Islamic fundamentalism (الأصولية الإسلامية, al-oṣooleyyah al-eslaameyyah) has been defined variously as a movement of Muslims who harken back to earlier times and seek to return to the fundamentals of the religion and live similarly to how the prophet Muhammad and his companions lived. Islamic fundamentalists favor "a literal and originalist 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 see "Islamic fundamentalism" as a pejorative term used by outsiders for Islamic revivalism and Islamic activism.
- The term 'fundamentalist', which was coined in 1920, derives from the title of a series of tracts - The Fundamentals - published in the United States from 1910 to 1915. It has since been implicitly defined as meaning a person who believes that, since The Bible is the Word of God, every proposition in it must be true; a belief which, notoriously, is taken to commit fundamentalist Christians to defending the historicity of the accounts of the creation of the Universe given in the first two chapters of Genesis. On this understanding a fully believing Christian does not have to be fundamentalist. Instead it is both necessary and sufficient to accept the Apostles' and/or The Nicene Creed. In Islam, however, the situation is altogether different. For, whereas only a very small proportion of all the propositions contained in the Old and New Testaments are presented as statements made directly by God in any of the three persons of the Trinity, The Koran consists entirely and exclusively of what are alleged to be revelations from Allah (God). Therefore, with regard to The Koran, all Muslims must be as such fundamentalists; and anyone denying anything asserted in The Koran ceases, ipso facto, to be properly accounted a Muslim. Those whom the media call fundamentalists would therefore better be described as revivalists. This conceptual truth not only places a tight limitation upon the possibilities of developmental change within Islam, as opposed to the tacit or open abandonment of one or more of its original particular claims, but also opens up the theoretical possibility of falsifying the Islamic system as a whole by presenting some known fact which is inconsistent with a Koranic assertion.
- The principal tenet of Jainism is non-harming. Observant Jains will literally not harm a fly. Fundamentalist Jainism and fundamentalist Islam do not have the same consequences, neither logically nor behaviorally.
- The only problem with Islamic fundamentalism are the fundamentals of Islam.
- One of the ways Islamic fundamentalists have demonstrated their moral backwardness, bankruptcy and ignorance is through gross human rights violations.
- The objective of these barbaric acts is to terrorise, to paralyse through fear, to subjugate or to censor. Undisputedly after this act that traumatised the whole nation, fear is there. It is my responsibility to say that this fear must be overcome. And to say that this attack must continue to prompt free speech in the face of Islamic fundamentalism. We must not stay silent. And we must say what happened. We must not be scared of words: this is a terrorist act committed in the name of radical Islamism. Denial and hypocrisy are no longer an option. The absolute refusal of Islamic fundamentalism must be proclaimed high and loud by whomever. Life and liberty are among the most precious values.
- The emancipation of women, more than any other single issue, is the touchstone of difference between modernization and westernization. The emancipation of women is westernization; both for traditional conservatives and radical fundamentalists it is neither necessary nor useful but noxious, a betrayal of true Islamic values.
- Bernard Lewis, as quoted in "War Without End: Why Iraq Can Never Be A Stable Democracy" (20 June 2014), by Loren Thompson, Forbes.
- At the end of his long and cantankerous life the maulana had gone against all his high principles. He had gone to a Boston hospital to look for health; he had at the very end entrusted himself to the skill and science of the civilization he had tried to shield his followers from. He had sought, as someone said to me (not all Pakistanis are fundamentalists), to reap where he had not wanted his people to sow. Of the maulana it might be said that he had gone to his well-deserved place in heaven by way of Boston; and that he went at least part of the way by Boeing.
- Fundamentalism is not accidental but essential to Islam. It is inherent in those religious ideologies which are built on a narrow spiritual vision, have a limited psychic base, and which emphasise dogma and personalities, other than experience and impersonal truth. Islam's fundamentalism is rooted in its theology, its founder and his practices. It means that it will also have to be fought there. But this point is ill understood and, therefore, the struggle is at the best of times phoney war.
- Ram Swarup, Swords to sell a god, ( 16 June 1992 in The Telegraph) quoted from Goel, Sita Ram (editor) (1998). Freedom of expression: Secular theocracy versus liberal democracy. 
- The cruelty of Islamic fundamentalism is that it allows only to one people—the Arabs, the original people of the Prophet—a past, and sacred places, pilgrimages, and earth reverences. These sacred Arab places have to be the sacred places of all the converted peoples. Converted peoples have to strip themselves of their past; of the converted peoples nothing is required but the purest faith (if such as thing can be arrived at), Islam, submission. It is the most uncompromising kind of imperialism.
- VS Naipaul, Naipaul VS (1998) Beyond Belief: The Islamic Incursions among the Converted Peoples, Random House, New York page 64
- The term "Islamic fundamentalist "is in itself inappropriate, for there is a vast difference between Christianity and Islam. Most Christians have moved away from the literal interpretation of the Bible; for most of them, "It ain't necessarily so." Thus we can legitimately distinguish between fundamentalist and nonfun- damentalist Christians. But Muslims have not moved away from the literal inter- pretation of the Koran: all Muslims—not just a group we have called "fundamen- talist"—believe that the Koran is literally the word of God. *I have already pointed out that, unlike Protestants, who have moved away from the literal interpretation of the Bible, Muslims—all Muslims—still take the Koran literally. Hence, in my view, there is no difference between Islam and Islamic fundamentalism. Islam is deeply embedded in every Muslim society, and "fundamentalism" is simply the excess of this culture. (185)
- Ibn Warraq Why I am not a Muslim