The discussion of Kant from last lecture continues with a statement and explication of his first formulation of the categorical imperative: act only in such a way that you can will your maxim to be a universal law. Professor Gendler shows how Kant uses the categorical imperative to argue for particular moral duties, such as the obligation to keep promises. In the second part of the lecture, Philippa Foot’s Trolley Problem is introduced, which poses the problem of reconciling two powerful conflicting moral intuitions. A critique of Foot’s solution to the problem is explored, and the lecture ends with Judith Jarvis Thomson’s proposed alternative. Complete course materials are available at the Open Yale Courses website: http://oyc.yale.edu This course was recorded in Spring 2011.