There is such a thing as fanaticism, it is always wrong, and if you disagree, you're wrong too.
Julian Baggini
Fanaticism is overcompensation for doubt.
Robertson Davies
From fanaticism to barbarism is only one step.
Denis Diderot
Fanaticism obliterates the feelings of humanity.
Edward Gibbon
Fanaticism and terrorism have no place in Islam.
Feisal Abdul Rauf
It is not possible to unknow what you do know - the result of that is fanaticism.
Lionel Blue