Fanaticism is an emotion of being filled with excessive, 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.
The difference between a fan and a fanatic is that while both have an overwhelming liking or interest in a given subject, behaviour of a fanatic will be viewed as violating prevailing social norms, while that of a fan will not violate those norms (although the person may be considered unusual). A fanatic differs from a crank, in that a crank is defined as a person who holds a position or opinion which is so far from the norm as to appear ludicrous and/or provably wrong, such as a belief in widespread alien abduction. In contrast, the subject of the fanatic's obsession may be "normal", such as an interest in religion or politics, except that the scale of the person's involvement, devotion, or obsession with the activity or cause is abnormal or disproportionate.
Podium: We Must Try to Contain Fanaticism ; AMOS OZ from a Lecture Given by the Prominent Israeli Novelist for the BBC Radio 3 Series `Sounding the Century'
Oct 21, 1999; I'M AN expert on comparative Fanaticism. I don't mean just the obvious manifestations of fundamentalism or zealotry; I...