Tom Sutcliffe: The Titian that was no turn-on

I went to the National Gallery the other day, to look at the Diana and Actaeon, by Titian, that might be saved for the nation, and suffered the aesthetic equivalent of a sexual fiasco. Before I went into the room I was, I think it's fair to say, ready for congress – primed by various newspaper articles for an encounter with a great treasure of Western art whose departure from these shores would leave the national collection immeasurably damaged. In short, I was ready to be aroused and moved.

But in the event, I just couldn't rise to the occasion. Naturally, I was embarrassed. I can't honestly claim that this sort of thing has never happened to me before, but I usually manage to muster some kind of response, and Titian's Bacchus and Ariadne is actually one of my favourite paintings in the gallery. This time, though, nothing. And concentrating only made matters worse. Looking hard at Diana, trying to will a rush of blood into being, I simply found myself wondering about her unconvincing anatomy. Does that little head really go with that big body? And if so, how the hell is it connected?

I quite understand that the fault lies with me, not with Titian. In fact, I came away crestfallen. But it also made me realise that I've read a lot of vague assertions about the value of this painting in recent weeks, but very little in the way of specific persuasive argument. I should confess that I'm a national-patrimony sceptic anyway. We have a tendency in this country to become hysterical about a painting if there's a prospect of it being sold off to Johnny Foreigner, and then merely returning it to the obscurity it once enjoyed once the threat has passed.

But I'm certainly open to the idea that there is a great and unrepeatable bargain to be had here, given the Duke of Sutherland's offer of a discount first-refusal. What I haven't seen is the sales pitch itself, an account of this painting that goes beyond the suggestion that it would make our "set" better if we kept it. To protest that it would be "embarrassing" if the picture went abroad, as Tracey Emin did when presenting a petition to Downing Street, is to make an argument about national face-saving, not art. It's the fine-art equivalent of Pokémon, with Britain trying to hold on to a rare card. Blunt assertions about "beauty" and "genius" don't do much good either – they're just buzzwords to which we're meant to respond reflexively, rather than reflectively.

The closest I've seen to what is required are some remarks by Lucian Freud (before the picture came up for sale) in which he enthuses about its tumble of bodies. "Titian," he said, "does wonderfully what is one of the most difficult things of all to do, which is to paint people together. In a bad painting, the figures may be side by side, but are like butterflies in a book – there is no sense that they are really touching. But in Titian's paintings, even where ... knees touch each other, there is the most pleasurable sensation."

Reading that – specific, vivid, unpretentious – I actually thought it might be worth having another crack at consummation with Diana and Actaeon, and even, perhaps, chipping in to the purchase fund. We need more of that and less rhetoric if the public are to be persuaded to do the same.

Caution: truly bad ads about

I don't know whether it's the time of year or my advancing age but the IAI (Irritating Advert Index) seems to be particularly high right now.

There's that irresponsible toothpaste billboard which shows an apple with the word "Caution" stamped across it – idiotically conveying the message to Britain's carious soft-drink guzzlers that they should be wary of dangerous things like fresh fruit. Then there's the commercial for a new London shopping centre (above), which depicts potential customers as light-drunk moths, fluttering helplessly towards the flame of indiscriminate consumerism (although that, at least, can be defended on the grounds of inadvertent honesty).

But the highest IAI goes to the mystifying airline advert in which a shot of a foreign street scene is accompanied by the copy line, "You can't smell a city from a coach". As opposed, one assumes, to the evocative aromas that waft through the open windows of a 747.

It dawned on me that my daughter might be absorbing too much gangsta culture when, after her class had been doing Romeo and Juliet, she said: "Daddy, when we got to the line, 'Give me my long sword, ho!' I was the only one who laughed." I took it as a comment on my parenting skills and on Shakespeare's vulnerability to the flux of language. Given that the text has a hard time anyway with such confusions, I'm puzzled when directors add extra ones. In his new Lear, Rupert Goold has Edgar handing over a video as he says, "ope this letter", which makes Edgar look thick. Why not go the whole hog and have him say, "Check out this vid"?