Fanaticism is a noun descripting a fanatic character, spirit, or action. It can be used only as such. Ex., "Adolf Hitler exhibited a form of Anti-Semmetic fanaticism." or "The church was hurtled into inappropriate fanaticism."

G. Vale has written:

'Fanaticism' -- subject(s): Fanaticism

Joseph Rudin has written:

'Fanaticism' -- subject(s): Fanaticism

try either extremism or fanaticism

When Islamic fundamentalists demanded the death of Salman Rushdie because his novel questioned their faith, world opinion condemned them for their fanaticism.