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

- Winston Churchill

There are three classes of men; the retrograde, the stationary and the progressive.

- Johann Kaspar Lavater

Thinking about profound social change, conservatives always expect disaster, while revolutionaries confidentially expect utopia. Both are wrong.

- Carolyn Heilbrun

At least two thirds of our miseries spring from human stupidity, human malice and those great motivators and justifiers of malice and stupidity, idealism, dogmatism and proselytizing zeal on behalf of religious or political idols.

- Aldous Huxley

Political extremism involves two prime ingredients: an excessively simple diagnosis of the world's ills, and a conviction that there are identifiable villains back of it all.

- John W. Gardner

Fanaticism consists of redoubling your effort when you have forgotten your aim.

- George Santayana