Is Habermas' Final Unanimity Possible?

My major project for the summer is to work systematically through the works of sociologist Jürgen Habermas. This will eventually lead me to an empirical study of the family culture of the knowledge class vs. the corporate class.

Today I want to start with a vision that he presents in his earliest major work, The Structural Transformation of the Public Sphere (1962). He argues that the "public sphere" was born in the English coffeehouses of the mid-1600s. In our day, however, the spinmeisters have turned public opinion into manipulated propaganda. (Ok, he doesn't really say spinmeisters, but that is what he means.) In a truly rational society, though, he thinks that the public sphere should produce

the final unanimity wrought by a time-consuming process of mutual enlightenment, for the "general interest" on the basis of which alone a rational agreement between publicly competing opinions could freely be reached.

Can society have a "final unanimity?" Can there be a rational agreement between publicly competing opinions? Habermas is Marxist enough to assume the possibility of an objective conflict of interests among social classes. Yet he is liberal enough to believe that these interests and the broader difference of opinions that lie beyond interest can be reconciled with enough conversation.

What Habermas does not assume is a Calvinist expectation that our pride, fallenness, and sin will always prevent unanimity, this side of the Second Coming. He does see that different people have different interests. He does not see, though, that people sometimes perversely pursue opinions and desires that are objectively against their own interest.

I can't tell whether his argument is with a specifically Christian understanding that sin distorts our understanding of what is good, or with the larger foundation of Western philosophy that we really do have a good. More reports as I work through his body of work.