Ken Burns' epic PBS documentary "rethink" of the Vietnam War arrived at a useful moment last month. The historian/filmmaker has given America another "Confederate generals" quandary to ponder.

Should Dwight Eisenhower, John Foster Dulles, John Kennedy, Bobby Kennedy, Robert McNamara, Lyndon Johnson and Richard Nixon — and so many others — be forgiven for their decisions to defend South Vietnamese nationalists against Communist aggression?

Is the Vietnam War just another lost and misguided cause, like the Civil War Confederacy, to be dumped with malice into the ashcan of history?

I have never felt really at home in my country since I returned from the Vietnam War. My presence does not seem to fit in my extended family's comfort zone. My younger brother, who chose not to serve, is especially estranged from me.

This did not happen to my Dad and my uncles who fought in World War II. Their families were simply proud of them.

So you may understand why I teared up a bit watching the woman in Burns' final episode — an impassioned antiwar activist half a century ago — when she said through her own tears: "I'm sorry."

She is sorry now, not for opposing the conflict, but for despising and de-normalizing young Americans who were sent to the other side of the world to fight for their country, and for demonizing them as "baby killers."

The wounds of the past heal slowly. To whom should we turn for guidance when confronting the realities of history and deciding how to judge our forebears' errors and evils?

If anyone ever had just cause to hate Robert E. Lee and his fellow Confederate leaders, it was Abraham Lincoln. After all, Lee and the other Confederates made choices that led to the combat deaths of some 100,000 young men recruited under Lincoln's order to fight and preserve a federal union without slavery. (An additional 250,000 Union soldiers died from disease and other causes during the war.)

So what, do you suppose, would Lincoln do today about statues erected to the memory of Lee, Stonewall Jackson and other enemies of his government? Let the statutes stand or tear them down? What would he say about controversies over "Columbus Day," which arrives again on Monday?

And how would he advise us to think about other admired figures, such as Charles Lindbergh and Dr. Seuss, who should be admired no longer, some say, because of grave errors on matters of race or politics?

Actually, we know a fair bit about what Lincoln likely would do and say — because before his death he proposed a solution to the moral tensions created for all Americans by the treason and support for chattel slavery of so many of their contemporaries.

Lincoln saw full well the umbilical bond between Southern secession and slavery. In his Second Inaugural Address on March 4, 1865, Lincoln fused the Confederacy to the institution of human bondage. A desire "[t]o strengthen, perpetuate, and extend this interest [slavery]," he declared, "was the object for which the insurgents would rend the Union even by war …"

To Lincoln, every Confederate was a defender or an enabler of slavery.

But what was Lincoln's response to their treason and moral blindness? Forgiveness and pardon. Redemption over retribution. Reconciliation, so that those in the wrong could start over on a better course in life.

On Dec. 8, 1863, Lincoln had issued a blanket pardon for nearly all Confederates, saying: "I, ABRAHAM LINCOLN, President of the United States, do proclaim, declare, and make known to all persons who have, directly or by implication, participated in the existing rebellion … that a full pardon is hereby granted to them and each of them, with restoration of all rights of property, except as to slaves …"

Those pardons took effect on condition that the former rebels would swear an oath to henceforth "faithfully support, protect, and defend the Constitution of the United States and the Union of the States thereunder; and … abide by and faithfully support all proclamations of the President made during the existing rebellion having reference to slaves …"

Lincoln offered such a pardon as he found expedient for the public welfare of the United States. Once the Civil War was over, he understood, the federal government would need to reconstitute a union — not just in law, but in fact. Former rebels and slave owners needed to be reclaimed as citizens in good standing if the nation were to avoid a continuing guerrilla war in its Southern states and to ever again enjoy the moral quality of being one people.

Minnesotans have special reason to remember Lincoln's policy of giving quarter to enemy combatants. Even as the Civil War raged, he insisted on reviewing the cases of 303 Dakota Indians sentenced to death after their 1862 war along the Minnesota frontier — and spared 265 of them.

