Fundamentalism

Coined in early 20th century American Protestantism — specifically a series of pamphlets called The Fundamentals, published 1910-1915, defending core Protestant doctrines against liberal theology and Darwinism. Applied to other religions later.

In common use, 'fundamentalist' has become almost synonymous with 'extremist' or 'radical.' The original meaning is more specific: a return to foundational texts read literally, against the accommodations that more liberal interpretations make with modern knowledge and culture. Fundamentalism exists across Christianity, Islam, Judaism, Hinduism, and other traditions — and within each, it looks quite different.