Photo courtesy of Saint John’s Abbey
Father Wilfred (Robert John) Theisen, born on September 5, 1929, in Wadena, Minnesota, was one of nine children. After losing his father at the age of four, he pursued a vocation inspired by the Benedictine Sisters and monks. He attended Saint John’s Preparatory School, graduating as valedictorian in 1947, and later joined Saint John’s Abbey, professing vows in 1950 and becoming a priest in 1956.
Father Wilfred earned a master’s in physics (1962) and a PhD in the history of science (1972). He taught physics at Saint John’s University for over 40 years and served as Professor Emeritus. His contributions extended beyond teaching: he worked with the Collegeville Institute for Ecumenical and Cultural Research and Hill Monastic Manuscript Library and served as chaplain to Benedictine Sisters.
He had a deep interest in the relationship between religion and science, particularly the Catholic Church’s response to Darwin’s theory of evolution. A gifted homilist, he often addressed complex ecclesiastical issues.
Father Wilfred enjoyed golf, university sports, and editing medieval alchemical texts. Known for his warm hospitality, he maintained strong ties with alumni and friends. He passed away on December 3, 2024, at Saint John’s Abbey. May God reward him.