The dualism between public and private seems to take full force in political discussions. There are those decisions which are completely up to me and those decisions which are up to "all of us," for which one might have various conceptions. I find dualistic thinking in this area extremely damaging, for two reasons. First of all, it forces us to divide people into two kinds: those who want more freedom for the individual in his private sphere, and those who want more unity and collective action in the public sphere. You can nuance this as much as you want--maybe on some issues we need more individual freedom, on others we need more collective action, etc. But I say no matter how much you nuance it, it's still wrong. I'll explain way momentarily.
The second reason why this dualism is extremely damaging is that it gets glued to the left-right dualism. In modern political discussions, it seems that "left" means "fights for the public" while "right" means "fights for the individual." Of course one can immediately point to so many counterexamples that I will refrain from listing them. But if you're thinking in terms of right and left in the first place, that's already a setback to rational discussion.
Reality is far more complex than the public/private dualism can ever explain. What is my "private" sphere? Is it the sphere in which I can behave without obligations? Where exactly is that sphere? I find I have obligations wherever I go. From birth I have had certain obligations to my family, then to my friends, my school, my church, and other institutions which helped shape me. And, of course, I have always had certain obligations to government. A life without obligations is most likely a life lived on a deserted island, and even though, one finds that nature itself has a way of obliging us.
Conversely, what is the "public" sphere? Is it the sphere in which all of us cooperate together? Which sphere is that? Through the market, I am able to cooperate with people I have never met, whose language I cannot even speak, and whose values are probably not my own. In other words, through a series of individual actions not obviously connected with one another the human race has learned to work collectively to create fantastic innovations in both technology and culture. Yet we don't consciously work together to do it. By contrast, when I am forced to pay taxes, am I really working with others? Since I have already listed some of the many institutions to which I have obligations, need I repeat how many different "public" spheres I already indwell?
The devastating affect of this dualism is that we have trouble imagining any more than a few ways in which people actually cooperate. Political unity, in particular, does not always mean effective cooperation, and effective cooperation does not always require political unity. If anything, I suspect an excess of unity and conformity is a hindrance to effective cooperation, and we should always do our best to warn against it.