What is Fundamentalism?

Fundamentalism is the approach to religion that sees believers embrace an early form of their religion, to consider it beyond criticism and worthy enough to be enforced without having to accommodate modern evidence or logical arguments against it. Fundamentalists of text-based traditions treat a core holy text as infallible and inerrant. Because beliefs are given absolute importance, fundamentalism is often sectarian and intolerant: every doctrinal interpretation results in schism and division.

http://www.humanreligions.info/what_is_fundamentalism.html.