Velazquez, Diego : An Old Woman Cooking Eggs (1618)

"What vanity painting is," wrote Blaise Pascal, "attracting admiration by its likeness to things of which we do not admire the originals." It is a sharp putdown, and it's typical of its author. A hard-line puritan, Pascal had a keen eye for the ways that humans distract themselves from the emptiness and brevity of their lives. Painting is one more example of our fatal talent for diversion.

Still, the thrust of Pascal's remark is slightly ambiguous. He might simply be saying, like various high-minded art critics of his time, that painting is worthless when it devotes itself to the depiction of worthless subjects - things such as vegetables or the lower classes.

But probably he intends a more sweeping rejection. All representational painting is a worthless pleasure: what we admire about it is likeness for its own sake. The proof is, we value the achievement of a likeness, whatever it's of - even a likeness of things we don't have any regard for. So painting is just a pointless exercise of skill, a way of gratuitously adding interest to our lives.

Of course, you may protest that Pascal has got painting wrong. Even when it does create a likeness, it's not the likeness itself that attracts our admiration. What we admire are other, finer things - the composition, the expression, the vision etc.

But it must be said that, in his own day, Pascal's premise was not eccentric. He was attacking art on its home ground. Many artists of the 17th century would have agreed that the "imitation of nature" was the chief business and excellence of painting.

And even today, when we look at 17th-century art, we may have to agree. Never mind all the other stuff, the sheer realism of it is what takes your breath away. So perhaps Pascal's challenge still touches a nerve. What exactly is so worthwhile about a likeness? It's a question to ask, for example, when you're looking at the early work of Velazquez.

Diego Velazquez painted An Old Woman Cooking Eggs before he was 20 years old. It is clearly a demonstration piece. Everything is on display. The contents of the scene are laid out around the canvas like decorations on a Christmas tree. Let the eye circulate, checking each thing off: melon, glass flask, wooden spoon, terracotta pot, brass pan, egg, china plate, red garlic, brass mortar, red onion, earthenware jugs, tin dippers, woven straw basket, linen cloth.

One of the advantages of high-contrast lighting (as introduced by Caravaggio, 1571- 1610) is that a painter can decide exactly what a picture shall show, while still keeping the scene realistic. There's no obligation to put in all the details of the setting. Whatever you want can catch the light - and everything else can lapse into more-or-less plausible darkness.

Velazquez uses his darkness to select a limited cast of objects, and to single each one out, separate and luminous. The eye can attend to each in turn, notice how they've been selected for variety of texture, and admire Velazquez's mastery of different kinds of reflectivity. The picture is a parade of gleams - onion skin, polished brass, glass and liquid froth. The star of the show is the twinkling, fractured dazzle on the glazed terracotta. It even upstages the amazing spectacle inside the pot, the two simmering eggs, with their spreading skirts of albumen caught just on the brink of opacity.

Among these things, a couple of humans lurk. But the boy and the old woman are not exactly active, and it would be misleading to call this a kitchen scene. It is a life painting, with two people holding stationary poses among a collection of inanimate objects. With respect to these objects, they seem to be ancillary. Their role is not to use them, but to hold the mup and display them- as well as to be two more objects themselves, two more examples of texture, human flesh old and young, two more opportunities for bewitching depiction.

There's no doubt that sheer realism is a large part of the wonder here. The eye dwells in amazement on each object rendered. But amazement at what precisely? At the objects themselves, revealed in all their glorious particular thinginess, or the artist's superlatively skilful rendering of them?

You could put the question more sharply. Velazquez's subject matter here is obviously "low". Nowadays we love gritty everyday life. We take it for granted that everything is worthy of art, that there are no ignoble subjects, and that truth is generally rough. But to Velazquez's contemporaries, his choice of subject would have been a pointed statement. Some would have seen the contents of this scene as base and unworthy of regard. Others might have enjoyed the challenge. No one would have been blind to the hierarchies of taste. Velazquez himself said at the time, "I would rather be the first painter of common things, than second in higher art."

So the sharper question would be: is Velazquez using his abilities as a painter to draw attention to these "common things"? Or is he using "common things" to draw attention to his abilities as a painter? Is this an art without snobbery, which values pumpkins, pots and peasants as fully deserving of the painter's skill? Or is this an art that chooses pumpkins, pots and peasants precisely because they're things of no inherent interest, which therefore allow the artist to display and us to admire, without distraction, his extraordinary powers of depiction?

The answer is: it's both. To paint, as Velazquez does here, simply is to pay respect. He only achieves his mesmerising likenesses through intense and humble attention to what's before him. There is no skill to be admired for its own sake. Exercise of skill and regard for the subject are one. Whatever Velazquez's personal opinion of pumpkins etc might be, his art knows better. You can't dwell on his technique in this picture, without at the same time dwelling with him on the substance of the world. And that's what's so worthwhile about a likeness.

An Old Woman Cooking Eggs is certainly a showpiece picture, a theatrical array of painted things designed to attract our admiring eyes. But what it puts on display are acts of dedicated attention. The artist is like the people in his picture, holding up each thing to the light, handling it with care.

Would this answer have satisfied Pascal? He might well have replied that giving things intense attention is in itself no more worthwhile than making clever copies of them. But then nothing on earth, not even Velazquez, could satisfy Pascal.