Ralph McInerny, a longtime professor of philosophy and medieval studies at the University of Notre Dame who also was a popular mystery writer best known for his "Father Dowling" series of novels, has died. He was 80.

McInerny died Jan. 29 at Our Lady of Peace Hospital in Mishawaka, Ind., after a long illness, according to the university.

A member of the Notre Dame faculty from 1955 until his retirement in 2009, McInerny gained international renown as a scholar, author and lecturer who specialized in the works of St. Thomas Aquinas, the 13th-century theologian and philosopher.

McInerny, who also wrote and lectured on ethics, philosophy of religion and medieval philosophy, directed the university's Medieval Institute from 1978 to 1985.

And from 1979 to 2006, he directed its Jacques Maritain Center, which is primarily an archive for the study of materials related to the 20th-century French Catholic philosopher and his influence in the United States.

McInerny "was one of the leading scholars worldwide on the philosophical thought of Thomas Aquinas," said John O'Callaghan, an associate professor of philosophy who replaced McInerny as director of the Maritain Center.

And then there was McInerny, the prolific author of approximately 100 novels.

Beginning with "Her Death of Cold" in 1977, he wrote more than two dozen mysteries featuring Father Dowling, which led to the 1989-91 "Father Dowling Mysteries" TV series starring Tom Bosley.

Father Dowling

is "a priest detective whose secular interest in crime is merely a mask for his deeper concern for the spiritual welfare of the victims and criminals involved," wrote James R. McCahery in the "St. James Guide to Crime & Mystery Writers."

Among McInerny's other series are the "Andrew Broom" mysteries, the "Sister Mary Teresa" mysteries (under the pseudonym Monica Quill), and the "University of Notre Dame" mysteries featuring Roger Knight, a Notre Dame professor, and his brother Philip, a semi-retired private investigator.

In 1993, McInerny received a Lifetime Achievement Award at the Bouchercon World Mystery Convention.

"Stained Glass," his final Father Dowling mystery, was published in October 2009. "Sham Rock," his final mystery featuring the Knight brothers, will be published in April.

"Looking back at his career, you see just how prolific he was," said Matt Martz, an associate editor at St. Martin's Press who was McInerny's editor for the Father Dowling and Knight mysteries the last two years.

Born Feb. 24, 1929, in Minneapolis, McInerny served a stint in the Marine Corps from 1946 to 1947.

He earned a bachelor's degree from St. Paul Seminary in St. Paul in 1951, a master's degree from the University of Minnesota in 1952 and a doctorate in philosophy from Laval University in Quebec in 1954.