Abstract

Lecture II first considers Thomson’s proposal for why many people believe—mistakenly, she thinks—that a bystander may turn the trolley. It then considers an alternative proposal, and a possible justification of it, that would explain why both the conductor and the mere bystander may turn the trolley, thereby killing someone else. The principle focuses on how the trolley comes to be turned or otherwise stopped from killing the five. While some criticisms of the principle are presented, the lecture considers how something like this principle relates to the moral distinction between killing and letting die, and whether crucial parts of it can help justify sometimes killing more people to save fewer. The lecture concludes by considering whether cases that involve redirecting a threatening agent rather than a device should be considered as “trolley problems.”