TIME HEALS all wounds, of course, but it isn't always in too big a rush about it.

With last season's battle for control of the National Theatre resolved, the warring parties have turned their energies to the coming season and the care and feeding of Washington theatergoers. "I've blotted the National from my mind," says Kennedy Center chairman Roger L. Stevens, as he maps out a theater schedule with an unprecedented emphasis on new plays and center-sponsored productions.

The National's officials and their new Broadway allies, the Shubert Organization, seem equally absorbed in their own season, which includes three Broadway hits and one London sensation. A Shubert executive talks confidently of there being "enough theater to go around."

But clearly the intensity in both camps has something to do with their awareness of each other. The National is in the reputation-building business after a decade of hard times, coinciding with the Kennedy Center's rise. Stevens and his aides had box-office troubles this spring and summer, and they certainly don't want the Center to be upstaged.

Everybody connected with theater in Washington, in fact, is on his toes just now. The Folger Theatre Group is advancing on Broadway and other points north. Arena Stage, celebrating its 30th anniversary, had boldly addressed a potential identity crisis with a group of plays substantially meatier and more ambitious than the resident-theater norm. The Warner Theater and Ford's have deals in the works. Even some of the smaller companies around the city -- the New Back Alley, the New Palywrights, the Rep. Inc., the Round House, the Source, the Studio, et al. -- have big plans.

It adds up to perhaps the most varied and promising Washington theater season ever, with the reemergence of the National (once almost the only theater in town) as the major instigating factor. And in the lingering recriminations from last year's bitterness, there are important hints about the shape of the city's theater to come.

Stevens, who joined with producer and theater-owner James Nederlaner to oppose the Shubert bid to run the National, says he never objected to the presence of the Shuberts as such. He just felt his friend Nederlander "got a dirty deal" from the National's board and the Pennsylvania Avenue Development Corp. Nederlander had run the theater in the early '70s and still had his name on the lease last year when the National's board, over his objections, decided to strike a deal with the Shuberts.

There was also a money dispute between Stevens and the National, stemming from the five-year period when the Kennedy Center managed the theater as Nederlander's sublessee. The National's board contended that Stevens had illegally seized certain moneys from the theater's coffers.

Stevens wanted to argue it out in court, but wound up settling at the negotiating table this summer because "my board didn't want to get into it." Still, he says the new competition doesn't phase him. "I've never been worried about the Shuberts coming in there -- as Bernie [Jacobs, president of the Shubert Organization] would have to admit I told him when he first asked me about it," says Stevens. He finds it "rather interesting" that, despite talk of doing more minority plays and more daring plays at the National, its season is dominated by established -- and non-minority -- hits. By contrast, he says, "I'm interested mostly in new plays."

The new plays he has in mind -- all to be produced or co-produced by the Kennedy Center -- include Leslie Stevens' "A Partridge in a Pear Tree," a mystery thriller with "a million twists and turns" (as described by chairman Stevens, no relation to the author); Ruth Wolff's "Sarah in America," about Sarah Bernhardt; Robert Anderson's "Free and Clear," about a father's disappointment in his children's lack of ambition; Carol K. Mack's "A Safe Place," about an anthropoligist and his wife in the Amazon jungle, and their college-age daughter's involvement with a religious cult back home; and Bernard Sabath's "The Boys in Autumn," about Huck Finn and Tom Sawyer as adults. (Stevens has visions of "good ol' Jason" Robards and Barry Nelson as Huck and Tom; but no actors have been signed or dates set for any of these titles except "Sarah," which will star Lilli Palmer and open Jan. 26).

"I'm looking forward to the fact that we will do practically all new plays because people are writing them again," says Stevens. "Meanwhile, 'Annie' keeps going on, thank God, and enables me to do new plays that may or may not work. We figure we have still got two more years of moving those four ["Annie"] companies around."

For other plays and musicals on the Kennedy Center schedule, see "A Few Shows to Watch For" on Page G13.)

Jacobs and Shubert chairman Gerald Schoenfeld -- known in the trade as "the Shuberts" agree that the National and the Kennedy Center can thrive side by side. "I think we have the best shows," says Schoenfeld, "but we don't wish to succeed at the expense of the Kennedy Center." Jacobs adds that "Roger's hysteria -- if I may characterize it that way -- about our coming into Washington was illogical."

