Great Work: Iron Tree (2013), Ai Weiwei, 628 x 710 x 710, Yorkshire Sculpture Park, published in the Independent, London

Andrew Welford Photography

Last autumn, John Constable's small painting of the trunk of a great elm tree – so bulky and so vividly corpulent that it was almost huggable - shouldered its way into the space above such words as these. Here is another tree, this time captured on a sullen Yorkshire afternoon in springtime, on a day when the lapwings had just returned to their old nesting grounds in a nearby field. This tree is Chinese in origin, and it sits amongst English yews, in front of an eighteenth-century chapel, in a sculpture park.

Unlike Constable's, this tree is neither more nor less than a symbol. In common with so many of the works of Ai Wei-Wei, it proceeds by stealth. It does not sloganeer. It does not bang drums. His art is not so much an art of protest as an art of life-affirmation.

In part, it has the look of a tree. And in other respects it does not, not quite. It is, for example, a vivid orange tree – and by that I do not mean that it will in time be glad-handing the fortunate few with a crop of oranges. No, I mean that it is a rusting tree, in hue and actuality, and that it will continue to rust and to rust – it had the silvery sheen of new metal in 2013, when it was first put on public display inside that nearby chapel - until it becomes too dangerous for its own good. At which point it will suffer some equivalent of felling.

Yes, here we have a tree amongst old trees which is in fact a simulacrum of a tree. It consists of 97 separate parts, and each segment is cast in iron from a Chinese tree part. Its inspiration comes from street vendors of wood in Jingdhezen, Southern China. The whole is awkward, ungainly, fistily comical and wonderfully tenacious. In order to be itself at all, each limb or part-bole has had to be bolted and screwed together to every other part, as if it were a work of human manufacture. Which it is. The elements do not quite fit – one section of its massive trunk seems to be sliding sideways, drunkenly. The limbs gesture skyward, wildly, helplessly. Rivulets of rusting iron look as if they might just taste tangy. Its characterfulness also comprehends something rather nasty and even fairy-tale-cronish too.

We try to decide whether these are cast parts from one tree or many. We fail to reach a final conclusion. It is undoubtedly a tree of sorts, but this tree is also a message, we cannot but feel, about the condition of man in the world, this awkward, bolted-together creature who is forever striving to cohere as something credible and singular, forever striving to hold his own amongst more authentic versions of himself. Ai Wei Wei is by no means the first person of great imaginative reach to extrapolate from tree parts to the nature of the human condition. Read Jonathan Swift's great Meditations Upon a Broomstick, for example. At least this tree is the right way up.

Biography

Ai Weiwei was born in Beijing in 1957. In 1958, he and his family were exiled to Xinjiang, Northwest China, his poet-father having been accused of 'rightism'. He lived in New York from 1981 to 1993. On his return to China, he co-founded Beijing East Village, an experimental artists' cooperative. His passport was confiscated in 2014.

Great Work: Doge Loredan by Giovanni Bellini, National Gallery London, published in The Independent, London

He utterly dominates Room 62 of the Sainsbury Wing of the National Gallery, this steely-eyed man, just as he  would once have dominated the intricately vicious politics of Venice at the turn of the sixteenth century. I am speaking of Doge Leonardo Loredan, as depicted by Giovanni Bellini, in a painting said to have been executed in about 1501, the year that the Doge took office – an office he was to hold, unbroken, for the next twenty years of almost ceaseless warfare between the Republic and her many enemies. To call this portrait arrestingly magnificent is to sell it short. It is one of the greatest and most startling portraits of the Western canon, painted by a man, the greatest painter of an entire family of remarkable painters, who was at the heart of the political and cultural life of Venice for the duration of his long life – Giovanni Bellini finally died in 1616, aged 86.

I have a crude rule for testing the worth of any work of art. It is called the Ten-Second Test. If any work of art is worth staring at for as long as ten seconds, it stands a chance. That’s it. Most works of art – and especially those which are being made today under the name of ‘art’ – fail that test miserably. Three seconds, perhaps four, are quite enough. To apply such a test to this portrait of the Doge would be laughable in the extreme. The more you stare at it, the more you become absorbed into the marvellously unsettling richness of its ambiguities. There is the test, you see: this work is inexhaustible. The more you look at it, the more it seems to say to you. In this respect, it resembles a great poem.

Surprisingly for a secular portrait, the Doge is not in profile, but face-on (well, in fact, just slightly askance) to the painter and the onlooker – this face-on mode of depiction, for most of the Middle Ages, was generally reserved for sacred portraiture. Now a Doge, a mere mortal man, has been given the treatment once reserved for sacred subjects. And yet this man was not a king, and even less an absolute monarch - and we sense and feel this from the way in which Bellini has painted him. Monarchs more often than not look like over-stuffed balloons. They have little characterful reality, little genuine solidity. They are little more than the majestic way in which they are being represented. Think of Van Dyke’s ridiculous portrait of Charles I on horseback, for example, recently on display at Tate Britain, galloping towards us like a bewigged crazy on a pantomime horse, or of Goya’s glittering dismissals of the Spanish Royal Family whose court painter he was paid to be. More fools them! These paintings, for all their visual splendour, are often nothing but gloriously laughable pieces of puffery. They are lies.

The Doge, on the other hand, is at least two things at once. He is a human being spectacularly adorned in the vestments of his office – gorgeously brocaded mantle worked over, in gold thread, with pineapple motifs which we can see upside down; a ducal cap – known as a ‘corno’ (an allusion to its single horn) - worn over a linen skull cap - but he is also the brutally focussed man that he needed to be in order to negotiate his way through the diplomatic challenges of being Doge of the Republic of Venice. This face is lean, wary, ascetic - almost to the point of revealing a slight tendency towards emaciation. A spiritual man then – but a spiritual man with an iron fist. It is the face of a master tactician, a diplomat. This is not a fat-faced Henry.

We are also a little surprised by the fact that the portrait is relatively modest in size – portraits of men of importance are usually as large as possible. This reminds us of the fact that the Doge was a man amongst men, elected by a committee of 41 aristocrats, perpetually subject to checks and balances; and a man, moreover, who earned relatively little from his official duties; who was not allowed to show favours to members of his own family; and whose rights to own properties outside the Republic was severely restricted. And yet his ceremonial functions were extraordinary – and this is why he is tricked out in such splendour, in robes of such brilliance.

But he ends mid-chest, and he stands behind a marble balustrade, looking out towards the Grand Canal or the Piazza San Marco (or, since the middle of the nineteenth century, towards rivals for his attention at London’s National Gallery), coolly appraising, almost rigid. Why is he cut off like this? Why is he not full-length? (By all accounts, he was not a short man so, unlike, say, Alan Ladd, he did not need to pretend.) Again, it is all to do with politics. The head-and-torso format of this portrait reminds us – and, I am sure, quite deliberately so - of Roman portrait busts. One great empire leads naturally on to another. It is also an attested fact that the Doge’s family believed itself to be the direct descendants of a Roman hero called Caius Mucius Scaevola.

I too am an hero, he is telling us, a servant of god, a master amongst men, within strictly defined limits, of course, which I not-so-humbly acknowledge.

 Giovanni Bellini (1530-1616) was one of the greatest of the Venetian painters of the Renaissance, whose subject matter encompassed sacred themes, secular portraiture and historical narrative. He pioneered the use of oil painting, and became celebrated for his tonal range and the richness of his colour.