John Quinn is a mighty man, to coin a phrase. Dwarfing a radio studio, really dwarfing a radio columnist, he's attractive in that way reserved for large men - particularly those who carry their height easily and speak softly. Quinn doesn't throw his weight around, but his stature is unquestionable.

At last week's launch of The Open Mind Guest Lectures 1989- 1998, edited by Quinn, someone made the mistake of suggesting that, with his myriad interests and talents, the veteran broadcaster was "too good for radio".

With an understandable parochial interest, but with no less honesty and passion for all that, RTE's director of radio, Helen Shaw, had a response to the comment: "Nothing, but nothing, but nothing is too good for radio."

Quinn has made his mark in other areas, but his special gift, his magic, is as a maker of radio programmes: interviews of rare clarity, sympathy and sophistication; documentaries of extraordinary atmosphere, perception and narrative grace. Age 58, Quinn is 25 years in RTE now, having previously enjoyed a vocation as a teacher. Needless to say, he has acquired a few opinions about radio in that time; it's obvious he has been in no hurry to present or produce a telephone-driven programme such as Liveline, to be sure.

The first programme he produced was Knock at the Door, a children's show: "It's sad there's nothing for children on radio now," he says. It's not surprising to hear this from a successful and passionately committed author of children's fiction, but as he describes the dangers of the underdevelopment of genuine listening skills, with active input from the listener's imagination, it seems he's not only talking about children.

Nonetheless, his respect for his colleagues is evident. And the respect he has earned for himself in that quarter-century with the national broadcaster means he's quite free to do his own thing. The Open Mind is very much his own. "I had a laugh there recently when someone referred to `John Quinn and his team'. I am the team."

The same goes for his other work. His next documentary will profile a top London chef who hails from Quinn's now-familiar home place of Ballivor, Co Meath. (Generations to come, armed with no data except Quinn's programmes, will be able to construct a coherent social history of that village and its environs in the mid-to-late 20th century.) All that's involved is Quinn hopping a flight to London with his DAT recorder and a good stereo microphone.

The cost over and above his modest-enough salary and the wear-and-tear on the equipment will be a few hundred pounds - dear enough by Quinn's standards. If past work is anything to go by, it will paint more vivid pictures than many $100 million movies.

It also moves his Ballivor opus distinctly into the present day. "I'm wary of the word nostalgia," he says. His oral-history documentaries are "not sweet and lovely and weren't we great". For anyone who has listened to A Day on the Bog, his beautiful documentary, which essentially stuck a mike at Johnnie Kelly and heard the life and lore of this Meath "bogman" and the bogland, it's impossible to disagree with Quinn's words: "It's important to put these things on the record." All the more so when Kelly died not long after the programme was first broadcast.

The Open Mind, he points out, is "forward-looking". This show, on Thursdays at 7.05 p.m., is a weekly victory for considered, ideas-driven radio over any dumbed-down formula. It's mostly composed of interviews done with people Quinn chooses; its original, educational brief has widened, and thinkers of all sorts have found themselves chatting, with listeners often treated to more than one programme featuring the likes of Brazilian social-theatre activist Augusto Boal, or (a Quinn favourite) Charles Handy, a guru of organisational change.

The contributions to The Open Mind Guest Lectures record the range of the programme's interests over the past decade - from Michael Cuddy's still-timely 1991 lecture on rural Ireland's future to Michael D. Higgins's 1993 thoughts on "education for freedom" and Anne Fine's 1996 reflections on the importance of books. And there, too, are Gordon Wilson, John Hume, George Mitchell.

Like Quinn's documentaries and his 1995 novel for adults, Generations of the Moon - a family saga of sectarian strife along the Border from 1925 to 1975, and a passionate plea for peace - their presence reflects Quinn's profound interest in the state of Ireland.

"I love it," he says, simply - he's a man who can refer to "the old sod" without sneering. "I love the wonderful, extraordinary ordinariness of its people. I love who we are, the way we are, the way we use language." Quietly he says: "The threshold we're standing on at the moment is so important."

A patriot, then? "That's another old-fashioned word," says Quinn (who has already admitted his Luddite approach to all his writing: biro only). "I'm not a patriot in the narrow sense - chest thumping, give-me-a-gun-and-I'm-off - but in the best sense of the word: love of fatherland."

With these concerns, his literary bent, and having memorably interviewed Heaney on more than one occasion, Quinn is the obvious man to organise Heaney Moments, "six or eight items of Heaney" - poems, personal milestones and the like - "that will be dropped in all over the Radio 1 schedule" on the poet's 60th birthday, on April 13th.

Quinn sits over a cup of tea in the radio-centre canteen - "some of the best programmes are really made in here, maybe with someone saying to you `there's someone you should interview now'." Lighting and re-lighting his little cigars, he can't quite shake off a slight aura of chaos, of too many projects and ideas bouncing around in his head and across his desk - and of some frustration at the time it takes to bring them (especially the literary projects) to fruition. But Quinn, even as he's describing the joy of a late night in the studio, denies the "workaholic" label stuck on him by as keen an observer as his own wife.

"It's wonderful," he says, "to be paid and supported for doing stuff you love doing." If the hours are long and the commitment total, that's because "I love my work. In fact, I love everything I've done".

He'd want to be mad, he suggests, not to enjoy the work he has been doing - "dealing with Seamus Heaney, Charles Handy, Johnnie Kelly. It's a wonderful life."

It's a Wonderful Life. Starring Jimmy Stewart, with a bit of padding, as John Quinn? No, not quite: Quinn's a big, gentle, unpretentious man all right, but he's also got a bit of the auteur about him, the crafter of affectionate, deceptively simple, populist works about the people and places he loves and seeks to understand more deeply.

So is John Quinn actually Ireland's answer to Frank Capra? Nothing, but nothing, but nothing is too good for radio.

The Open Mind Guest Lectures, edited by John Quinn, is published by the Institute of Public Administration and Radio 1, £12 in paperback.