Andew M. Greeley, the contrarian Roman Catholic priest known for his best-selling novels, scholarship and criticism of church leadership, passed away early Thursday in Chicago. He was 85.

Described as a "maverick", Greeley wrote more than 50 novels. Ten of them appeared on The New York Times best-sellers.

Peter Steinfels of the Times noted that many of his novels were "rife with Vatican intrigue, straying priests and explicit sex."

Greely once said, "Sometimes I suspect that my obituary in The New York Times will read 'Andrew Greeley, Priest; Wrote Steamy Novels'," according to Steinfels.

Yet, said Steinfels, most of the priests in his novels were hard-working, wise and virtuous.

The sex was generally between married couples seeking to reconcile after a period of estrangement, he said.

Elaine Woo of The Los Angeles Times said that although Greeley's novels attracted millions of loyal followers, their provocative plot twists - including pedophile priests, corrupt cardinals and explicit sex - "made others, particularly in the church hierarchy, yearn for a vow of silence from the gadfly in their midst."

Catholic commentator John L. Allen Jr., wrote in the independent National Catholic Reporter newspaper, "The progressive Catholic values of the 1960s informed Greeley's approach, both to secular politics and to the church. Over the years, he supported ordaining married men and women as priests, attacked what he saw as the inflated power of the Vatican, and railed against what he termed the 'original sin' of clerical culture: envy."

Thomas W. Roberts, former editor of the National Catholic Reporter, wrote in The Los Angeles Times a few years ago, "There is a certain truth-telling that goes on in his novels that mirrors the kind of truth-telling that he has brought to the Church as a social scientist. He made us face real facts."

Greeley not only raised the hackles of Catholic Church leadership with his novels, his research also raised the ire of the hierarchy.

In 1972, American bishops rejected a study which they themselves had commissioned in which he found that American priests were widely dissatisfied with their leadership, according to Steinfels.

Greely once called the U.S. bishops "morally, intellectually and religiously bankrupt" and "mitered pinheads."

He also criticized church leaders for their policies on birth control, divorce and the ordination of women.

Furthermore, Greeley clashed with Cardinal John Cody of Chicago and later with Cardinal Joseph Bernardin. Neither ever gave him his own parish.

Earlier, in the 1960s, he displeased liberal Catholics when he wrote of the strength of Roman Catholic schools.

They believed at the time that the schools were inferior and a waste of Church resources.

University of California-Berkeley professor and Greeley co-author Michael Hout said in The Los Angeles Times that the superiority of Catholic school education "is so widely accepted now that it is hard to grasp how new and controversial the idea was then."

Greeley was also a pioneer in rebuking the Church for its handling of its sex-abuse scandals.

He was born in Oak Park, Illinois in 1928 into an Irish Catholic family. He knew by the second grade that he wanted to be a priest.

Greeley attended seminary in Chicago and was ordained in 1952. He served as an assistant pastor of a church in Chicago for a decade.

It was at this time that he began to write books. He published books on young Catholics and church life in the suburbs, according to Steinfels.

Greeley published over 100 works of non-fiction in addition to his novels.

In 1962 he was granted a Ph.D. in sociology from the University of Chicago and became a researcher.

"Father Anthony Greeley was the most influential American Catholic sociologists of the 20th century," said Rev. Tom Reese, a senior analyst at the National Catholic Reporter.

Greeley had been in ill health since an accident in 2008. He was seriously hurt when his jacket got caught in the door of a taxi in Chicago as it pulled away. He was thrown to the pavement and received a brain injury.

He is survived by a sister, five nieces, and two nephews.