WASHINGTON. — Let's talk about credibility, which is this week's buzzword on Capitol Hill.
We have been watching U.S. senators decide whom to believe, Judge Clarence Thomas or his accuser, Professor Anita Hill. Ms. Hill alleged that Mr. Thomas had sexually harassed her when she worked for him at the Equal Employment Opportunity Commission. The judge said he did no such thing.
About that time, Elliott Abrams, former undersecretary of State, formally admitted that he lied to Congress at least twice about the Iran-contra scandal. The euphemism that covers his guilty plea is ''withholding information.''
A little earlier, Robert Gates' CIA nomination was before the Senate Intelligence Committee. This brilliant analyst with the steel-trap mind testified repeatedly that he didn't remember and never knew much about the Iran-contra operation that went on while he was right-hand man to its purported chief instigator.
All of this inevitably reminds of the weeks we spent watching Oliver North testify before Congress, after which he was convicted of lying and destroying government documents, among other things. He got off afterward on a technicality, which said ''totally exonerated'' him, which was another bald-faced lie.
It also brings back those lazy summer days when we watched John Poindexter, President Reagan's national-security adviser, lie to Congress, for which he also has been convicted.
Out of respect for the elderly, I will not bring up Mr. Reagan's personal professions of ignorance about what was going under his own nose. Nor will I dredge up the name of Richard Nixon.
My point is that this is a strange bunch to start suddenly talking about credibility as if it were the highest of virtues.
The Clarence Thomas drama began with President Bush's introduction of him as ''the best man for the job on the merits'' to be a justice of the Supreme Court. That set the tone for all that has followed.
Before the Senate Judiciary Committee, Mr. Thomas said he didn't really mean all the things he said and wrote when he was a lower-rung Reagan appointee striving for favorable notice by right-wingers on high. He said he had never even discussed the most controversial item on the court's likely agenda, the Roe v. Wade abortion decision. He failed to convince a majority of the committee that he had been so remote from the world around him, or that Mr. Bush had been right in describing him. His nomination was sent to the floor on a tie vote.
Then came Ms. Hill.
She said he asked her out, asked her embarrassing questions about her private life, described imaginative encounters he had seen in pornographic films, and thus made her life uncomfortable when she worked for him. He was at the time chairman of the EEOC, charged with enforcing federal rules about sexual harassment on the job.
In the great flap that erupted, the question of credibility has been asked more often about her than about him. Minority leader Bob Dole has raged on about the alleged leak of information about Ms. Hill's statement, and demanded an investigation of the leak but not the accusation itself. So has Sen. John Danforth.
I have heard no senator suggest that in judging credibility, it is useful to examine the motives of the parties involved. For example, what does Ms. Hill have to gain from lying about Mr. Thomas' conduct? What does Mr. Thomas have to gain?
So far, all Ms. Hill has gotten for coming forth is a lot of disparagement from those supporting the nomination. What Judge Thomas has to gain, of course, is a lifetime seat on the Supreme Court.
Another way to judge credibility is to look the contending parties in the eye. Most of those who saw Ms. Hill on television seem to think she was convincing. At this writing, nobody has seen Mr. Thomas comment on the matter in public. But Mr. Danforth, as his principal Senate sponsor, has presented an affidavit ''totally and unequivocally'' denying the charges.
Hmmm -- is that something like ''totally exonerated''?
If this implies that I have decided whom to believe, let me back off. What I and millions of others decided the moment we heard about these accusations was that they should be thoroughly and publicly aired before Mr. Thomas was confirmed for the high court.
Meanwhile, I suggest still another way to judge credibility: Is the party in question a political figure in the federal government?
Ernest B. Furgurson is associate editor of The Sun.