But in December 1863, even Lincoln was not yet ready to extend his pardons to the top leaders of the Confederacy. That decision he deferred.

Lincoln had earlier set forth pragmatism as his standard for decisionmaking, not narrow-minded intolerance or prejudice based on past afflictions, by affirming that "[t]he dogmas of the quiet past, are inadequate to the stormy present. The occasion is piled high with difficulty, and we must rise — with the occasion. As our case is new, so we must think anew, and act anew."

At the end of the war, Lincoln recognized that the Union again faced unprecedented problems, none greater than reconstituting one nation embracing both victors and vanquished. It was another "new case" demanding that Americans think anew and act anew.

Vengeance against Southerners would not reflect new thinking, only old antagonisms. To act anew meant replacing the arts of war with the civilities of peace.

And so Lincoln delivered to his people, North and South, in his Second Inaugural Address of March 1865, the moral grounds for forgiving former Confederates, no matter what their beliefs about slavery and the status of African-Americans.

Lincoln's moral foundation was: "Let us judge not, that we be not judged."

The New Testament quotation calls to mind the demanding standard of fairness in the teachings of Jesus — that only those without sin should cast the first stone of punitive judgment — and that, when unjustly injured by a blow to the cheek, one should "turn the other one also."

Lincoln set forth a daunting standard of mercy of his own:

"With malice toward none, with charity for all, with firmness in the right as God gives us to see the right, let us strive on to finish the work we are in, to bind up the nation's wounds, … to do all which may achieve and cherish a just and lasting peace among ourselves and with all nations."

Lincoln thus balanced "firmness" in doing what was right with showing charity for all — even for those who had not done right at all.

What's more, in that remarkable speech Lincoln argued the moral logic behind forgiving his enemies, along with all those who had profited off unjust oppression. The deaths and sufferings of the Civil War had been retribution enough, he said. The slate on which was recorded the guilt of all Americans, both North and South, had been wiped clean with human blood:

"If we … suppose that American slavery is one of those offenses which, in the providence of God, must needs come, but which, having continued through His appointed time, He now wills to remove, [then] He gives to both North and South this terrible war as the woe due to those by whom the offense came …"

Lincoln thus parried the Old Testament doctrine that an eye should always be taken for an eye in retribution — the kind of thinking that would justify the North's hounding and harassing the South forever. He pointed out that sufficient vengeance had already been accomplished through the war itself. By the end of the fighting, Lincoln argued, "all the wealth piled by the bondsman's two hundred and fifty years of unrequited toil [will have been] sunk, and … every drop of blood drawn with the lash [will have been] paid by another drawn with the sword ..."

Perhaps Lincoln, a devotee of Shakespeare (one of the three books that sat on his White House desk was a Shakespeare collection), even had in mind the climactic lines from "The Merchant of Venice": "The quality of mercy is not strained; it droppeth as the gentle rain from Heaven. … It becomes the throned monarch better than his crown."

On Oct. 2, 1865, Robert E. Lee signed the oath of allegiance as Lincoln had stipulated. But by then Lincoln was dead, and his successors did not pardon Lee or restore his citizenship as an American (it was finally restored in 1975).

In 1992, on the 500th anniversary of the arrival of Columbus in the Western Hemisphere, the late Dave Larsen, a former tribal chairman of the Lower Sioux Indian Community, and other Dakota elders organized a Wiping Away of Tears ceremony. Through this ritual, it was said, the Dakota peoples could once and for all "wipe away the tears" provoked during 500 years of contempt shown them by European immigrants to these shores, and weep no more.

I was honored to attend that ceremony and hear Dave, who died last month, voice his new spirit after the psychic burden handed down from the past was lifted through an act of forgiveness for wrongs done.

Why should not all Americans think and act as Lincoln did — think and act anew — with malice toward none and with charity for all?