Extremists and Moderates

Watched "The Weather Underground" documentary last night with rather mixed feelings. On the one hand, sharing the scorn for the "old farts" (see interview with Ayers and Dohrn) that they get from today's students, on the other hand trying to remember how I felt about them back in the day.

An interesting question: do political movements generate extremists naturally, as part of the socio-physics of the movement (rather like any avalanche will scatter boulders at the fringe of the fall while the fine dirt is at the base) or do extremists generate movements--those bold and brazen souls who challenge the establishment and bell the cat encourage the timid mice to think new thoughts and venture away from their hole? Or is "or" a false dichotomy? I suspect the latter, though it's certainly reassuring to visualize extremists as the foam on the waves. [ed--anyone tired of metaphors yet--enough already.]