prof. appiah: the central question in ethics is what is a good life. one perspective on that question is to ask yourself, looking back, towards the end of my life, how will i evaluate myself, how will i think about the value of my life, will i think it has been a meaningful life which i have achieved things worth achieving, helped people worth helping. there is no guarantee that a person who is doing the right thing will necessarily have a large amount of pleasure in their life but what they will have is deep satisfaction that comes to a moral person from knowing they have done or tried to do what was right. terre: trying to do what was right, for some that is as easy as making a pledge. and what a pledge, that is next on "big problems/big thinkers." warren: i could take all my money and do what they used to do in egypt, i could use it to build the biggest tomb ever built, that strikes me as crazy. ms. albright: there is a sense that you are put in this place to do good for people. you should try