He was appointed to a professorship in philosophy at the University of Bergen in 1954, but after only one year took a position as professor of applied philosophy at Stockholm University, where he remained until his retirement in 1987.
Han tillträdde en professur i filosofi vid universitetet i Bergen 1954, men efter bara ett år tog han en tjänst som professor i tillämpad filosofi vid Stockholms universitet, där han stannade fram till sin pensionering 1987.