Earnest as a YMCA secretary faced with a chronic unbeliever, Sen. Dennis DeConcini (D-Ariz.) besought Edwin Meese III to repent and change his ways.

The president's chunky, stolid choice to be the nation's No. 1 law enforcement officer obviously didn't know why he was being importuned to think of means to "restore his image."

Earlier, at the Senate Judiciary Committee hearings, Sen. Joseph R. Biden Jr. (D-Del.) had asked him how, as attorney general, he would avoid the appearance of impropriety.

Meese offered mechanical remedies. He would keep logs of telephone calls and visitors. If any question about the right thing came up, he would consult the Justice Department's legal counsel and the Office of Professional Responsibility. He will fill out financial disclosure forms.

Congress has put a high premium on contrition since the days of Watergate, and Meese's briefers obviously had given him catch phrases like "I will go overboard" and "I will bend over backwards," but he wasn't wearing sackcloth and ashes. Meese was encased in the heavy armor of the Stein Report, which absolves him of criminality, and, he insists, of ethical violations. In his Senate appearances last year, he could remember hardly anything; but he has virtually memorized the report prepared by independent counsel Jacob A. Stein. Whenever senators pressed him about exotic financial arrangements, he beat them back with the text.

Meese is not sorry, because in his mind he has nothing to be sorry about. He wouldn't even admit to the doting chairman, Strom Thurmond (R-S.C.), that he had been "careless."

It is easy to divine why President Reagan so prizes Meese. They are ideologically compatible and they share a weakness for the military and the police. Meese is imperturbable, and, with his short blond hair and his flat, unblinking gaze, he has the air of a small-town sheriff, a type congenial to Reagan. He is not unnervingly brilliant, and his nerve ends are exceptionally well-padded. Obviously, he has none of the skepticism or curiosity or imagination that can sometimes make an aide an inconvenience.

Like Reagan, Meese does not accept blame. They both live by the motto of the Order of the Garter, "Honi soit qui mal y pense." (Shame on those who think the worst.) They share a capacity for making palpably untrue claims with silencing finality. For instance, when he was being asked the traditional question about whether it is wise to name top campaign officials to head the Justice Department, Meese replied that he was exempt because "I never incurred any personal or political chits."

Republican senators spent much of Tuesday expressing outrage at the abuse Meese had suffered from people "who oppose his nomination." His detractors were accused by Sen. Alan K. Simpson (R-Wyo.) of "seeking perfection."

Sen. Orrin G. Hatch (R-Utah) fumed that Meese had been "pilloried." Sen. John P. East (R-N.C.) said Meese was a victim of "a carnivorous and cannibalistic atmosphere." Sen. Jeremiah Denton (R-Ala.) called attention to the "nobility" of Meese's character.

What Meese has most in common with Reagan is luck. In 1980, Meese was short of cash and he had fallen behind in his mortgage payments. Along comes Michael K. Deaver's friend, John McKean, who loans him $40,000 (later another $20,000) with no security and no interest payments for a year. He cannot sell his California house, and lo! here is Thomas Barrack, who finds a buyer, loans him $83,000 for the purchase and later forgives the loan and doesn't even tell Meese about it.

The Reagan transition fund gives him a check for $10,000 to cover his moving expenses from California. He is told it is illegal. He takes the money, but changes the record. Fortunately, he is owed the exact amount in "consulting fees"; and besides, Stein has since said that payment for moving expenses might not be illegal.

Later McKean and Barrack get federal jobs. But Meese persuaded Stein that there was no quid pro quo, and the frustrated Democrats fruitlessly spend their time trying to make Meese see how extraordinary his transactions were.

He couldn't see it. He said he thought that loans like his could be arranged by ordinary Americans. He apparently doesn't know that most people who default on their mortgage payments for 11 months, as he did, lose their homes.

He never questioned why people were so nice to him. That's why some do not think he should be attorney general. Lawyers are supposed to ask questions.