The intersection between the "moderate" (adjective) use and the "moderate" (verb) use is
etymologically interesting. A moderate is one who fails to be a victim of
extremism - although both this description and its opposite, often applied to a
political or social
persona, can be negative, since they indicate adherence to
dogma, as opposed to the practice of constant independent
thought. Nonetheless,
moderates have a reputation for
cirucmspectness, a
laudable quality.
Meanwhile, a moderator moderates a forum, discussion, or process - sometimes a dispute, or a panel. Their specific duties are generally to insure fairness, accuracy, decorum and perhaps pursue the more ephemeral goal of attempting to foster a higher level of intelligence and relevance among those being moderated.
Slashdot is designed to be a self-moderating community, and to a lesser extent, so is Everything. This is accomplished via a difuse moderation model, where a constant semi-random selection of participants share moderation duties. This is novel - moderators are typically individuals appointed via a variety of methods, part of the general belief that moderation is extremely difficult and intellectually demanding.
The driving belief behind moderation in this sense is that we need a defense from our emotional committment to discourse; that the sport of advocacy's logical conclusion is manipulation of the results, rather than ivory tower intellectual competition to determine the fittest truths. Moderators are referees. And our language seems to indicate that their authority stems from standing at the center of a conflict, and perhaps believing both extremes (in a kind of synthesis, or at least, vacancy), or, just plain old straddling the fence - an apt metaphor.
This is at least somewhat pragmatic, since moderates, lacking a powerful attachment to any overriding agenda, are least likely to feel a motivation to fear loss, and thus use insults, rhetoric, or other sleight of hand to distort results.