Moral philosopher who was a member of the University of Michigan's philosophy department for 41 years and its chair for 14 years.
He initially attended and graduated from Calvin College, which was an offshoot of his family's denomination the Christian Reformed Church. He then studied at Harvard and the University of Cambridge where he focused on ethics.
He played a pivotal role in fighting for academic freedom during the 1950s Red Scare when Joseph McCarthy was looking to purge Communists from all facets of American life.
His mother passed away when he was nine. His father was a farmer and a politician. He married Sadie Roelfs in 1934, and they remained married for 44 years.
He studied with several notable philosophers, including William Henry Jellema and Alfred Whitehead.