Obituary of Sylvester Theisen

Sylvester Peter Theisen

Date of Death: March 18, 2024

Dr. Sylvester Theisen died peacefully on March 18, 2024, at home in St. Joseph, at the age of 99.

Born August 22, 1924, on a farm near Cold Spring, Minnesota, Sylvester (“Sy”) was the eighth of ten children of Math and Catherine (Kinzer) Theisen. After graduating from St. Boniface High School, Sy was the first in his family to attend college. He went to St. John’s University, and then graduate school at the University of Notre Dame, where he earned a doctorate degree in sociology.

While working overseas, he met Vera Castelli, and they were married on April 10, 1956, in Germany. They settled in Minnesota, where Sy was a professor at St. John’s University for more than 45 years. During that time, he took part in many international conferences, and he published nearly a hundred book reviews and essays. Sy was a dedicated teacher who was passionate about learning, and he became a friend and mentor to many former students.

From 1969 to 1972, Sy was a full-time administrator, in charge of uniting the academic departments and administrative functions of the College of St. Benedict and St. John’s University. He envisioned and implemented the unique coordinate system under which they operated until very recently. He also served as the Academic Vice-President at St. John’s for several years.

Sy was a voracious reader and great conversationalist. He had a gift for storytelling, and an amazing memory for detail. Friends and family enjoyed hearing stories of his childhood and his travels to over 50 countries around the world; many of those stories are chronicled in his autobiography, Sylvester’s Story: Von Stearns County Aus. 

His wife, Vera, died in 2020. Sy will be lovingly remembered as a kind and generous man by his nine children: David (Terri Bouressa), Clara (Tim Weitz), Sylvia, Paul (Naomi Niwa), Julia (John Shine), Andre (Ann Peters), Bruno (Ann Schuetz), Carlo, and Marcel (Ana Claudio Fernández); eleven grandchildren: Saul Theisen (Dana Kernik-Theisen), Maria Theisen (Kevin Ellingwood), Brian Weitz (Kara Bancroft), Laura Weitz, Michelle Weitz, Caitlyn Davison (Ben), Tanner Shelp, Leo Theisen, Nina Theisen, Marco Theisen Claudio, and Ruben Theisen; and three great-grandchildren: Lowell Davison, Anna Davison, and Iver Kernik-Theisen.

A celebration of life will be held this summer. The family thanks the staff at Moments Hospice for the excellent care they provided. Memorials are appreciated to Moments Hospice Foundation, or to a charity of your choice. 

Sy’s favorite Bible verse that he lived by: Act justly. Love tenderly. Walk humbly.