Going to the Comedie Francaise and not seeing a Moliere play is like traveling to Paris and avoiding (pick one: the Louvre, April or your candidate for Greatest Restaurant in the World).

If you get to go often, you may brag about skipping the obvious. Otherwise, it's a crime to come so close but miss one of the world's great experiences.

A Moliere standard, "The Misanthrope," will be peformed by the Comedie Francaise at the Kennedy Center next weekend. However, to fit into Washington's festival of French culture of the 1820s to 1850s, "Paris: The Romantic Epic," the company is doing Victor Hugo's 1838 play, "Ruy Blas," this week. It is an interesting period piece by the great writer of novels for American intermediate college French class, but not the high art for which the Comedie Francaise is known.

This makes it a good choice only for those who already know the company's Moliere repertory thoroughly - and that consists of 32 plays, most of which have been more or less steadily in production since the 1680s - or who have tickets for next weekend. It would have been even better to have a lessknown Moliere play here, rather than the Hugo or the 1907 comedy, Feydeau's "A Flea in Her Ear," that will run next Tuesday through Thursday. And even then, one regrets that, for reasons of cultural symmetry at the Kennedy Center, this rare visit did not give us the chance to see the company do Racine or Corneille. The fact is simply that it is easier to find fine music and dance of the romantic period than theater.

In "Ruy Blas," the politics, as well as the theatrical conventions, must be viewed indulgently by a modern audience. It is not the fact of age that dates the play - Moliere's rapier wit cuts easily through the centuries - but that it was written as idealistic propaganda. Attempts to delineate human character generally wear better on the stage than philosophical proclamations.

The title character in "Ruy Blas" is a valet at the court of Carlos II of Spain, who proves that the common man is more noble than the nobility. There are some stirring speeches about the good of the country, but this superiority is chiefly evidenced by the valet's knowing better than the king how to revere Perfect Blonde Royal Womanhood.

The political context is, of course, 19th-century France and not 17th-century Spain, where, in fact, that king's failure to impregnate that queen resulted in the Spanish throne's going to the French Bourbons. But it is an uninspiring form of radicalism to claim for the common man merely an ability to fit into the old courtly roles, which great earlier writers, in Spain as well as France, had long ago ridiculed.

Nevertheless, the Comedie Francaise plunges valiantly into this antique with such verve and dash as to salvage much of what must have been its original emotionality. The possibilities for irony are under such tight control in the hands of these skilled actors that the play is saved from being camp. Its finest moments are the few bits of intended comedy, but its exaggerated tragedy does not become ludicrous.

A particular pleasure of the production is the costuming, which suggests Velasquez in motion. But unlike the Moliere productions, the play does not allow the perfect blend of voice and action that makes the experience rich even to those whose French is sketchy. Simultaneous translation is available for all the plays through rented earphones, and, with all its annoyances, is still probably a good idea for any but the fluent who plan to see "Ruy Blas." For the Moliere plays, one would be better advised to read the full play first, and then simply enjoy the rich interplay of voices as one would at an opera. CAPTION: Picture, GENEVIEVE CASILE AND FRANCOISE BEAULIEU IN VICTOR HUGO'S "RUY BLAS."