When you think about it, the term "still-life" is quite curious. What else, after all, is any painting but an image of life held still for a moment - or an eternity. So why should we be surprised if a painter of portraits decides to portray something other than people? Admittedly it may be in some ways more challenging to catch a vibrant, living human being and hold him or her still for long enough be captured like a bee in amber; a world of movement may be implied, but none of it actually there except in the painter's vision and our imagination.

David Cobley has long been recognised as a master when it comes to the particular form of still-life we normally call the portrait. The mind, indeed, boggles at the magnitude of the task involved in pinning down Ken Dodd or Alicia Markova, or Steven Berkoff, all wizards of movement, in the static form of a painting, and yet make us understand the potentiality of movement enshrined in this single, unmoving image. Compared to, say, a national treasure like Richard Briers, capturing the soul of a director's chair, or a half-drunk mug of coffee, or an untidily over stuffed wallet, must be a doddle.

But is it? The genre, after all, is called still-LIFE. There must be more to it than simply making something already still in three dimensions into something else which is in two. Almost without thinking about it, I referred to Cobley's still-lifes as capturing the "soul" of an object. That may have raised a few eyebrows. We feel sure that the Princess Royal and Sir Timothy Sainsbury have souls; likewise the Dean of Westminster and the Lord Mayor of London. But do inanimate objects share the same existential life?

Perhaps in the "real world" they do not. But in art they have to. That is the point of what an artist does. A still-life would not fulfill the "life" part of its brief unless the artist made us aware of that secret life humming within all things. The life may be lent, even in absence, by the spectre of human use; the mug of coffee is half-drunk, and it must have been half-drunk by somebody. The director's chair has recently been sat in, the wallet rifled through in search of somthing, then flung aside. Every picture tells a story, the Victorians used to say, and that is the story these pictures tell: of human life near-by, of a room just vacated.

Or at least this is the story they imply. Part of Cobley's skill lies in making us aware of a universe beyond the frame. Do his nude young women twist and turn for their own benefit, or in obedience to the unseen artist's instructions? Shelly thought that "Heard melodies are sweet, but those unheard are sweeter." Cobley thinks that seen people are fascinating, but there is a place too place in his world for those unseen, and nothing is left unaffected by their magical, mysterious passage.