IT WAS A LOVELY LATE-SUMMER NIGHT, BALMY WITHOUT BEING OPPRESSIVE, THE kind that Washington produces to welcome returning congressmen, or maybe sweeten their return for the rest of the city.

I, too, was returning to D.C., after a three-year absence, and I found myself making a familiar pilgrimage up the cream-colored steps to the Lincoln Memorial. The memorial has always seemed to me a place for orientation. And the events of the Iran-contra hearing summer, perhaps more than those of any other since 1974, had been disorienting.

I'm no expert on Abraham Lincoln, but I have always liked the memorial -- especially the Second Inaugural Address chiseled into the wall on the great man's left as the visitor comes up the stairs. On Lincoln's right side is the Gettysburg Address, which is considered so great a piece of rhetoric that generations have had to memorize it and presumably think about it. But to me, the Second Inaugural had always seemed much more interesting. Why, I didn't exactly know. The satisfaction I took from it seemed mostly unconscious -- an unexamined pleasure. How unexamined I realized last August as I stared, perplexed, at a passage in its third paragraph.

Mostly, the Second Inaugural is a healing speech, looking forward to the end of the Civil War, which turned out to be only 36 days away. Lincoln talks first of the "progress of our arms," which he trusts is "encouraging to all." The inaugural's middle section makes several important concessions to the battered South: that neither side had started out seeking war; that each at least thought it was in the right; and that responsibility for slavery was not necessarily a southern monopoly. That sets up the grand conciliation of the famous final paragraph: "With malice toward none, with charity for all . . . let us . . . bind up the nation's wounds . . ."

But this summary neglects a 13-line passage -- the chunk I found myself gawking at last August. A chunk that suddenly looked as appropriate, to cite Raymond Chandler, as a tarantula on a slice of angel food.

About halfway through the oration, long after Lincoln's hopeful hint about the war's outcome, he brings the issue up again, and in a much bleaker key. "Fondly do we hope -- " the passage begins, "fervently do we pray -- that this mighty scourge of war may speedily pass away." Okay so far; it even rhymes. But it goes on: "Yet, if God wills that it continue until all the wealth piled by the bondsman's {slave's} two hundred and fifty years of unrequited toil shall be sunk, and until every drop of blood drawn with the lash shall be paid by another drawn with the sword, as was said three thousand years ago, so still it must be said 'the judgments of the Lord are true and righteous altogether.' "

Howzat? The passage -- melancholy, almost mystic -- seems to run exactly counter to what had preceded it. Here is Lincoln seized by a dark fantasy, an intimation of Hell; a war that, far from ending in a month, will go on for centuries.

The vision is fatalistic. It suggests that a people's destiny does not necessarily rest in its own hands. All the resources the Union had brought to bear, the blood and money and firepower and generals -- Lincoln seems to be entertaining the grim prospect that they mean nothing. In the context of the rest of the speech, this seems perverse. Given the promise of the Gettysburg Address, it seems cruelly contrary: Maybe the dead at Gettysburg had indeed died in vain. In fact, alongside any political speech one might recall, it seems downright odd.

"To my knowledge, it's absolutely unique," says David Herbert Donald, Charles Warren professor of history at Harvard and author of a standard text, Lincoln Reconsidered. "I don't know of any other president who's used the inaugural occasion to express the idea that fate is beyond the decision of individuals to control. I have a curious sense nobody thought about what he said. If they had, they would have been absolutely horrified."

Of course, I have since learned, there is a lot we now know about Lincoln that probably would have startled, if not horrified, his constituents, and the passage is consistent with some of his least accessible personality traits. His swings of mood are well-documented. According to Roger Brown, professor of history at American University, "He waged a lifelong struggle against his own black despair and feelings of inadequacy, and that somehow fostered a sense of being in the grip of larger forces." His favorite line from the classics, says Donald, was Hamlet's remark: "There's a divinity that shapes our ends, Rough-hew them how we will." In less oppressed moments, Lincoln dubbed this personal sense of determinism the Doctrine of Necessity; "the human mind," he once wrote, "is impelled to action, or held in rest by some power, over which the mind itself has no control."

But to describe the passage as a product of Lincoln's personal turmoil, or even of a deeply held philosophy, did not help explain its effect on me, or my growing suspicion that rather than weakening the speech, the passage made it. Fred Antczak, professor of rhetoric at the University of Iowa, without discounting a personal element, thinks the dark digression also had a political motivation. The language of the entire speech is heavily biblical, he points out. Lincoln realized, consciously or intuitively, that a reverence for the good book's rhetoric was one of the few areas of linguistic agreement between a South and a North that could not even concur on the name of their war. It was only on such common language that peace could be built.

