||Theodore Ryland Sizer was born in New Haven on June 23, 1932. His father, Theodore, was a well-known art historian at Yale. After earning a bachelor’s degree in English from Yale in 1953, the younger Mr. Sizer served as an Army artillery officer, an experience that would determine the course of his professional life.
Few of the young soldiers who served under him had completed high school, but when treated democratically, as members of a cohesive group, they learned new skills readily, he found.
“Whatever troops you got had to deliver,” Professor Sizer told Phi Delta Kappan magazine in 1996. “If one person didn’t do it, he put everybody’s life at stake. That made a deep impression. There was no tracking in the Army, just the beliefs that somehow these young men had to be trained and had to be reliable and that all soldiers can learn.”
After teaching in high schools in Massachusetts and Melbourne, Australia, Mr. Sizer earned two graduate degrees from Harvard, a master of arts in teaching in 1957 and a doctorate in education and American history in 1961. He was a faculty member of the Harvard Graduate School of Education before becoming its dean in 1964. He held the post till 1972, when he became headmaster at Phillips Academy.