SHOULD THERE BE a Richard Milhous Nixon Presidential Library? And should it be located at Duke University, which has been discussing the idea with Mr. Nixon? He and Jimmy Carter are the last ex-presidents entitled to consider their papers "private property," though a 1974 Watergate-related measure regulates strictly the conditions of access to the Nixon papers and tapes.

For his part, Mr. Carter has been completing arrangements on constructing a presidential library in Atlanta. But future chief executives--including Mr. Reagan--must administer their records under the constraints of the Presidential Records Act of 1978, which took effect last January. Since Mr. Carter's library undoubtedly will operate under the ground rules governing public access to presidential records --and the limits on such access--provided by the 1978 statute, only Richard Nixon's papers remain suspended in administrative limbo.

Is that a good idea? Should they remain as they are, with records of the presidential years at two Washington-area locations and Mr. Nixon's pre- presidential files in California, both tightly regulated by the National Archives? For a number of Americans, such administrative limbo may seem preferable to the alternative--allowing the only president in American history who resigned in disgrace to achieve, belatedly, the memorial honors be stowed by every presidential library on its central figure. Inevitably, in providing a home for both memorabilia of Mr. Nixon's White House years as well as for his public papers--a practice followed at all seven existing libraries--such a Nixon "museum" would serve a commemorative function. (More than 1.6 million Americans visited the presidential museum/libraries last year.)

Mr. Nixon aside, the presidential library system has improved significantly researchers' access to, and awareness of, recent historical materials. In the past, presidential records all too often were ill-tended: some lost, others destroyed, and many more simply unavailable. Last year, by contrast, almost 7,000 researchers used the extraordinary resources -- including 119 million documentary pages--of the seven presidential libraries, all at an acceptable cost of $6.25 million for staff and programs.

As for Mr. Nixon's prospective library, might it not be better--sins of the past notwithstanding--to collect his files in one place for easier and more sustained scrutiny by researchers? Housing them at an outstanding university such as Duke, moreover, offers a guarantee of the integrity of the stewardship. Far better Durham, N.C., than San Clemente or a similar outpost of Mr. Nixon's Elba period.

Several conditions must be met, of course, before Duke could proceed. For one thing, Congress would have to revise the 1974 statute to allow Mr. Nixon's presidential papers and tapes to reside outside Washington, though under the same strict archival control. In addition, Mr. Nixon probably would be required to drop his remaining lawsuits against the government that deal with the papers and tapes--or settle them--before Congress approved any library anywhere. The provisions for the management of the library also would receive close attention from both Congress and the public. These conditions met, it makes sense to ensure and regularize access to the Nixon materials in some sort of presidential library, albeit one with a "museum" aspect. They are not only his papers, after all, but the country's--and it is not only his history, but the country's.