WASHINGTON — The other three living former American Presidents — Jimmy Carter, George H.W. Bush and Bill Clinton — are all scheduled to show up tomorrow (Thursday) at the dedication of the George W. Bush Presidential Library at Southern Methodist University in Dallas. It will be another of those mandatory gatherings at which genuine sentiments and observations will be suppressed or set aside for the sake of the appearance of national comity.

It will take place as the public debate continues as to whether the man conveniently if unkindly referred to as Duyba was the worst of all American presidents, just one of the worst, or not as bad as he is generally said to have been. That broad blanket seems to cover the consensus of many academic scholars who have looked back at his disastrous misadventure in Iraq, his failure to end the wars there and in Afghanistan, his botching of the economy and of the national response to Hurricane Katrina and other shortcomings.

One dissenting voice has come from a professor at the U.S. Naval College named Stephen F. Knott, who has written that the junior Bush has been a victim of a “rush to judgment” by prominent historians and scholars including Sean Wilentz, Eric Foner, Robert Dallek and Douglas Brinkley. These and others, Knott has suggested, have “revealed partisan bias and abandoned any pretense of objectivity” in their gallop to condemn the Dubya presidency.

It’s an axiom of scholarship, and of writing history in particularly, that wisdom and prudence require the passage of a decent period of time to assess properly the ramifications of the decisions and actions of public figures. But in the 12-plus years since the junior Bush took office, and the decade since he launched his war of choice in Iraq, which set American foreign policy of multilateral engagement on its head, there has been time enough to render the judgment.

The wreckage of that policy, and of Bush’s neglect of the domestic economy as well, have been sufficiently clear, occupying the bulk of his White House’s successor’s time and energies to right the leaking ship. They have emphatically made the case that the George W. Bush who will be honored at his library’s dedication was no Lincoln, FDR or even Jimmy Carter, who at least sustained little lasting damage in his four unheralded years as president.

Nevertheless, Carter and Clinton, along with loving father George H.W., will offer the usual gentle salutes to the office they once held in tribute to the honoree. President Obama showed the way when Dubya’s official White House portrait was unveiled last year. He said diplomatically that “we may have our differences politically, but the presidency transcends the differences. … We all love this country; we all want America to succeed.”

Such occasions call for checking partisanship and candor at the door in favor of mealy-mouthed pap. One cannot but recall Bill Clinton’s observation at the funeral of Richard Nixon, apparently with Nixon’s resignation over the Watergate cover-up in mind, that a man should not be judged by a single event but by his entire public life. One could also say to that, in Nixon’s case especially: Amen.

In this forthcoming gathering, one is also reminded of the comment of Senate Republican stalwart Bob Dole when President Ronald Reagan sent three former presidents — Jimmy Carter, Gerald Ford and Nixon — to represent him at the state funeral of assassinated President Anwar Sadat of Egypt in 1981. The trio reminded him, the famously acid-tongued Dole said in the jocular setting of a Gridiron Dinner, of the three monkey of the famous statue: “See No Evil, Hear No Evil, and — Evil.”

Time, however, often softens harsh judgments and personal relations. Clinton and the senior Bush, the man Clinton ousted from the Oval Office, became constructive partners later in tsunami relief and other humanitarian causes. So look only for at least sympathetic understanding tomorrow from Dubya’s predecessors at his library dedication.

(Jules Witcover’s latest book is Joe Biden: A Life of Trial and Redemption” (William Morrow). You can respond to this column at [email protected].)