Noah Millman continues the discussion on Brooks and “moderation”:

If I had to offer a working definition of a “moderate,” it would be: someone whose allegiance to her political community trumps her allegiance to her political tendency. And an extremist would be the opposite, someone whose definition of her political community is defined by her political tendency rather than by the historic shape of the political community as it actually exists.

This is an interesting definition, but I’m not sure that it gets us any closer to making a useful distinction between the two. Most political tendencies and persuasions include the assumption that theirs is the reasonable, sane, moderate one that best serves the common good or national interest. The more completely another persuasion is opposed to it, the more “extreme” or “radical” it will be perceived by the first persuasion’s adherents. Especially in the modern age, adherents of almost every political persuasion like to identify themselves as the popular or representative persuasion that is opposed to a group that represents a narrow factional interest.

There is always the temptation to assume that one’s political opponents are less scrupulous and more willing to put allegiance to party or faction ahead of allegiance to community or country. Maybe a few of them are in certain cases, but that isn’t usually what separates the extremist from the moderate. What usually separates extremists and moderates are their different ideas about what sorts of acts and policies can be justified in the name of the political community. As a rule, an extremist will have fewer qualms about using coercion and violence to achieve his ends, he will be more willing to ignore legal and moral prohibitions that get in the way, and he will be less inclined to respect established limits. For instance, someone representing a more oligarchic faction might have a narrower, more restricted view of the political community, but we would identify him as an extreme oligarch rather than a moderate one according to the abuses he was willing to endorse in order to preserve an oligarchic regime.