The National's season gets under way with a revival of the Lerner-Loewe musical "Brigadoon," opening Thursday; followed by Sidney Michaels' comedy-thriller "Tricks of the Trade," with George C. Scott and Trish Van Devere -- Oct. 7 ; and the American premiere of Peter Shaffer's "Amadeus" -- Nov. 6 .Two Neil Simon works will be follow later -- the two-character musical "They're Playing Our Song" -- late December , "I Ought to Be in Pictures," about a hack screenwriter's reunion with his daughter -- early May .

"I personally believe the National is the No. 1 theater in Washington," says Jacobs, who obviously hopes the season ahead will support that claim.

But who is "No. 1" may be less important than a few marked differences that have already emerged in the altered competitive setting. The Kennedy Center's turn toward new plays and the National's stress on somewhat known commodities is partly due to the possibility of longer runs at the National. Jacobs and Schoenfeld have already penciled in "They're Playing Our Song" for 10 to 13 weeks; and if they bring a road company of "Evita" here next summer, it could be for even longer.

"Evita couldn't play the Opera House," says Jacobs, "because 'Evita' is such an expensive show.It needs 12 to 20 weeks, unless you're dealing with a cut-down version of the show. We don't want to deal with that."

Even with straight plays, the Shuberts hope to establish 9 or 10 weeks as the norm. "I think the Washington audience is there," says Schoenfeld. "We may be pioneering, but I think we're pioneering with confidence. We're bringing outstanding material."

Higher prices are part of the gamble -- a $25 top for musicals and $22.50 for plays. "We believe a show should break even at 60 percent [attendance] and we set ticket prices accordingly," Jacobs explains. Stevens, on the other hand, talks of his determination to keep prices down. (The Kennedy Center will introduce a $25 top ticket with "Sweeney Todd" this fall; other musicals should cost less, and the top for a play will be $16.90.)

The Kennedy Center is committed to a subscription concept, giving subscribers 10 attractions a season. The National has a subscription offering for 1980-81, but only for four plays and, at that, reluctantly. "A subscription is a mixed blessing," says Schoenfeld, noting that the new Shubert Theater in Los Angeles had to drop its subscription plan so "A Chorus Line" and "Annie" could stick around for two years at a stretch. Something like that could happen in Washington, too, he suggests.

Jacobs has served the Kennedy Center as a labor negotiator, but he is harshly critical of Steven's role in running the National from 1974 to '79. "Until Nederlander and Roger Stevens became involved in the operation of the National Theatre," he says, "the National was booked 52 weeks a year.

Through their combined efforts and talents they managed to push it down to a nadir point.

"But the quarrel I really have with Roger," he says, "is that Roger should make up his mind if he wants to be in the private sector or the public sector. You can't be running the Department of Defense and also be running Hewlitt-Packard."

The danger, according to Jacobs, is that Stevens can use Kennedy Center bookings to favor shows in which he has a personal interest. Jacobs charges, for example, that another play was "bounced out" of an early slot this fall to make room for Jean Kerr's "Lunch Hour," which Stevens and partner Robert Whitehead are producing. Stevens denies it.

(And there are those -- Nederlander, for one -- who lodge similar conflict-of-interest claims against the Shuberts. The Shubert Foundation has given hundreds of thousands of dollars to the New York Shakespeare Festival, says Nederlander, and gotten such shows as "A Chorus Line" into Shubert theaters as a result.)

But for all the real confusion between the profit and nonprofit theater, the Shuberts' move into Washington seems to accent the differences.The National is luring more of the proven commercial commodities, and the Kennedy Center (while hardly thumbing its nose at a commercial musical like "Sugar Babies") is finding more new plays and forming more links with such fellow non-profit bodies as the Folger, Los Angeles's Mark Taper Forum and San Francisco's American Conservatory Theatre.

Can peaceful coexistence be in the wind?

"We've played the Kennedy Center with our shows in the past," says Jacobs, "and we will play the Kennedy Center in the future."

Stevens has been so busy optioning plays that he now has more projects than time slots. "I may have to do some plays at the National," he says.

"Wouldn't that be interesting?"