Peter Ross: Planet Holyrood

ALEX Salmond has a mind like a steel trap in the body of a trapped seal. He rises, engorged and enraged, from his seat, front and centre of the Scottish Parliament's debating chamber, and barks angry yet articulate replies at whichever opposition MSP dares to provoke him. "Jeezo," says the man sitting next to me. "He speaks at a hunner miles an hour."

First Minister's Questions is a ritual enacted every Thursday at high noon, and tickets are booked months in advance. The late architect Enric Miralles designed the members' seating in a semi-circle in order to encourage consensus rather than conflict, but FMQs, as it is known, makes a mockery of this ambition. It is a fight, pure and simple. The MSPs cheer, jeer and sneer; the public gallery is packed with pensioners; and on the front row there's a school group from Falkirk who, strictly against protocol, clap and bang their feet whenever the Labour leader Iain Gray has a go at the First Minister.

"Everyone knows there's no such thing as a free lunch," says Gray, "especially when it comes to Alex Salmond."

This is a reference to the news that, at an event to raise money for the SNP's general election campaign, a lunch with the First Minister had been auctioned for 9,000, a figure which would buy you 3,913 portions of pie and beans or 16,364 Caramel Logs from the public canteen here. Personally, for nine grand I would want Sean Connery jumping out of a cake.

Later, Gray broaches the subject again, noting that while Scottish schools are struggling, "Alex Salmond is playing Celebrity Come Dine With Me". It's a good line if only because it raises the question of whom else might be on that particular episode with him. Susan Boyle? Frankie Boyle? The Naked Rambler?

But Salmond swats Gray away, and concludes by having a spat with David McLetchie, the Tory, on the privatisation of Scottish Water. Salmond is dead against it, which is welcome news for William Henderson, a pensioner from East Kilbride, sitting in the public gallery, looking smart in his grey bowling club jumper. "If that means I'll have plenty water for my whisky," he says, "that's fine by me."

First Minister's Questions is right before lunch, so you can enjoy the scrap and then go eat, or peruse the gift shop. "Is this the duty free?" asks one gentlemen, confused perhaps by the airport-style security at the entrance to the building. The shop does sell bevvy – Scottish Parliament-branded whisky – but is also the place to go for clootie dumplings, porridge spurtles and Harris Tweed iPhone pouches.

This is my first time in the Scottish Parliament, and inevitably I get lost. The building has been criticised for being out of keeping with Edinburgh's historic architecture, but it does reflect something of the city's disorientating higgledy-piggledy character.

The Old Town is an area of wynds, vaults, vennels, split-levels and sudden mysterious steps. The Parliament feels like that, too. It has its share of hidden corridors and staircases, and the huge number of windows and skylights mean you keep catching glimpses of unexpected beauty: the rugged angle of Salisbury Crags rising like a rainbow between two parts of the building; or a sullen huddle of hunched pigeons on the roof of Queensberry House.

This 17th-century home, incorporated into the Parliament, feels quite different from the rest of the building. Instead of smooth concrete, the pale grey of the Forth on an overcast day, here there are rough stone walls. In one it's possible to make out the shape of the archway which once led to the kitchen where, in 1707, while the Duke of Queensberry was out signing the Act of Union, his eldest son murdered, cooked and ate a servant boy. Puts "lunchgate" into perspective, that.

Despite this bloody history, Queensberry House feels much more calm than the rest of the Parliament, which can be manic, an Escher lithograph come to life. Here, too, is the Donald Dewar Room, containing books which belonged to the first First Minister, who died almost a decade ago. It's a solemn little spot, and fascinating to see the range of Dewar's library which includes his 19th-century family Bible, A Midsummer Night's Dream illustrated by Arthur Rackham, and a leather-bound history of the Jacobites in three volumes. Gratifyingly, there's also a Broons book.

The tremendous thing about spending time in the Parliament is that it affords an almost anthropological view of politicians. In the flesh, you can really get a good look at them. Jack McConnell, for instance, moves through the corridors of power with a sort of pimp roll, all hips and shoulders. Lord Foulkes is more of a scurrier.

