Philippa Foot, née Bosanquet, was a granddaughter of U.S. President Grover Cleveland. She was born in a small village near Durham, England, and educated at home and at boarding school before attending Oxford University. After graduation, she worked as a researcher at the Royal Institute for International Affairs in London. In 1945, she married Michael (M.R.D.) Foot, the British military historian, and continued to use his surname after their divorce. Returning to Oxford after World War II, she received a master's degree and in 1949 became a fellow of Somerville College, where she was a lecturer in philosophy and served as vice-principal from 1967 to 1969. In the 1970s, she held visiting professorships at various universities in the USA, before joining the Philosophy Department of the University of California, Los Angeles. There she became Griffin Professor of Philosophy and worked until her retirement in 1991, when she was named professor emerita. Philippa Foot was one of the best-known and most original ethicists and moral philosophers of the late 20th century, and is considered one of the pioneers of virtue ethics. She introduced the thought experiment called the trolley problem, which can reveal how we think about morality. She also was a co-founder of Oxfam. Her works included Virtues and Vices and Other Essays in Moral Philosophy (1978), Natural Goodness (2001) and Moral Dilemmas: And Other Topics in Moral Philosophy (2002).