Fanaticism is a belief or behavior involving uncritical zeal, particularly for an extreme religious or political cause or in some cases sports, or with an obsessive enthusiasm for a pastime or hobby. Philosopher George Santayana defines fanaticism as ""redoubling your effort when you have forgotten your aim""; according to Winston Churchill, ""A fanatic is one who can't change his mind and won't change the subject"". By either description the fanatic displays very strict standards and little tolerance for contrary ideas or opinions.