WHEN liberals are in a philosophical mood, they like to cast debates over the role of government not as a clash between the individual and the state, but as a conflict between the individual and the community. Liberals are for cooperation and joint effort; conservatives are for self-interest and selfishness. Liberals build the Hoover Dam and the interstate highways; conservatives sit home and dog-ear copies of “The Fountainhead.” Liberals know that it takes a village; conservatives pretend that all it takes is John Wayne.

In this worldview, the government is just the natural expression of our national community, and the place where we all join hands to pursue the common good. Or to borrow a line attributed to Representative Barney Frank, “Government is simply the name we give to the things we choose to do together.”

Many conservatives would go this far with Frank: Government is one way we choose to work together, and there are certain things we need to do collectively that only government can do.

But there are trade-offs as well, which liberal communitarians don’t always like to acknowledge. When government expands, it’s often at the expense of alternative expressions of community, alternative groups that seek to serve the common good. Unlike most communal organizations, the government has coercive power — the power to regulate, to mandate and to tax. These advantages make it all too easy for the state to gradually crowd out its rivals. The more things we “do together” as a government, in many cases, the fewer things we’re allowed to do together in other spheres.