THE retiring speaker of the House, Thomas ``Tip'' O'Neill (D) of Massachusetts, has been doing the rounds in Washington like a personification of ``The Last Hurrah,'' talking affably to any interviewer with a microphone or a notebook. At the drop of a hint, or even without one, he tells how the old town has changed in 40 years. He rates the presidents he has served under - very carefully, with the tippy-toe delicacy of a big man walking on egg-shells. When he feels a need to be especially diplomatic, he starts off with his favorite preamble: ``To be perfectly truthful.... ``Tip'' is doing a little more than delivering a grand goodbye. Like anybody nearing the close of his career, he is shifting the question from, ``What have I accomplished?'' to ``What have I learned?''
It is a loaded question, splitting the vote. Those in the middle of life's journey, and later, cherish the notion that experience teaches lessons to be learned no other way. The young seriously doubt it.
An old politician like ``Tip'' knows how to satisfy both constituencies. He says he is stepping down to make room for the younger generation. But the colleagues he chooses to praise in parting just happen to be silver-haired old darlings, overflowing with the wisdom of their years.
A master of compromise like ``Tip'' will never suffer the fate of a New Zealand chief footnoted in history. When the old man suddenly disappeared, a younger fellow tribesman explained to an anthropologist: ``He gave us so much good advice we had to kill him.''
If things go according to form, ``Tip'' will merely write an autobiography, like every other public figure. The reviewers may kill the book, but no matter. The publisher's advance should make ``Tip'' rich, allowing him to live beyond the wildest dreams of any New Zealand chief. Ask Messrs. Nixon, Carter, and Kissinger and other manufacturers of the literary doorstop.
Still, while ``Tip'' is getting that memory-lane look in his eye, why not demand more from him? Must all memoirs by presidents, four-star generals, secretaries of state, and so on possess the properties of a sleeping potion?
Here are a few tips from ``Tip,'' and all other retired public servants, on how to avoid the pitfalls that await the Great Man - and us - as he looks back.
1. Delay a year before starting to write. During this time the memoirist will register the fact that he is no longer beholden to voters or party leaders. Freedom! It's surprising what that will do to put the song in a man's prose style.
2. Be brief. Most retired politicians seem to regard autobiography as a form of filibuster. Any memoir beyond 350 pages must be ruthlessly edited unless the author's name is Winston Churchill. The plea to other recollectors should be: Forget your second-grade teacher. Give us the short list, please, of people without whose help you would not have become the Great Man you are.
3. Refrain from the more obvious forms of self-justification. There is no need to verify the following: That the memoirist is against communism; that the deficit is the other party's fault; or that civil rights, in moderation, is an idea whose time has come.
4. A memoirist cannot help dropping names. But he can be expected to drop them with restraint. ``Tip'' O'Neill, for example, has told his interviewers he used to play poker with Richard Nixon. Did he also play softball with Jimmy Carter or tag football with the Kennedys? At least 10 pages should pass between such confessions.
All these little acts of self-control will leave ``Tip,'' or any future memoirist, the time and energy to tell us what we really want to learn from an insider. Just how do PAC contributions put golden handcuffs on an elected official? Has the seniority system, according to which committees select chairmen, become as obsolete as some chairmen? Does the tendency toward an imperial presidency threaten traditional checks-and-balances?
Politics - in case nobody's noticed - is going through another crisis of credibility. Politicians are hardly trusted more than the press! The public servant's memoir-as-usual - both officious and anecdotal, alternating between solemn salutes to the flag and good-old-pal slaps on the back - will do nothing to remedy the situation. Maybe the most searching memoir - St. Augustine among the ward-heelers - would count for little right now. But it might at least clear the air, arguing that if a politician could be scrupulously honest in his memoirs he could be reasonably honest in his life.
To be perfectly truthful, as ``Tip'' would say, we have arrived at a point where we need to know the worst about politics before we can believe the best about it again and fill our lungs for the next hurrah. A Wednesday and Friday column