The history of Islamic Principlism in Iran covers the history of Islamic revivalism and the rise of political Islam in modern Iran. Today, there are basically three types of Islam in Iran: traditionalism, modernism, and a variety of forms of revivalism usually brought together as fundamentalism. Neo-fundamentalists in Iran are a subgroup of fundamentalists who have also borrowed from Western countercurrents of populism, fascism, anarchism, Jacobism and Marxism.
The term Principlists, or Osoulgarayan, is an umbrella term commonly used in Iranian politics to refer to a varieties of conservative circles and parties. The term contrasts with reformists or Eslaah-Talabaan who seek religious and constitutional reforms in Iran.
"Fundamentalism is the belief in absolute religious authority and the demand that this religious authority be legally enforced. Often, fundamentalism involves the willingness to do battle for one's faith. Fundamentalists make up only one part of any religion's followers, who usually fall along a wide spectrum of different interpretations, beliefs and strong values."
There are some major differences between Christian fundamentalism and what is called Islamic fundamentalism. According to Bernard Lewis:
"In western usage these words [Revivalism and Fundamentalism] have a rather specific connotation; they suggest a certain type of religiosity- emotional indeed sentimental; not intellectual, perhaps even anti intellectual; and in general apolitical and even anti-political. Fundamentalists are against liberal theology and biblical criticism and in favor of a return to fundamentals-i.e. to the divine inerrant text of the scriptures. For the so call fundamentalists of Islam these are not and never have been the issues. Liberal theology have not hitherto made much headway in Islam, and the divinity and inerrancy of the Quran are still central dogmas of the faith ... Unlike their Christian namesakes, the Islamic fundamentalists do not set aside but on the contrary embrace much of the post-scriptural scholastic tradition of their faith, in both its theological and its legal aspects."