Is it ok to kill one person to save five? Are there any situations when cannibalism can be justified? If a woman signs an agreement giving her consent to being a surrogate mother and later refuses to part with the child, should the agreement be enforced in a court of law? These and other such moral dilemmas are discussed by Prof. Michael Sandel in a course on justice at Harvard University, all the lectures of which are available here. This is the first course that Harvard has made available for free online viewing.