Phillippa Ruth Foot (1920–), who is the granddaughter of U.S. President Grover Cleveland, opposes subjectivism or emotivism in ethics and insists on a connection between morality and rationality. She has tried to undermine a fact/value divide in claiming that moral judgments are determined by facts about our lives and nature. In this sense, she is a “moral naturalist.” Moral naturalism is the view that what is morally good is not some distinct and special quality but ordinary things and actions that have been rationally chosen as best in a particular set of circumstances.

Overall, Foot has consistently supported virtues as conducive to self-interest. Her main publications are Virtues and Vices and Other Essays in Moral Philosophy (1978), Natural Goodness (2001), and Moral Dilemmas: And Other Topics in Moral Philosophy (2002).