Undated (AP) _ Here are brief biographies of four American Roman Catholic bishops who addressed Pope John Paul II on Wednesday during his meeting with the bishops in Los Angeles:

--- Cardinal Joseph L. Bernardin of Chicago

Cardinal Joseph L. Bernardin's talent for conciliation has brought new hope to his once-troubled archdiocese and won him a reputation as a peacemaker in the U.S. church.

National religious leaders also say he has established himself with the Vatican as a healer of rifts and defuser of crises in conflicts between Rome and more liberal elements in the American church.

''My basic responsibility is to preach the Gospel, and this I try to do,'' says the 60-year-old leader of the 2.5 million-member Chicago archdiocese.

He succeeded the autocratic Cardinal John P. Cody, who, before he died in 1982, had been accused of misusing up to $1 million in church funds to benefit a relative.

Bernardin is ''a mediator, sometimes to the point where he even exasperates his friends,'' says the Rev. Richard T. McBrien, head of the theology department at the University of Notre Dame. ''The Vatican knows that, and when they mess things up, they always call on Bernardin to patch things up.''

Bernardin's greatest achievement as a fence mender came in May, when he helped persuade Rome to restore the authority stripped from Seattle Archbishop Raymond G. Hunthausen because of his unorthodox approach to some church matters.

During his term as president and general secretary of the National Conference of Catholic Bishops, Bernardin helped develop a consensus on the bishops' controversial 1983 pastoral letter on nuclear war.

Bernardin was born in Columbia, S.C., where he was ordained in 1952. In 1966, he became auxiliary bishop of Atlanta. Six years later, he became the nation's youngest archbishop when he was installed in Cinncinnati.

--- Archbishop John R. Quinn of San Francisco

Archbishop John R. Quinn of San Francisco has a reputation for giving voice to unpopular thoughts, in his city and in the Vatican.

At a synod in Rome in 1980, Quinn told other bishops that more than 70 percent of American Catholic women ignored the church's ban on contraception, and that a majority of their priests supported them.

Quinn, however, has supported Rome on that issue, and also has vigorously supported the church's prohibitions on abortion, homosexual activity and ordination of women.

''I am a Catholic bishop. I believe what the church teaches and I stand by it with all my heart,'' he says.

As archbishop of San Francisco, he has named a full-time AIDS chaplain, provided a convent for an AIDS hospice, led annual prayer services for AIDS, condemned discrimination against AIDS patients and spoken against the notion that AIDS is God's vengeance on homosexuals.

He has called for a nuclear arms freeze and has opposed U.S. economic aid to the Nicarguan Contras.

He dismisses labels of ''liberal'' and ''conservative'' as meaningless.

''Someone said a conservative is someone who has to have reasons before he changes his mind,'' he says. ''I like to think that's the way I am.''

Quinn was born March 28, 1929, in Riverside, Calif., and ordained in 1953. He was appointed auxiliary bishop of San Diego in 1967, bishop of Tulsa and Oklahoma City in 1971, the first archbishop of Oklahoma City in 1972 and archbishop of San Francisco in 1977.

--- Archbishop Rembert G. Weakland of Milwaukee

Milwaukee Archbishop Rembert G. Weakland, who headed a committee that drafted the American bishops' controversial pastoral letter on the U.S. economy, acknowledges that he is considered a liberal.

That, he says, is why he came in third in last year's election for president of the National Conference of Catholic Bishops.

Weakland, 60, who began religious life as a Benedictine monk and once was a college music teacher, testified before Congress last December on the pastoral letter titled ''Economic Justice for All.''

''Employment is a basic right, a right which protects the freedom of all to participate in the economic life of society,'' he told the Joint Economic Committee. ''Full employment, therefore, is the very foundation of a just economy.''

The pastoral letter, adopted by the bishops conference on a 225-9 vote in November, 1986, described poverty in the United States as a moral scandal and called for radical changes affecting all levels of society.

Weakland has served as archbishop of the 662,000-Catholic Milwaukee archdiocese since 1977. Before that he was Abbott Primate of the Benedictine order.

A native of Patton, Pa., Weakland entered the Benedictines in 1945 and was ordained in 1951. He studied music in Italy, France, Germany and the United States and taught music from 1957 until 1963 at St. Vincent College in Latrobe, Pa.

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Archbishop Daniel E. Pilarczyk of Cincinnati:

Archbishop Daniel E. Pilarczyk succeeded Joseph Bernardin in 1982 as head of the 550,000-member Cincinnati archdiocese.

Pilarczyk, a theological moderate, describes his archdiocese as deliberately progressive.

''But you have to give both of those terms their proper weight,'' he says. ''Deliberately in the sense that the Catholic people in the archdiocese of Cincinnati are not the type of people who are going to run crazily after every new thing in the church.

''At the same time, they are the kind of people who say, if this is the direction in which the church is generally going, that's the direction in which we should be going,'' he says.

Pilarczyk, 52, a native of Dayton, Ohio, was as an auxiliary bishop under Bernardin.

He says the sights he sees as he walks near his residence in downtown Cincinnati convince him of the need to confront social issues.

''When I see people wandering the streets without any place to go and looking for food in garbage cans, that's what makes me ask big questions about our country, our city.''

Asked if women will ever become priests, he says, ''Theologically, I do not believe so. At the same time, this is not a theological belief that I'm willing to die for.''

On priestly celibacy: ''If somebody said to me today, 'Here is a piece of paper. You sign this and we do away with priestly celibacy,' I wouldn't sign. I think priestly celibacy is a very, very imporatant witness in the church. And it may be more important now than it was before, because it's more counter-cultural.''

On Vatican II changes: ''A lot of really dumb stuff is going on in the church occasionally. And people get turned off by that, and rightly so. There hve been some excesses. But the excesses have never been the rule. And I think the contentment rate, with the general tone of the church, is really high.''