editors by reporting on the fall of Communism in Eastern Europe for The Economist and then The Spectator, Applebaum is now associate editor of the London Evening Standard. She writes mainly about British politics for publications on both sides of the Atlantic.
"I don't really have many friends among British politicians, and I want to keep it that way," she says. "In general I'm an outsider, writing from a slightly odd perspective."
She admires as columnists Simon Jenkins and Andrew Marr, "even though I disagree with them frequently."