Ever since she lodged a motion titled "AC/DC, We Salute You", I've had a soft spot for the Nationalist MSP Christine Grahame. So it's pleasant to spot her in the Garden Lobby and to be invited up to her room for a chat. Her assistant, a young Bulgarian man, is introduced, despite his protestations, as a spy.

Grahame's office is small. She has one of those "think-pods" – the window-seats Miralles designed as a space for contemplation – but never uses it. On her desk, taped to a lamp, is an object labelled Disposable Bullshit Bag. "But you'll notice it's empty," she says. "I run a tight ship."

I ask her to describe the atmosphere of Holyrood, which strikes me as cloistered and insular. "It's a bit of a bubble," she agrees. "If you come in here at half-eight in the morning and leave at eight at night, you're hardly mixing in with the public. When we were in the General Assembly building we had to come out of our offices and walk up the High Street to the debating chamber. So demonstrators could nobble you in the street. That was far better." Grahame is all about being accessible; she holds her surgeries next to the tills in Tesco.

In the Parliament's debating chamber, the public seating is directly above and behind the MSPs. From the press gallery you can peer down and contemplate the Rorschachian ambiguities of Alex Salmond's bald spot – does it really resemble the lion rampant? Not everyone is gripped by such things, though. "Kin ah go?" Ronnie McPhail, a retired forklift driver from Glenboig, asks one of the Parliament guides. "Ah huvnae hud a smoke fur four oors."

Outside, puffing away, McPhail looks up at the building he has just left. "To me it's an eyesore," he says. "I'm a traditionalist."

A guide had tried to tell him that the distinctive shapes around the windows are based on Raeburn's Skating Minister painting, but he's not convinced. Everyone's got their own theory about the windows and the guides have heard them all. Scottie dogs. Scalextric controllers. The Finnieston Crane. "One of the funniest ones I heard," says Hayley Forrester, who takes tour groups round, "was they look like Elvis's sideburns."

Billy Colquhoun, 64, is wearing a scarf in Royal Stewart tartan and a back-to-front baseball cap. He's running out the building to catch his bus, but has time to talk. "The place is brilliant!" he says, slapping my arm with glee. "See walkin' roond? You can see where every penny's went. It's been a real surprise to me. Totally different from seeing it on TV."

Almost six years after it opened, the 431 million building remains divisive. Even young architecture students aren't totally convinced by its symbolism. Elizabeth Clayton, 25, from De Montfort University, is walking round stroking the surfaces. Her nails are painted silver. "I think it's got great spaces," she says, "but I don't like the fact you can't interpret the meanings easily. You have to be told."

One very striking thing about the Parliament is how much contemporary art is on the walls. "Oh, there's an Alison Watt!" says Jean Girdwood, 64, here on a guided tour organised by Glasgow Women's Library. "I call this her flannelette period."

This group have brought with them packed lunches and a certain gallus spirit. "Level one please! Lingerie!" says Girdwood as the lift doors close. But they recognise the importance of this place and wish the younger generation took more interest in politics. "I worked with young girls who didn't know what suffragettes were," says Dorothy Bain, a 79-year-old from Clydebank in a black duffle coat. "That's something you should learn at your mother's knee. The suffragettes died for you. I get fed up hearing folk say they're not voting."

The main business of the day is the Marine Bill and when that passes almost everyone leaves. But around ten members remain, as the skylights grow dark, to hear the maverick MSP Christopher Harvie propose a motion paying tribute to the Scottish Railway Museum at Bo'ness and its founder, his friend John Burnie, who died suddenly in November.

Burnie's widow Ann is in attendance for what is a very moving debate. It's a reminder that politics isn't just to do with locking horns and legislating, or about the scandal of who had lunch with whom and how much they paid. Politics can and should also be about these small moments of civic-mindedness, these pockets of humanity and soul. It's never going to make the headlines, but Harvie's motion seems to get at the heart of what's really important about public life.

"I think," he muses, later, over a drink in the MSPs' bar known as the White Heather Club, "that the numpty count is not high around here." And – despite the strong contrary evidence of First Minister's Questions – I think I might agree with him.