And the rogue passage, Antczak ventures, was an attempt to exploit an even more specific literary tradition. There is an ongoing argument in American letters about free will, he says. On the one hand is the Emersonian, transcendentalist line that says a man can achieve anything if only he tries hard enough. Opposed is an older tradition, traceable to the Puritans via Melville, suggesting that man's actions are circumscribed by God's will (Ahab will not get that whale, no matter how much he wants it) -- and, moreover, that those limited actions are subject to divine judgment (Ahab was not only foolish, but wrong to endanger his crew's lives).

The Emersonian tack was no help to Lincoln. Both South and North had tried hard, but only one would achieve its ends. Moreover, stressing Emerson's "can-do" philosophy might only stimulate the North to do what it would soon be able to: roll over the South like a bulldozer. Instead, says Antczak, Lincoln turned to the Melvillean tradition of limits and moral introspection. By putting North and South abjectly together before a 19th-century version of the Puritan "angry God," Lincoln made them equals, rather than conquerer and conquered. And he was stage-whispering to the North, "Even though victory seems close at hand, there is still a force, a moral force, in the universe, that could turn it upside down. Be humble."

"It's a strange passage from a straight-thinking American farm boy from Illinois," admits Antczak. "You could imagine it a lot quicker in Dostoevsky or the Book of Job."

And certainly not out of the mouths of today's politicians. John F. Kennedy's answer to Lincoln is inscribed on his own monument in Arlington. "Let us go forth to lead the land we love," he said, "asking His blessing and His help, but knowing that here on Earth God's works must truly be our own."

And by the early '80s, God had exited the scene altogether, says Kenneth Khachigian, a political consultant who wrote speeches for Ronald Reagan early in his presidency. God's moral force was apparently incompatible with the decade's entrepreneurial ethos. "The country's not in the mood to be told that life is out of its hands," says Khachigian. "We Americans have come to feel that we're in charge of our own destiny, which is the ultimate result of our personal liberties and freedoms." That is, if Big Government would just get off our backs, no force on (or off) Earth could stop us. Is there no place, then, for the suspicion that we may not have final cut on our national mini-series? Oh, sure, said Khachigian. "We go to church on Sunday and follow our own religious beliefs, a lot of which obviously state that God's will will be done regardless of what mere mortals do. But the sheer politics of it is, woe betide the guy who gives you Jimmy Carter stuff."

Ah, Jimmy Carter. Khachigian has indeed put his finger on the recent president who seems best to reflect the spirit of my Lincoln passage. According to Hendrik Hertzberg, who used to write his speeches, Carter's version of the Hamlet quote was a little sign on his desk that read something like "O God, Thy sea is so great and my boat so small . . ." If he didn't exactly buy into the Doctrine of Necessity, Hertzberg says, Carter "certainly did talk frequently about the idea that the United States cannot determine everything and there are things beyond our control." Unfortunately for Carter, American voters, hearing that belief and other "negative" sentiments expressed in orations like his 1979 "malaise" speech, decided that the lack of control was his, not theirs. "They believed he had been overcome by the problems," says Hertzberg, "and the unfortunate result is that now only mindless optimism is permitted."

I myself am beating a quick retreat to the past and those words on the creamy marble. In addition to presenting a startlingly powerful image, they offer a terrific illustration of humility on the part of the powerful -- a characteristic I consider essential in America, and underpracticed. One of the reasons that Lincoln's expression of fatalism got chiseled in stone, while Carter's darker rhetoric helped sink his little boat, is that the Second Inaugural came at a moment when Lincoln was engaged in perhaps the biggest act of Emersonian self-determination the nation had seen since its revolution. The Civil War was Lincoln's war, as much as any of our wars has belonged to a president; he had seen it through some horrendous times, and he was now on the verge of a victory. From the height of that triumph, from the midst of what some men might take as proof that God was on their side, Lincoln was able to remember, and state in starkest terms, that there is a higher morality than victory, and there are limits that must make us humble even in our triumph.

I am not a religious person. I don't think we must always, as Lincoln did in the Second Inaugural, rely on the image of a God to remind us of the humility that should accompany strength. But reflecting on the arrogance of the Bill Caseys and the fanatic presumptuousness of the Ollie Norths -- their willingness to set America's awesome forces into action with a minimum of reflection or even consultation -- I realize why I climbed those steps last August. I am thankful to Lincoln; thankful to him for having tossed into the American rhetorical tradition a strong dash of humility to balance out our overwhelming intoxication with our own power. I know he saved the Union. I know he freed the slaves. But it is for those 13 lines in the Second Inaugural Address that I'm going to celebrate his birthday tomorrow. ::