First, there is the chumminess of it all. Fry could be writing about the weather or swapping recipes for Battenburg cake, but he isn't. What he is talking about is something that lies at the heart of the Bloomsbury aesthetic, namely the cult of personality. Not for nothing was the Bloomsbury Group's defining text dear old Lytton's Eminent Victorians. Strachey's attempt to revolutionise biography by making it irreverent and bite-sized was new, but it was also solidly Victorian in its assumption that personalities mattered. Virginia may have disagreed with his methods, but she would have been behind him on that one. Above all, the personalities that counted as far as the inhabitants of Gordon Square and Charleston were concerned were their own: what Virginia had to say about Lytton, whether Duncan was sleeping with Vanessa or Maynard, and whether Roger and Clive knew or cared.
Something in Fry's letter suggests a paradox in all of this, though. The more incestuous (occasionally literally) the Bloomsburys become, the less there is any sense of intimacy in their work. Walk through the Tate's massive show "The Art of Bloomsbury" and you will see endless evidence of the physical companionship of the three main characters, Fry, Vanessa Bell and Duncan Grant. What you will also sense, though, is a curious lack of engagement in their pictures, not simply on a human level but on a painterly one.
This is especially true of Grant, whose flirtings with European modernism were the most promiscuous of the three. While Fry and Clive Bell philosophised about "significant form" - roughly, the idea that shape and colour in painting had a value separate from their representational function, a line of reasoning that headed towards abstraction - Grant was busy toying with everything from pointillism to Picasso. And toying is the word. The thoughtless grafting of Cezannesque brushwork on to Georgian form in works like Pamela (1911) will make the thin-skinned cringe; not nearly as much, though, as Grant's appalling Head of Eve (1912) in the Courtauld's show, as cack-handed a take on Cubism as you could never wish to see.
Somewhere in all of this, you may find yourself coming to think of the Bloomsbury Group's groupiness as being less the stuff of Merchant Ivory films than as either irritating or destructive. Although it is now unfashionable to analyse art in terms of biography, the self-obsessed dynamic of the Group's painters makes it inevitable that we should. It is when Grant is at his most Bloomsbury that he is at his most talentless; only when he manages to escape from Charleston or Gordon Square do we see the (very) faint flicker of insight. By far the most arresting of Grant's pictures in the Tate show are those that he produced while working for the Omega Workshops. Tellingly, these required him not simply to think in terms of function but to use manually laborious techniques - such as embroidery and collage - in making them. Set up Grant's easel on the Sussex Downs, by contrast, and the result is undiluted ennui.
In fact, the only member of the trio who seems to have been genuinely well served by the strangling closeness of Bloomsbury is Vanessa Bell. The claustrophobic nature of the Group's practice is all too evident in the number of identical subjects (artificial flowers, vases, the pond at Charleston) painted by all three of its artists. One pair of pictures does bear close inspection, though. Painted at the same time in 1914, Bell's Still Life on Corner of a Mantelpiece differs from Grant's The Mantelpiece in narrowing the subject's already narrow focus and lowering its viewpoint. Feminist art historians would see in this wilful embracing of confinement signs of a woman artist claiming domestic space as her own. You can't help feeling that they would be right. Grant's picture is a mess, aching to break out of both genre and picture-space by cramming in as many objects and styles as it can: a ludicrously male response to confinement that ends up feeling like Pride and Prejudice re-written by Thomas Hardy. Bell, by contrast, is happy to paint her portrait on Jane Austen's little bit of ivory. The essence of her picture is its reduction, representation whittled down to a simple interplay of colour and form.
In the end, you feel that this fetishising of smallness, the embracing of the cult of the narrow, was the only possible response to the Bloomsbury's togetherness. Whether (as it is now voguish to suggest) this means that Bell is actually a better artist than Fry and Grant, or merely a less bad one, is a moot point. Like its subject, the Tate's show is clubby. Its various sections are named after works by Bloomsbury writers and all the pictures in it are by Bloomsbury painters. See Bell's paintings next to a selection of, say, works by vorticist painters - never mind side by side with the odd Picasso - and your reading of things might be quite different. But then that would not be to play by Bloomsbury rules.
`The Art of Bloomsbury': Tate Gallery, SW1 (0171 887 8000) to 30 Jan. `Art Made Modern': Courtauld Gallery, WC2 (0171 848 2526) to 24 Jan. `Bloomsbury Portraits' display: National Portrait Gallery, WC2 (0171 306 0055) to 30 JanReuse content