Islamic fundamentalism ( (uṣūl), the "fundamentals"), has been defined variously as a movement of Muslims who hark back to earlier times and seek to return to the fundamentals of the religion; who favor "a literal interpretation" of the primary sources of Islam (the Quran and Sunnah), and seek to eliminate (what they perceive to be) "corrupting" non-Islamic influences from every part of their lives; and as a pejorative term used by outsiders for Islamic revivalism and Islamic activism.