I see I opened a whole can of worms with my "trick" question. In fact, I meant to and I think trick questions are sometimes fun!
However, if we are going to talk sensibly about these issues, we have to get a few things straight to begin with--define some terms, so to speak. Sadly, I'm not a very good philosopher, because while I think we should start at the beginning, I'm not quite sure where the beginning is! My best guess, however, is that we have to discuss a bit what we mean by "society" and "common good." Now, Geoff has stated that the common good is nothing more than the sum total of all the private goods of the individuals that comprise a society. Indeed, a society is merely a collection of individuals. What is central here? The individual, it seems. This is clearly reflected in the ideas of liberalism as well. Do we have any alternatives to defining society, the common good, the whole project of human life as lived in common, on the basis of individual liberties? Would it necessarily pierce a shaft into our freedom if we did not talk about it as the main purpose of societal structure? And what do we mean by freedom? This last is a big one, and for now I am just throwing out some questions for consideration. More later!