Anyone who loves Scandinavian design -- can there be anyone who doesn't? -- will find the current exhibition at the Renwick Gallery both arresting and alarming.

Arresting because a full century's worth of examples of the Scandinavian genius for form and texture is masterfully displayed. Alarming because some of the more recent work suggests that the pure and simple "Nordic" style is tending toward decadence.

Before most American and European designers began to give even lip service to the slogan "form follows function," the leading Scandinavians were hewing to the principle that form is function. And they had low- priced, high-quality, beautiful "products for the people" in mass production.

Most of us have seen surprisingly few of the fine objects of ordinary life produced in Denmark, Finland, Iceland, Norway and Sweden, because not many of them are still reasonably priced by the time they get here. And what American furniture makers, for instance, commit in the name of "Danish modern" is enough to make a Viking cry.

Hie on over to the Renwick and see the real stuff. The arrangement is linear, from the late 19th-century Art Nouveau/Viking Revival movements through the factory- functionalism of the period between the world wars and the great flowering that followed the end of the Occupation.

Those who go on to the final section may feel they've gone a step too far, as have many of the current designers whose work is displayed there. While taste, grace and simplicity still dominate, there is a sense of diverging movements. One indulges in starkness for its own sake, which has an effect as tiresome as rococo; the other spoils a curve with a pointless recurve, or uses trick surfaces where honest textures would serve. But if it is excessive, it never reaches the sort of wretched excess -- not to mention poor craftsmanship -- that assaults shoppers seeking home furnishings in almost any American store whose prices are within an average budget.

The Scandinavian design credo can be found in the words of Poul Henningsen, quoted in the exhibition's $45 coffee-table catalogue: "Simply make things fit for use: That is enough to keep you busy, and you will sell vast quantities and make lots of money." Why can't we think like that? SCANDINAVIAN MODERN DESIGN: 1880-1980 -- Through October 10 at the Renwick Gallery, 17th and Pennsylvania NW (Farragut West station on Metro's Blue and Orange lines). Open 10 to 5:30 every day.