Nothing Matters, White Cube, London

Lest you are newly back from Mars, something in the nature of a miracle has happened in British art: Damien Hirst has begun to paint.

Yes, I know about the Spot paintings, but Hirst's new works, on show at both branches of White Cube, were made, not by a fleet of assistants with spray guns, but by the artist's own hand and brush. This marvel has been met with all the hype his gallery can muster – Jolson Speaks! Hirst Paints! – so that you half expect Jay Jopling to hand out tots of restorative brandy as you emerge, dazed, from a visit.

And how amazing is all this? Well. Even if installation and concept have hogged the headlines for the past quarter century, I'd guess that something like 90 per cent of art made in Britain has consisted of painting. It was Hirst himself who led to the remaining 10 per cent being dubbed "Britart", as though there was no other kind. Much of the power of Hirst's work lay in its being anti-painterly, made by assistants, taxidermists and vitrine-builders. This was hardly new – Duchamp's readymades became Hirst's madebysomebodyelses – but something in the clinical nature of his art caught the public mood. In Hirst's work, the artist's hand became a metonym of the flesh and the flesh of mortality. Rid art of the hand and, vampire-like, it might never die.

So the insistent hands-on-ness of Hirst's new work is historically significant, whether you like it or not. And frankly, I don't. Who could? Underlying this work is the belief that you can, in middle age, take up painting and have the results shown at the most important contemporary gallery in London as if by right. And guess what? If your name is Damien Hirst, you can. But, other than as historical curiosities, will paintings made under such an assumption ever be worth looking at? Can they in any sense be good?

Let me say that "good" here is not another word for polished or skilled: Bad Painting, done well, has a solid place in 20th-century art. But there is Bad Painting and bad painting, and Hirst's work is the second.

In the ground floor space at Mason's Yard are canvases done largely in blue. Hirst's Blue Period – he has been painting for nearly two years now – echoes not so much Picasso's as Francis Bacon's, particularly the Savile-Row-blue images Bacon made of his lover, Peter Lacy, when he, like Hirst, was 44. Downstairs are Bacon-ish triptychs in Bacon-ish frames surrounding such Bacon-ish things as anatomised bodies and empty staircases.

Of course, Hirst has also made anatomical figures, most famously the 20ft bronze doll, Hymn. I suppose the frame of his trademark shark-in-a-box might explain the sketchy white lines, apparently lifted from Bacon's pope-cages, that score the surface of Walk Away in Silence – the shark jaws in Insomnia and Time Will Tell certainly refer less to Bacon than to a Bacon-like tendency in Hirst. And then there are the smaller (and, to my mind, better) paintings of the object with which Hirst is most closely identified as an artist, namely the human skull. Of all the works in this two-part show, Half Skull in Opposite Corner II, painted on newspaper laid on canvas, is the only one that lives up to Hirst's earlier fame, that makes you hope he will stick to his brushes.

All of which raises a great many questions, the most obvious of which is why? Hirst, with his vitrines of flyblown meat, has always been a Baconite. Why does he now feel the need to work like Bacon? A triptych called How Did We Lose Our Way? may suggest an answer. Bacon died mid-way between Freeze and Sensation, the two shows that made Hirst's name. Could the younger man's return to paint on canvas mark an admission that the Britart experiment has, in the end, been a failure? Seen like this, the dreadfulness of Hirst's painting might be excused as intentional, a sign that something has been lost in British art and that that loss is irreparable.

I certainly prefer this possibility to the other, which is that Damien Hirst feels he can paint by dint of being Damien Hirst. This, appallingly, is not the case. I went to White Cube determined not to fall into the British trap of thinking that artists can only do one thing well, that installationists and conceptualists can not also be painters. Look at Michelangelo. I left with a sense of sadness that a man whose pills and diamond-covered skull will remain icons of his time should have been laid so low.

White Cube, London N1 and W1 (020-7930 5373) to 30 Jan 2010