You face two buttons. Pushing one will destroy Greensboro. Pushing the other will save it. There is no way for you to know which button saves and which destroys. What ought you to do? Answer: You ought to make the correct guess and push the button that saves Greensboro. Second question: Do you have an obligation to push the correct button?

Among analytic philosophers in the past few years there has been a growing commitment to taking Marx seriously. Since the publication in 1971 of John Rawls’ book A Theory of Justice there has been a growing commitment to taking problems of Justice and rights seriously. These two developments intersect in mutual criticism: Marx's radical critique challenges the resources of recent theories of rights and Justice, while the sophistication of recent theories raises the possibility that they escape Marx's most basic criticism.