Raised and educated in Adelaide, South Australia, John Davis taught History, Australian Studies and Theory of Knowledge at Pembroke School, Kensington Park, and is a life member and a former trustee. He is the author of Principles and Pragmatism, a history of Pembroke School and its antecedents - Girton Girls' School and King's College. In retirement, he volunteered at the History Trust of South Australia and at Pembroke School. In 2014, the school published his updated second edition of Principles and Pragmatism. When researching the history of Girton in 1989, he first learned of Harry Hodgetts and his intriguing life story.