All images: Michael Simpson, New Paintings, 2019, Installation View, BlainSouthern London, Photo Peter Mallet

I am at the National Gallery in London, sitting on a rich wooden bench in front of Johannes Vermeer’s A Young Woman Standing at a Virginal (1670–72). Outside it is grey and wet. Central London in autumn, choked with tourists in backpacks and cagoules. But here there is a certain calm in spite of the group visits and selfie sticks. The lighting is warm, neutral. People drift through the room, mostly in silence.

The painting itself is no bigger than a family-size box of breakfast cereal. It’s central third, taken vertically, is occupied by the eponymous maiden who we see from her head almost to the train of her gown. A little above the middle of the frame, her face is turned towards the viewer, smiling but in shadow.

According to the wall text by the picture’s side, this is “an idealised image of virtuous love.” But for Michael Simpson, speaking before the opening of his present show at Blain | Southern, a few minutes walk away off Oxford Circus, “it’s essentially a man locking together a series of grey rectangles.” The result, he tells me, is “almost as if he’s anticipating abstraction. It’s almost as if he’s anticipating the possibility of a world without representation.”

Simpson tells me he comes here “regularly” just “to see this one painting”. I’m reminded of Thomas Bernhard’s Old Masters, with its ageing music critic Reger and his almost daily pilgrimage to the Kunsthistorisches Museum in Vienna to sit gazing at Tintoretto’s White-Bearded Man. Is that why I’m here, now, myself? In the hope of catching Simpson in the act, to “observe him … undisturbed,” like Bernhard’s narrator Atzbacher, as he observes in turn his favourite Vermeer.

But there is no sign of Simpson here today. So I am left alone in the mid-afternoon crowd amongst hunched men with large cameras and too many pockets who suddenly shout, “Look at this one, Jean! It’s a JOE-hannes VER-meer!” And I am trying to see what Simpson himself sees, to perceive within this fifty-two by forty-five centimetre frame the subtle shift as “painting,” as he puts it, “moves beyond its subject.”

Curiously, it’s an old ploy of Slavoj Žižek’s I find myself falling back on. Somewhere in one of his shoe-box-sized digressions-from-talking-about-Hegel, the Slovenian philosopher suggests that one way to get to the core underlying meaning of a particular genre film is to try and reconstruct the plot without the central generic signifier – what would this horror film be about without the supernatural element or this sci-fi without the aliens and futuristic high-tech? In its own way, Vermeer’s Young Woman Standing at a Virginal is as generic as Friday the 13th or Star Wars. It is a domestic portrait, a scene of everyday life from the Dutch Golden Age. As conventional as you like. But take out the central subject and what are we left with?

Squares – overlapping and colliding in space, jutting forward or receding back – delivered unfussily in a wan, radically stripped-back colour palette.

The floor is a grid of black and white marble. The window to the left another grid of muntins dividing up the pane. The virginal itself no more than a box lurching forward like one of El Lissitzky’s prouns. And then there are the frames on the wall. Like Gabriel Metsu’s A Man and a Woman Seated by a Virginal (c.1660) and Vermeer’s own A Young Woman Seated at a Virginal(also 1670–72) which the National has chosen to hang either side of it, his Young Woman Standing by a Virginal features several paintings within paintings, one of which – the largest and most prominent, shows Cupid with his bow holding up what looks like another grey rectangle.

Even the young woman’s angular face is almost the same grey as the wall behind and this continuity is constantly threatening to collapse the depth of the painting’s perspective. The more I stare at it, the more I start to feel claustrophobic in the shallow space Vermeer allotted to his model. “Painting has to move beyond its subject,” Simpson had said to me. “And this is what I try to do in my own work.”

Born in Dorset at the start of World War Two, Simpson spent the early 60s at the Royal College of Art, a contemporary of David Hockney, Patrick Caulfield and RB Kitaj. When I ask him what he recalls of the time, he replies instantly: “girls.” But after a moment more adds that, “it was a fantastic time, the early 60s. You really can’t imagine what it was like. It wasn’t that long after the war and things were just beginning to happen. People felt free to say things that couldn’t have been said before.

“One of the things I remember most about the RCA,” he continues, “was Dave Hockney’s early paintings – which I still think, today, are some of the best things he ever did. He’s somehow got worse.” Simpson describes being in the mural room at the V&A with Hockney while the Bradford-born artist painted the “wondrous” A Grand Procession of Dignitaries in the Semi-Egyptian Style, “and I was making some wretched, crappy mural for the boys club at Bethnal Green, you know…

“But he did some great paintings then and the reason why they were so compelling was because he was coming out and he was finding that courage to do it.”

When I ask him if he thinks, despite their obvious differences, that there are still concerns that he and his RCA peers share, certain things that unite them as a generation of painters, his response is just as quick: “No.”

The subject – practically the idée fixe – of Simpson’s own work for more than forty years has been what he calls, “the infamy of religious history.” In his latest series of works, ongoing since 2012, that focus takes the form of leper squints. These hagioscopes, small, peephole openings cut into the walls of churches, were intended to allow those undesirables excluded from joining the congregation to watch the elevation of the host during services. As an architectural feature, they are the embodiment of a particular power relationship, embodying the binary division between ordinary worshippers admitted to the fold and those unfit to sit within God’s house but still subject to his rule. “A grotesque invention,” in Simpson’s eyes, “perhaps even more so than the confessional box.”

