"Lavender Mist," the 1950 canvas by the late Jackson Pollock - for which the National Gallery of Art last October paid about $2 million - was so costly for a reason. That dripped and sprinkled Pollock is an icon of our time.

All revered painting represents. The Gallery's new Pollock - which will not go on view there until the new East Building opens to the public in 1978 - is a picture of something. Its subject is the field. What we value when we see it is the way it represents something that we know.

The field Pollock shoes us is inclusive, not exclusive, open and continuous, nonhierarchical, non-static. Like other fields painted by other field painters - Barnett Newman or Mark Rothko, Kenneth Noland, Richard Estes, the list goes on and on - it may be read at once even as it leads the eye through energized and beautiful always-changing sameness.

As the sculptors of old Greece carved men that seemed as gods, as the painters of the Renaissance all portrayed perspective's measurable space, most abstract painters nowadays, in one way or another, use the field as a theme. The field may be seen in the open whiteness between Morris Louis's rivulets of color, in the grids of Agnes Martin, Sol LeWitt, Carl Andre, in the all-over polish of the photo realists, in Jules Olitski's atmospheres, in the striped paintings of Gene Davis. Painted fields replicate because they condense truth. In the image of the field we see the way that modern man perceives, survives and thinks.

Artists now, as always, paint what should be seen. Our lives are so complex, we must metally adjust to so many different worlds, it is not surprising that when artists show us beauty they give it field form.

Art historians tend to tie the drip paintings of Pollock to Cubist fracture, flatness and to the New York School, but the fields that he painted reflect much more than art. Think of television ads, the jazz of Charlie parker, pro football, eight-lane highways, the popularity of dope - one can see in Pollock the new conventions, the new speeds and even the new pleasures of the age in which we live.

You drive to work, you carpool. You half-hear the radio, the music, news and ads, even as you converse with those who sit beside you. You read the road, the road signs and the rear-view mirror. Prior to our century, no human in your gene-line ever moved so fast, or ever learned to process such quickly shifting information, and yet you hardly notice. Is not Pollock's field, with its never-ending, always-changing, interwined continuum, a portrait of the shifting patterns of your thought?

Baseball is a linear game. The pitcher throws, the ball moves toward the plate, the batter starts his swing, the play evolves in sequence. Pro football is a field game. The offensive team confers, while the defense waits. For a moment nothing happens, but when the ball is snapped, 22 strong men explode into movement. The only way to see it all, the pass patterns, the blocking, the handling of the ball, the rotation of the zone, is to see it all at once. Those who perceive football, and they number in the millions, have learned to see a field, not just component parts. If one had to paint that moment of pure action, and the moments that perceded it, and those yet to come, would not the diagram produced look much like a pollock?

Pollock painted movement, acceleration, speed. The modern eye that scans Pollock's energized continuum has been atuned to quickness by a thousand other visions, by the views from airplane windows, by movies and TV. The slowness of old movies we recognize at once. We see the slow detective slowly comprehend a clue, we see his cold eyes narrow as the truth sinks in - then, cut - we see the clue itself. It lingers on th screen. New films are much faster, as are those TV ads that tell half a dozen stories in less than half a minute. TV is continuous, repetitors, regular. Television ads replace one another as regularly as rock beats or the baskets scored in basketball. One ad, one beat, one basket or one square foot of painted field is as important as another.

o read a Pollock painting, to trace those swelling lines, over, under, in and out, is to set one's mind adrift. Marijuana is now smoked, for fun, by millions in the Western world whose parents would have hated the experience of the high. Charlie Parker, at first hearing, seemed to dissolve melody, as a Pollock, at first glmpse, seemed to dissolve space, as dope or meditation seems to somehow liquify the sequences of logic, but that undirected drifting, that moving with the flow, does not scare as it might have 30 years ago. Immersion in fluidity is a modern mental pleasure.

Pollock, it is true, did not invent the field. He learned much from the past. Years before he made the paintings we revere, other artists, writers, scientists and seers had sensed the truth he seized. Einstein knew the field, so did Joyce and Eliot, but Pollock made it visible. There are other reasons for his fame, a legend hovers round his suffering, his siolent death, but his early, passionate and beautiful portraits of the field guarantee his fame.

"Millions of artists create," wrote Marcel Duchamp, "only a few thousand are discussed or accepted by the spectator and many less again are consecrated by posterity. In the last analysis, the artist may shout from all the rooftops that he is a genius; he will have to wait for the verdict of the spectator . . .All in all, the creative act is not performed by the artist alone; the spectator brings the work in contact with the external world by deciphering and interpreting its inner qualifications and thus adds his contribution to the creative act."

Jackson Pollock's best works cost $2 million now - they are the most expensive pictures ever made by an American - because we recognize within them something all of us have seen.