SOUTH BEND, Ind. — The Rev. Richard McBrien, a University of Notre Dame theologian known for his unabashed liberal stands on various church teachings and his popular books on Catholicism, died Sunday in his native Connecticut, according to the school. He was 78. The often-quoted theology professor, who for nearly 50 years penned a weekly column for Catholic newspapers, courted controversy with his criticism of Pope John Paul II’s emphasis on orthodoxy, and he advocated for change. McBrien also spoke out in favor of artificial contraception, the ordination of female priests and optional celibacy for priests.

McBrien was highly sought out by reporters seeking comment about the Roman Catholic Church, and he was one of the most widely quoted members since joining the Notre Dame faculty in 1980. He also authored 25 books, the most popular of which were “Catholicism,” which drew criticism from church officials, along with “Lives of the Saints” and “Lives of the Popes.”

His book Catholicism was criticized in 1985, and again in 1996, by U.S. bishops, who said he had presented some core Catholic teachings as one view among many instead of as the authoritative views of the church.

Church officials said the book maintained it was possible for Catholics to believe Jesus Christ could have sinned, indicated that the virgin birth of Jesus probably never happened, and held that homosexuality, contraception and women’s ordination were open questions, with the official church teaching merely being one option.