Do artists see the world the rest of us see? Or are their works purely self-expression, with no tangible connection to historical reality? These questions might seem crude, the implied distinctions dubious. Clearly Vermeer, for example, captured something of 17th-century Dutch life, both the people and their houses. And although Italian Renaissance painters took classical and Christian mythology as their subject, an impression of their own time (clothes, faces, decor) does seep through in their work. Still, we would be unwise to deduce from a comparison of Corot and Courbet with Renoir and Monet that French life became more colourful - literally - over the 19th century. And if we want to know what the bombing of Guernica looked like, we are better off studying photos and newsreels than consulting Picasso's famous painting.
Yet the Picasso is no less "true", and conveys that truth more memorably and with greater emotional force than any newsreel can. As an artist, Picasso wasn't just selectively interpreting history (photographers and film editors do that, too), but painting what wasn't there - expressing ideas invisible to the naked eye and depicting emotions hidden from the lens. When photographers tamper with historical truth, they are liable to be accused of cheating; they can select, crop, compress and enlarge, but inserting faces that weren't present, or deleting bodies that were, will get them in trouble. Painters aren't placed under the same burden of representation. If the woman in the foreground needs a red hat because the structure and colour scheme demand it, then red it must be, even if the artist's model wore blue or the figure in the photographic image used as raw material isn't wearing a hat at all.
The greater freedom that painters enjoy doesn't mean they are unconcerned with authenticity, however. To think of painting as purely fictive, and photography as purely factual, does a disservice to both art forms. Martin Parr's undated photograph Jubilee Street Party, Elland, for example, is every bit as imaginative (and aesthetically shaped) as a painting would be. And the postures and expressions of the two women in John Bratby's Jean and Susan (1956) - clearly sharing some momentous secret - are no less true to life than any photograph. In their different ways, both Parr and Bratby convey something about British society and character. What they are saying cannot be reduced to a simple message but it is social observation nevertheless. Just as Charles Dickens saw things in Victorian society that other contemporary commentators missed, so the visual artists of our own time offer insights we can't find elsewhere.
If painting and sculpture have as much to say about the real world as photography does, what impression does the exhibition "Unpopular Culture" give of Britain in the years 1940-80? It looks a little grey, cold, wan, sludgy, down-at-heel, not bursting with imperial self-confidence but gently adapting to its reduced circumstances. Several of the human figures that appear are round-shouldered, as though bowed down by a sense of loss or depression. But there are cheerful faces to be found, too, taking refuge in drink, religious worship or familial comforts.
The nation appears to be predominantly urban, with cars, concrete, lamp posts, neon. But the countryside is still there, and its open spaces and wistful colours are quietly cherished, without brash celebration. Traditional entertainments persist - the seaside, the circus, fairs, pubs, fights - and the young are venerated, especially in photographs. It's not an affluent country, nor a fashionable one (there is little sign of the Swinging Sixties or the conspicuous consumption of the Thatcher years), but it is decent, public-spirited and doing the best it can. George Orwell would have recognised the place and applauded it.
Philip Larkin would have recognised it, too. In one of his finest poems, "To the Sea", he describes a visit to a seaside resort and marvels that its rituals are so little changed from those he knew as a child 40 years earlier:
Steep beach, blue water, towels, red bathing caps,
The small hushed waves' repeated fresh collapse
Up the warm yellow sand, and further off
A white steamer stuck in the afternoon -
Still going on, all of it, still going on!
Larkin published this poem in 1969, and it is interesting to compare it both with William Roberts's 1966 painting of the seaside, which portrays ten busy, interwoven, semi-naked, hulking éger-like figures, all with their backs to us, and with Tony Ray-Jones's 1967 photograph of Brighton Beach, which has a row of buttoned-up pensioners sitting, eating and staring into space. All three works delight in the persistence of humdrum, rarely celebrated leisure activities (or inactivities) at a time when they were thought to be disappearing. There's a sense of wonder (beautifully caught in Larkin's exclamation mark) that neither two world wars nor all the other upheavals of the 20th century have destroyed some essential continuities of British life. S Lowry's painting July, The Seaside, from a quarter of a century earlier, captures the same blithe spirit - immune to the threat of foreign invasion, our island nation disports itself by the sea.
Larkin is an obvious figure to invoke in the context of "Unpopular Culture", not just because Grayson Perry, the exhibition's curator, clearly knows and likes his poetry, but because it expresses the same unobtrusive elegance and nostalgia as the works in the show. Like many of his generation, Larkin saw the First World War and the arrival of modernism (whether that of Ezra Pound, James Joyce, Pablo Picasso, Igor Stravinsky or Charlie Parker) as a moment of rupture. In his poem "MCMXIV", he pinpoints that moment to 1914, des cribing men waiting to volunteer for military service and mourning the world that is about to be lost: "Never such innocence again." But for all his proclaimed hostility to foreign marauders and their dangerous experiments, Lar kin assimilated a great deal from modernism, as did most of the artists in this show. And for all his nostalgia, he continued to find pockets of uncorrupted innocence. I can imagine him poring over Homer Sykes's photograph Pinner Fair, Pinner, Middlesex: Whit Wednesday, not only because he enjoyed looking at naked ladies, but because quirky customs, time-honoured rites and ancient festivals appealed to him.
