Fanatics are picturesque, mankind would rather see gestures than listen to reasons.

A fanatic is a man who consciously over compensates a secret doubt.

In the fevered state of our country, no good can ever result from any attempt to set one of these fiery zealots to rights, either in fact or principle. They are determined as to the facts they will believe, and the opinions on which they will act. Get by them, therefore, as you would by an angry bull; it is not for a man of sense to dispute the road with such an animal.

There is no place in a fanatic's head where reason can enter.

Throughout human history, the apostles of purity, those who have claimed to possess a total explanation, have wrought havoc among mere mixed-up human beings.

The most dangerous madmen are those created by religion, and people whose aim is to disrupt society always know how to make good use of them on occasion.

A fanatic is one who can't change his mind and won't change the subject.

Defined in psychological terms, a fanatic is a man who consciously over-compensates a secret doubt.

The worst of madmen is a saint run mad.

If you see one cold and vehement at the same time, set him down for a fanatic.