Alison Watt’s latest artworks, A Portrait Without Likeness, asks exciting questions of portraiture, of seeing and knowing, in a way that excites David Robinson as he contemplates the book that accompanies the exhibition.

A Portrait Without Likeness
By Alison Watt
Published by the National Galleries of Scotland

You have to look really hard at Allan Ramsay’s portrait of Margaret Lindsay of Evelick, his second wife, before you realise that the rose she is holding in her left hand has a broken stem.  The rose itself, pink and fading, is facing downwards, the stem almost translucent: compared to the immediacy and directness of Margaret’s gaze at the viewer, neither of them seem to matter. Minor details only.

Alison Watt had looked at that portrait for years before she noticed the broken-stemmed rose. She knew it was important, because when she looked at the rest of his works, there it was again, in a preparatory red and white chalk drawing of a hand holding the rose, the fingers and flower at precisely the same, slightly awkward, angles, the light and shade mirroring each other in both preliminary drawing and finished painting.

What does it mean, this broken rose? Does it mean anything at all? Maybe it’s just Ramsay saying: ‘Here is my wife arranging flowers. She is putting the finishing touches to a bouquet that is just as beautiful as she is and is weeding out the one solitary imperfection.’

Or is he saying something more? On the note next to Ramsay’s portrait of his first wife Anne Bayne, at the Scottish National Portrait Gallery, we are reminded that all three of their children died in infancy before she herself died in childbirth in 1743. The note next to his second wife’s portrait points out that only three of her ten children with Ramsay survived childhood. Such a crushing weight of familial death surely demands a significant memento mori, so perhaps that was the real purpose of the broken-stemmed rose. But whose death? His first wife’s? (Would his second wife join in that mourning?) His lost children – yes, but from which marriage? Or all of them?

Two and a half centuries on, we can only guess. We can make up stories from these incidental elements in Ramsay’s portraits of his female sitters – Margaret Lindsay’s broken-stemmed rose, the book held by the bluestocking Countess of Balcarres, the cabbage leaf held by society hostess Frances Boscawen, the pink ribbon round Anne Bayne’s lace cap  – that may well be true, but we can never be certain.

Some people might find this lack of certainty irksome, but unknowability can be alluring too. In fact, it’s central to Alison Watt’s exhibition A Portrait Without Likeness, which ends next month at the Scottish National Portrait Gallery before transferring to Inverness Museum and Art Gallery (29 January-2 April). As she points out in the eponymous accompanying book the meaning of the broken-stemmed rose in Margaret Lindsay’s portrait, will always elude us – but that is not necessarily a bad thing: ‘It has come to represent for me the mysteriousness of painting itself.’

Because Watt’s 16 new paintings are all still lifes based on (but not copied from) details of Ramsay’s portraits of female sitters – an exquisitely worked lace handkerchief here, a quill pen there – the exhibition asks a series of intriguing questions about what we can ever learn from painting. To what extent, for example, do details in portraits – objects with which we surround ourselves in our daily life – matter? Can they deepen our appreciation of a portrait from the past? And – to get right to the heart of Watt’s work – does a portrait even need a face?

Apart from her exquisite skill with brush on canvas, one of the things I admire about Watt –  and it’s reflected in the book, the exhibition, and in her book festival interview with Andrew O’Hagan (check it out on edbookfest.co.uk – it’s still up there) – is the way in which she talks about Art without slipping into Artspeak. I’m sure you know what I mean by that – examples litter Private Eye’s Pseuds’ Corner and conceptual art exhibition catalogues – but only last month an enjoyable reminder came in Alexander McCall Smith’s 14th Scotland Street novel Love In the Time of Bertie. In it, portrait painter Angus Lordie reluctantly attends a talk at which a remorselessly trendy lecturer decries figurative art as ‘fixations of a stale mind located in a stale world-view’. ‘We no longer need paintings,’ he says, ‘we need experiences. We need ideas that spring not from the material but the inner experiential universe.’

Although the plot then takes a sharp turn towards the improbable – Edinburgh socialite nun Sister Maria-Fiore reveals that she has been appointed a Turner Prize judge – Lordie is cheered by the nun’s reaction to these heresies. ‘I found myself thinking who is the stale one here,’ she says, going on to blame conceptual artists ‘for saying the same thing over and over again. Whereas anybody now who paints in a conventional style is the radical, the outsider.’

McCall Smith hasn’t yet seen Alison Watt’s show, but if and when he does, I think he will find her work proves the truth of his characters’ observations. At the Glasgow School of Art, Watt told O’Hagan at the Edinburgh book festival, ‘I was deeply unfashionable because I was looking at 19th century French painting, which led me to spend most of my time in the life room. In my final year there were just the two of us in the studio, just me and the model, because it was being gradually phased out as a discipline.’

A classical arts education was, she says, ‘invaluable’ – but it hasn’t meant predictability. Just the opposite: having established herself early on as a portrait artist (the Queen Mother sat for her in 1989) and painter of realistic nudes posing on drapery, her whole aesthetic then turned away from the human form and towards the backcloth. She herself would argue that she still sees her work as figurative – even if the human figure is no longer in it.

Why isn’t it? I’ve never even met Watt, never mind interviewed her, but if I did, I expect she’d say that it doesn’t always need to be. That a work like Still, her huge quadryptych of white cloth (an empty shroud?) in the Warriors’ Chapel in Edinburgh’s Old Saint Paul’s Church would lose all its massive spiritual heft if it had even the merest hint of a body. That likenesses in portraiture might have nothing to do with what a person is really like.

And how do you show that anyway? You might capture a typical expression, you might even be able  to sum up some quintessential element of their character, but it won’t be all of their life, just one particular moment in it. But if what makes us us – the very thing the portrait painter is aiming for – is impenetrable, and the things we surround ourselves with aren’t? An artist can lift those objects out of time, drag them centuries into the future, and make us think about the humans who loved them in the past. It’s some trick, but in A Portrait Without Likeness, Alison Watt pulls it off.

A Portrait Without Likeness by Alison Watt is published by National Galleries Scotland, price £20.

As well as plates from the exhibition, it also contains an introduction and interview with Watt by Julie Lawson, an essay on her work by Tom Normand and a short story by Andrew O’Hagan. The exhibition at the Scottish National Portrait Gallery ends on 6 January and opens in Inverness on 29 January.