Larkin would also have been moved, for dif ferent reasons, by George Rodger's photograph of the aftermath of the German air raid on Coventry in 1940: Larkin had grown up in Coventry and two days after the bombing he returned there as a student from Oxford to make sure his parents were alive. Ruined buildings feature strongly in "Unpopular Culture", but newly constructed ones are here, too: a key feature of Welfare State Britain was the construction of blocks of flats for council tenants whose previous homes had been destroyed by German bombs or were deemed uninhabitable slums.
Usually thought to be the exclusive province of architects, buildings make a difficult subject for painters, but Michael Andrews and David Hepher, along with the photographer Christine Pearcey, rise to the challenge. Andrews is the most painterly: his Flats (1959) look partly Bauhaus and partly other-worldly, marooned as they are in a green landscape, with the odd black brushstroke hinting at a human figure. There are no people at all in the other two works. Hepher's is an oil painting of 1979-81 that aspires to both abstract expressionism and hyperrealism. Arrangement in Turquoise and Cream, he calls it, for though it looks like a photograph, what interests him is the use of colour and the formal constraint of a Mondrian-like grid. A garage door in the foreground disrupts the patterned severity to give a sense of scale. Pearcey also includes a low foreground building in her untitled 1973 photograph of a tower block, but for a different effect - the three violins hanging from a ramshackle corrugated-iron shed roof create a whimsical counterpoint to the soulless flats massing behind. All three artists are more interested in the formal possibilities offered by blocks of flats than they are in making social comment. But they do leave a visual record. This is what Britain looked like - still looks like. This is where millions live.
Other paintings in the exhibition have a similar representational impetus. Ruskin Spear's painting Hammersmith Broadway (1950), Frank Auerbach's Euston Steps: Study (1980-81) and Bryan Wynter's Landscape, Zennor (1948): real places in real time. But painting allows for mystery, too, and it's there in Elinor Bellingham-Smith's The Island (1951). Paul Nash's Promenade (1922) shows a severe concrete embankment but its grey and white shades are translucent and the woman walking along in an ankle-length dress is ethereal. Even the kitchen-sink realism of Jack Smith's After the Meal (1952) is deceptive: the setting is humble (bare floorboards and minimal furniture) but the crockery and cutlery seem to belong to another period and to a more elevated social class, and this gets the viewer wondering about the story and what the painting wants to tell us: why is the door open and what is the expression on the face of the girl in the background?
If the class affiliations of the art in "Unpopular Culture" are sometimes ambivalent, that is not surprising, as the artists came from a range of social backgrounds. The 1950s and 1960s were a period of greatly increased social mobility (more than exists today) and the effects of migration from one class to another were much debated. Larkin and his friends among the Movement poets (notably Kingsley Amis) were snootily derided by an earlier generation of writers for being "lower-middle-class". They also aroused the hostility of some of their own generation, who accused them of being "suburban". To this they replied that - irrespective of their origins - they were describing the reality of the Britain that they saw. Carel Weight's painting of a (north London?) suburban back garden in the 1970s makes the same claim. The World We Live In, he calls it, defying us not to recognise the houses, chimneys, leaves, straggling lawns, even the moustached figure in the foreground.
I suspect that Grayson Perry has called his exhibition "Unpopular Culture" for two reasons. First, he believes that a certain strand of British culture has never been given the attention it deserves, because written off as naff, ephemeral or self-effacing. Second, he is nostalgic for an age when artists had not yet become fashion icons. He might himself be a media celebrity, but on the evidence of his choices the art he values is introverted, unglamorous and more interested in exploring byways and backwaters than in parading itself on the global stage. He has said that he was drawn to ceramics because he considered it the underdog among art forms. And that same affection for the underdog is evident here - for art that is wholesome, truthful, textured and unflashy.
Anyone knowing only that Grayson Perry is a contemporary artist might have supposed the show would be full of videos, installations and self-conscious interrogations of "the meaning of art" (there are none). Someone knowing slightly more about him might have expected transvestism, pottery and images of Essex in the 1970s (there are very few). Instead, he has come up with a show that is muted, modest, wary, even at times slightly dour. A show that includes both the famous and the half-forgotten or relatively unknown. A show that is largely devoted to the period 1940-80 but allows in works from before and after that fit the mood. A show that explores the ways in which art adds to our sense of ourselves individually and as a nation. A show to get us looking and thinking.
"Unpopular Culture" is at the De La Warr Pavilion, Bexhill-on-Sea, East Sussex, until 6 July and then touring. For more information and tour venues visit: http://www.haywardgallery.org.uk