By fanaticism we usually mean two things. One is that someone is dedicated in the extreme to their cause, belief, or agenda, willing to live and die and maybe kill for it, as John Brown was. The other is that the cause, belief or agenda is not ours, and in 1859 John Brown's beliefs were not those of most Americans. No one calls himself or herself a fanatic. It's what you call people who are weird or threatening, extremists in the defence of something other than your own worldview. I've been around activists all my adult life, and though it's popular to think the world gets changed by delightful people, a lot of the saints and agents of change are obsessive, intransigent, unreasonable, and demanding, of themselves and of us. That's what it generally takes to change the world. Gandhi knew this when he said, "First they ignore you, then they laugh at you, then they fight you, then you win."
While John Brown's methods were extreme, the then-radical idea that slavery is "an intolerable evil" is something accepted by society at large today. "Maybe," she concludes, "we should all be a little more--not fanatical, but unreasonable and intransigent in our commitment to truth, to justice, to a better world."
Where is the line between vision and extremism? John Brown and Gandhi, of course, would have disagreed over the use of violence. So the question remains: Is fanaticism always wrong?