Fundamentalism is a controversial issue. The social scientists who accept the concept and take a global, comparative approach are divided: some interpret the phenomenon as an expression (or the quintessence) of modernity; others see it as a reaction to modernity. This is part of a broader debate in social theory on the classical dichotomy between tradition and modernity, postmodernity and globalization. Fundamentalism and terrorism differ in principle, but the latter sometimes becomes a sort of senile disease of the former. The violent radicalization of some fundamentalist groups very often occurs when their fundamentalist project to gain political power or impose their cultural hegemony over society fails. Religious violence intensifies when those in power suppress such groups by violent means, prompting them to go underground, take up arms and use terrorist attacks to combat the political establishment. The holistic worldview very often degenerates into cleansing schemes to eliminate religious minorities or ethnic groups.