Johann Baptist Metz, one of the most influential Roman Catholic theologians of the 20th century and a pioneer of Jewish-Christian dialogue in the aftermath of the Holocaust, died on Dec. 2 in Münster, Germany. He was 91.

His death was confirmed by the University of Münster, where he taught for many years.

Professor Metz, an ordained priest, believed that the church must be aligned with the victims of history, and he devoted his work to building solidarity with the oppressed. He challenged German Catholics to face the reality of Auschwitz when many did not.

“Articulating others’ suffering is the presupposition of all claims to truth,” Professor Metz said when he received an honorary doctorate from the University of Vienna in 1994. “Even those made by theology.”

Thanks to Professor Metz, the Catholic Church in West Germany formally addressed the Holocaust for the first time. He pushed the German bishops to discuss it in a statement he drafted for a synod, or special council, in Würzburg from 1971 to 1975.