Gass started his long teaching career as an instructor of philosophy at The College of Wooster, 1950-54. Then he moved to Purdue University, where over fourteen years (1955-69) he moved from assistant professor to associate professor to full professor in the philosophy department there. He was also a visiting lecturer in philosophy and English at the University of Illinois, 1958-59.

Click on the above links to see materials covering Gass' career as a professor of philosophy at Purdue University and Washington University in St. Louis.