AS HE WORKED ON HIS forthcoming inaugural address in late 1976, Jimmy Carter examined all the earlier ones and fastened, typically, on Woodrow Wilson's. Perhaps, though he doesn't say so, it was significant that Wilson had also been Southern-born and a man of religious faith.

"Like him," Carter writes, "I felt that I was taking office at a time when Americans desired a return to first principles. . . . His call for national repentance also seemed appropriate, although I feared that a modern audience might not understand a similar call from me."

The passage is revealing. Carter sounded no call for national repentance as such on January 20, 1977. But then and thereafter, through his four years in the White House, Americans never quite escaped the suspicion that he was preaching at them -- though usually, to be sure, from behind a protective grin. The need for sackcloth and ashes was always somewhere in the picture.

Readers of Keeping Faith are apt to experience the feeling again. Not that it is an obnoxiously pious or self- righteous book. But there is in it the same familiar tone of painful earnestness and moral assurance, bordering at times on the homiletic. Moreover, the austerity of Carter's precise prose leaves few channels for the richer juices of life to run. Of one thing, however, and that not insignificant in our time, we may be sure. This is Jimmy Carter's authentic voice. No ghostwriter has haunted this house.

The publication of a presidential memoir, so soon after the author's exit, is of course an American political Event, automatically. Carter's memoirs will be scrutinized more eagerly than most for clues to the lingering puzzles about him, and about his hurried appearance on the Washington stage.

He was certainly different, a card-carrying Christian and a Deep Southerner, from a family of eccentrics. But what was he like? What were his purposes? What kinds of success did he enjoy, or failures suffer, in his own eyes?

Unfortunately, the personality reflected in these pages is a bit blurred. It will disappoint those who assume that every public man floats, like an iceberg, on a hidden substructure of self-contradiction. The Jimmy Carter appearing here is the same sober, energetic, earnest Carter who stood before us for four years -- friendly to a point, but with the icy eyes and the grin not quite congruent; not exactly humorless but not witty either; unschooled in and to some extent skeptical of Washington's accustomed rituals; a president who assumes, sometimes wrongly, that others take public duties as seriously as he does, and therefore act from the same disinterested and rational motives.

Sobriety and public-spiritedness are the keynotes -- hard work, studious attention to detail, for instance. (Carter tells us that along with his maps and briefing books, he carried with him to Camp David for the famous meeting with Begin and Sadat "my annotated Bible which . . . would be needed in my discussions with Prime Minister Begin." Later, he tells us that when the cascade of White House paperwork threatened to overwhelm him he arranged to take a speed-reading course, and quadrupled his speed. No mini-memos for him!)

Carter also appears as a man to whom the revealed truths of evangelical religion are of hourly importance. He "prayed a lot"; he urged Premier Deng Xiaoping to allow freedom of worship and the distribution of Bibles in China. Learning of his wife's despondency at a hard moment in 1980 he reminded her of the New Testament verses they had read (in Spanish) the evening before: "Let not your heart be troubled. . . ."

But in many ways, the most personally revealing aspect of Keeping Faith is the conventionality of its thumbnail portraits. There are neither saints nor rogues in Carter's gallery, and lots of studies in shades of gray. If he likes gossip you'd never suspect it. Even the rascals of the family, Miss Lillian and Brother Billy, seem a bit bland, although he reveals that Miss Lillian once jocularly addressed the King of Morocco, as a "damn foreigner." Billy, for his part, "exercised bad judgment" and had a "drinking problem" which he faced "courageously."

There is nothing personal here about Hamilton Jordan and Jody Powell. Zbigniew Brzezinski is, next to his family, "my preferred seatmate on a long trip . . . we might argue (about what, Carter doesn't say), but I would never be bored." Warren Christopher is "the best public servant I ever knew"; Helmut Schmidt is excitable, Deng "tough," Sadat and Ohira of Japan "special friends" among foreign statesmen.

What one misses, except in the case of John Anderson, the spoiler, and William Sullivan, the insubordinate ambassador in Iran, both of whom get trips to the woodshed, is an occasional splash of vinegar. Not even Ted Kennedy is roughly handled. Generally, Carter seems to view others, however vexing they may be, as mirrors of his own guileless character, errant sometimes but not malicious. If there is what Jungians would call a shadow side of Carter, it is well suppressed.

Carter's presidential purposes, measured by the space he gives them, are equally unsurprising. Often for reasons not of his choosing, Carter became overwhelmingly a foreign-policy president. The pages assigned to distant imbroglios -- Mideastern negotiations through Camp David (substantially more than a fourth of the book), the negotiation of SALT II and the ratification of the Panama Canal treaty, the Iranian revolution and the hostage crisis -- all but overhwelm the agenda.

