Best known for her famous Trolley Problem, Philippa Foot is one of the most important 20th century philosophers in the field of ethics. She is known for her critique of consequentialism, and for work that led to a new virtue ethics, even though Foot herself did not embrace the movement.[http://lsolum.typepad.com/legaltheory/2010/10/philippa-foot-1920-2010.html cite]
She was known not for a single school of philosophy, but in her method of dealing with philosophical problems. By playing through various novel moral scenarios she was able to discover relations between concepts previously unconsidered, and unexamined elements within moral philosophy.
Listen to this lecture from the London School of Economics on the questions that she wrestled with. [http://media.rawvoice.com/lse_publiclecturesandevents/richmedia.lse.ac.uk/publiclecturesandevents/20130618_1830_onPhilippaFoot.mp3 mp3] [http://www.lse.ac.uk/newsAndMedia/videoAndAudio/channels/publicLecturesAndEvents/player.aspx?id=1934 html]
The Trolley Problem has taken on new significance with the Ethics of Google Car.