“The first time was in Dorset,” he says, “the first time I discovered a hole in the wall. I wasn’t even sure what it was. It was St. Aldhelm’s in Dorset – Studland – when I was a student [at Bournemouth College of Art, prior to joining the RCA] in the late 50s. But, you know, it took me years and years to find my own language before I could begin to use the squint and understand that there was potentially a kind of power in using these kind of grotesque religious symbols.”

It was, in part, “the added fiction of a ladder to reach the squint” that provided the key. By placing the hole in the wall itself just a little out of reach, accessible only by a rickety old step ladder, he exacerbates the grotesquerie to a point of absurdity. “The comedic element in all the painting,” Simpson says, “is very conscious – the whole idea of trying to climb this apparatus, to reach this point of looking through this squint but finding it extremely difficult to do so.”

Simpson’s squints have something rather coy about them – almost burlesque. They invite you to look while simultaneously refusing the viewer’s gaze, veiling the hoped for vision of transcendence with curtains and shutters and forbidding heights. Picture Malevich’s Black Square with a fig leaf over it. “It becomes a metaphor, as well,” Simpsons says, “for something that is essentially a hole into infinite space. And that is a reflection of bewilderment – my own bewilderment at the world around me, much of which I don’t understand at all.”

Talking to Simpson in person can be a disarming experience. In person, he has little of the smooth self-assurance that I have come to expect from artists represented by large, well-appointed Mayfair galleries. Immediately this endeared him to me, though he looked almost panicked when I pulled out my digital recorder. I had to sputter an excuse about poor shorthand skills. Throughout the interview, his eyes would dart anxiously towards the device as he spoke in exactly the manner that I will sometimes find my own gaze distracted by passing dogs. Later, listening back to the recording, I realised that along with Simpson’s words, it had captured the sound of him nervously jingling the loose change in his pockets.

“But having talked about subjective elements, I’m essentially interested in the mechanics of painting,” he says, changing the subject. So we talk about those ‘mechanics’ – the formal practice and technique of slapping pigmented liquids onto canvas. “Everything that you need in order to make a painting work on a flat surface.”

We talk about the role of size in his work (his canvases tend to be quite big). “I would never make a painting until I understand that the size of the rectangle exactly manifests itself in relation to the understanding of the idea,” he tells me. “I have actually made paintings that I’ve realised were half an inch out in one proportion and then I’ve had to start again.”

And is that because of the relation to the size of a human viewer?

“Yes. I wanted to make a painting that you could in a sense step into. But also I think I learnt quite a lot from [Fernand] Léger when I was a student. He painted his images right up on the picture plane. There. Against your nose.”

And we talk about the depth – or lack thereof – in his paintings. “It’s a very shallow space that I use,” he says. And even that meagre depth of field will tend to contain some element – like the greyness to the face of Vermeer’s virginal player – that threatens to collapse it altogether, lending his images “a kind of tension,” as he says, “which I do try and imbue the painting with.”

And we talk about colour. He brings up the last film of Pedro Almodóvar, a director I associate with a palette almost the opposite of Simpson’s own. “But there’s also a limitation to the colour,” Simpson insists, “an understanding of economy even though the key of the colour is high.” For his own part, he says simply that “the colour that I use is often related to the nature of the idea.”

And we talk about the way he paints, and where, about his studio space “in an old gasworks” and the way he likes “to work the palette some distance away from the surface of the painting. I like to hear the sound of my own footsteps going towards the painting and coming away from the painting,” and how the sound of those footsteps, back and forth from the canvas to the palette, becomes “in the most oblique way … musical.”

But if these are your real interests, I start to ask, the practicalities and technicalities of painting – its “mechanics,” as you say – then why have a subject at all? Why not make purely abstract images?

“Hmm…” he says. “Yes,” scowling slightly, “it’s an intriguing question. Because…” and he sighs heavily, “…part of me, for many many years, has thought about abstraction and I built up a certain kind of envy of painters who do not have to work with the tyranny of representation. But it’s in me. It’s part of what I am. The force of fiction in my imagination is really quite strong, I think. And I feel that you need something to work with.”

You need a subject, perhaps, in order to escape it, to move beyond it?

“Well, you begin with the idea of a squint, and with the added fiction of a ladder to reach the squint, however uncomfortable. But once the painting begins, everything else, the making, the subject, it all becomes subliminal. You just simply make the painting, given all the elements you have to make it in the first place. It’s a flat surface.”

We’d been talking quite a while and I start to say my thanks and prepare to go when with a sudden flash of warmth he asks me, “Are you interested in football?”

Regretfully – I don’t like to disappoint people – I have to admit that I’m not.

“Two reasons,” he says. One is that he is looking forward to watching a game with his son in the evening. And then he tells me a story about going to see a match, aged seven, with his uncle. He describes walking up into the stands and then looking down at the pitch from above at “this large green rectangle with different colours [the players themselves] moving around in it.”

Later, Simpson’s mother would tell him that afterwards he was often to be found sat on the floor, staring down at the carpet, arranging small objects in different formations, “bus tickets, anything with a bit of colour in it…”

“I had no idea, then, about ‘aesthetics’ – what it was or what it meant. But it was this occasion that instilled in me a fascination with colour.”

New Paintings by Michael Simpson is at Blain | Southern, London, until 16 November