Accordingly, the domestic scene is scanted. There is a short chapter on the Bert Lance affair, interpreted as a press escapade, in which Carter skirts the issues that absorbed the U.S. comptroller general in two large volumes and the Senate Government Operations Committee for weeks. There are sporadic, often cursory, discussions of energy, budget policy, health planning, the Kennedy political challenge. There is a running motif of sidelong and baleful comment on the (usually unsatisfactory) performance of the press.

The latter, incidentally, will be of interest in media- haunted Washington. Keeping Faith suggests that Carter, maybe wisely, paid as little attention to press notices as any president ever has -- his must be the first presidential book in decades that omits even Scotty Reston and Walter Cronkite from the index. But some of Carter's suppositions -- e.g., that former senator Frank Church, source of an untimely leak about the Soviet brigade in Cuba, was "a favorite of the Washington press" -- are ludicrous. Others -- e.g., that the Kennedy forces' transparently phony plan for an "open" convention in 1980 was generally approved by the press--are simply misinformed.

The thin coverage of domestic matters means that such highly-advertised Carter causes as deregulation, price stability and the long-forgotten "zero-based budgeting" are all but ignored, perhaps for the natural reason that many such hopes were disappointed. Still, a president's frustrations can be instructive, and Carter's, at least in home politics, are muted. For example, he makes his relationship with the congressional leadership sound considerably more cordial than it was reputed to be.

For a variety of reasons, the account of what Carter clearly sees as the signal success of his presidency -- the Camp David accords -- is the liveliest, as it is the longest, of the book. Camp David showed Carter at the top of his form: patient, well-briefed, resourceful, meticulous, willing to wager presidential prestige on thin hopes and prevail, and compassionately attentive to the foibles and sticking points of his prickly negotiating partners, Begin and Sadat.

From extensive personal notes, Carter reconstructs an absorbing account of the roller-coaster search for agreement in the Maryland hills. He recounts how he refereed, in a small study at Laurel Lodge, two lengthy and acrimonious arguments between Sadat and Begin; how their passionate altercation was oddly punctuated by occasional bursts of laughter, as when "during an argument about which one of them was responsible for the hashish trade through the Sinai." Carter himself drafted or vetted every line of the final texts of the Camp David accords.

Winston Churchill once called Neville Chamberlain "a good lord mayor of Birmingham in a lean year." On the strength of the Camp David narrative alone, Carter must be pronounced at least a superb secretary of state in a good year.

Was he more? Or perhaps less? That was the question that lingered when Jimmy Carter left Washington, shadowed by a stinging repudiation at the polls. The repudiation shocked him. Carter characteristically believed that when American voters compared his careful, rational and moderate positions with what he viewed as Ronald Reagan's rash hip-shooting, their verdict would be foreordained. But Crisis, the recent (and more vivid) memoir of Hamilton Jordan, is far more revealing about the political adversities of 1980. Jordan, among other things, grasps perversity and paradox more readily than his chief.

In Washington, through which Carter passed almost as a stranger, a feeling persists that some critical "presidential" trait was lacking in the unusual Georgian from Plains. Part of this is undoubtedly Washington vanity, sharpened in Carter's case by his having snatched the presidency from under the noses of its gatekeepers.

Neither the question of Carter's capacity, nor the ultimate significance of his presidency, can be settled now. American presidencies do not lend themselves to short-range assessment. The final verdict depends on time and events still to come, including the performance of successors and the durability of the issues he thought important. Certainly Carter's presidency cannot be measured, though it will not be diminished, by this rather curious book.

With the exceptions of the Camp David account, and a few unintended glimpses of self-disclosure, Keeping Faith is the work of a worthy. It reads at times like a prospectus for a presidency, not a retrospective upon one.

But while it is neither intimate or consistently revealing, Carter's memoir does correct some misconceptions. Carter is convincingly shown to have suffered, within his divided party, for recognizing candidly that "sense of limits" of which he spoke on inauguration day: limits on American power abroad, limits on our ability to sustain a cornucopia of entitlements without bankruptcy. Already, Carter's presidency seems an interval, a pause, between the disintegrating hopes of the 1950s and 1960s and the stark reaction that came with Reagan.

As president, Carter suffered from an inability to dramatize and project himself or his goals. He was as short of theatrical talents as his successor is long on them. These memoirs suffer from the same defect. He was an intelligent, morally serious man of high purposes, almost, as said, a Victorian worthy. But he lacked the epic sense and the streak of naughtiness that may be essential to great public men. Keeping Faith is as wholesome as milk, unlaced by the acids that amuse or startle. Sober, responsible, truthful, intelligent, earnest, rational, purposeful. Thus the man: thus the book.