Stanford professor emeritus of education Nathaniel Gage passed away on Aug. 17; he was 91.

Gage retired two decades ago, but was still active in his field — he had just finished writing a book, A Conception of Education, that will be published this year.

Gage’s many accomplishments include co-founding the Stanford Center for the Research and Development in Teaching, being elected to the National Academy of Education and winning the E. L. Thorndike Award for Career Achievement in Educational Psychology from the American Psychological Association.

“Nate came into the office every day right up to his final days,” Dean of Education Deborah Stipek told the Stanford News Service. “I kidded him about being my most conscientious faculty member. He kidded me about being the prettiest dean he’d ever had and the only one he’d ever kissed — on the cheek, of course. He was devoted to his work and to Stanford. It is hard to imagine the school without him.”

A memorial service for Gage will be held at Stanford in early November.