The term "fundamentalism" was coined in the United States in the 1920s to designate conservative offshots of evangelical Christianity, uncompromising in their biblical literalism and inerrancy, and their exhortations to return to the biblical, spiritual, and moral injunctions and conceptions of an ideal society and World order, all based on the idea that the World has fallen into a state of spiritual decay. Originally the term was applied solely to the theological movement in the late 19th and early 20th centuries among American and British Protestants who defended orthodox beliefs and attacked liberal theology and historical criticism, but since 1920s term also designated a wider cultural movement that vigorously protested many social changes identified with modernism, as well as incorporating the latest scientific development in public education. The most famous controversy was over acceptance of evolution since fundamentalists insisted on the historical accuracy of the biblical account of creation. In the following decades the interpretations given the fundamentalist movement have changed and were mostly associated with anti-intellectualism and social anti-modernism, gradually became in the American popular imagination a pejorative and often demonizing label for various religious and political movements around the World.
Christian fundamentalism thus originated and developed in the unique context of American religious pluralism and the separation of church and state, conditions which do not apply elsewhere. However, from the mid-20th century the term fundamentalism was occasionally used to describe even non-Christian movements, namely Hindu and Islamic. The first usage in relation to Islam appeared in a letter written in May 1937 by Reader Bullard, British minister in Saudi city of Jeddah, who stated that King Abdulaziz ibn Saud "has been coming out strong as a fundamentalist" by condemning public mixing of men and women. The term "Islamic fundamentalism" was coined in 1949 by Hamilton Alexander Rosskeen Gibb, a Scottish historian and orientalist, with reference to the Salafi movement of Jamal al-Din Asadabadi and Rashid Rida, and the Muslim Brotherhood. With the rise of Islamic political self-consciousness, especially in Iran after the overthrow of the Shah in 1979, the term developed a new reference and it was effectively displaced from evangelism and transferred totally to Islamic movements. This shift occured in both the popular and scholarly media, the one reinforcing the other, while Christian evangelism ceased to be fundamentalist and instead was reclassified descriptively in such terminological labels as televangelism or the religious right.
Considering Christian fundamentalism is characterized by literal interpretation and inerrancy of scripture, and associated with rejection of modern society and science, the transference of a term to Islamic religious and socio-political movements (i.e. Salafism, Wahhabism, the Muslim Brotherhood, Khomeinism) in most cases is not only confusing but also misleading, contradictory and unambiguously wrong by all means. If fundamentalism means the acceptance that the Quran is the absolute Word of God and free of human error, then all Muslim believers would have to be considered "fundamentalists". Starting with the interpretation of sacred scriptures, we should distinguish literalism and inerrancy (along with infallibility), as well as differences between Christian and Islamic exegesis. Mainstream Christianity uses the historical-critical method, in contrast to fundamentalist approach that teaches the Bible lacks error in every way in all matters: chronology, history, geology, biology, sociology, psychology, politics, and so on. In Islam, the Quran's normative status is inviolate and thus different from the Bible's normative status in Christianity (its more akin to Jesus's status), but that does not mean that the way Muslims understand the text is set in stone, nor does it render the message of the Quran beyond debate. There are numerous movements and schools of Islamic theology among major denominations (Sunni and Shia), many tafsirs of the Quran and hadiths, all using various methods of interpreting.
The most akin Islamic movements to Christian fundamentalism would be Wahhabism, Atharism and Akhbarism, since they all reject rationalistic Islamic scholastic theology (kalam) in favor of strict textualism in interpreting the Quran and Sunnah. As in the case of their Christian counterpart, both Akhbarism and Wahhabism represent relatively young movements, the former as the reform stream from the 18th-century Sunni Arabia and the latter as the dissident movement from 17th-century Shia Iran. They both also form a historical and contemporary minority within two major denominations. On the other hand, Atharism has a historical tradition dating back in the 8th century, but it has always been marginalized by Maturidism, the predominant theological orientation among Sunni Muslims. When examining their and rival nature, there are many theological, terminological and semantic challenges.
First of all, Quran itself invites readers to reflect and interpret its verses, both those that are self-evident in their meaning and those that are metaphorical and difficult to decipher, so a "return to fundamentals" hardly implies strict textualism. There are basically three types of Salafism, all advocating a return to the traditions of the Salaf (the first three generation of Muslims): classical Salafism (Atharism), modernist Salafism and Saudi Salafism (Wahhabism). Obviously, orientalist Gibb equated the Salaf with "fundamentals" in order to simplify Arabic vocabulary for a Western audience, however, he did not refer to rigid theological movements (Atharism and Wahhabism) but modernist Salafism of Asadabadi and Rida. Those thinkers sought to reconcile Islam with modernism, found inspiration in glorious times of early Islam, and called for wholescale religious reforms because they saw their contemporary religion as decadent and corrupt. Like Wahhabis, they were reformists and their ideas also involved a radical, in some cases an armed, defence of a religious tradition, but far from rejecting modern influences.
Salafism thus cannot be described as anti-modernist, althought the word "salafi" is sometimes used for "fundamentalist" in Arabic. An alternative Arabic term, "usuli" (from "usul" or roots) corresponds more closely to "fundamentalism" in English. Another complicating factor here is that specific usage "usuli" has acquired in the religious history of Shiism, as Usulism represents predominant theological school and rival to Akhbarism. Unlike rigid Akhbaris, the Usulis believe in independent ijtihad or reasoning, favor the creation of new rules of fiqh and balance adherence to scripture with an emphasis on religious leadership. Through descibed in the Western media as a "fundamentalist", the leader of the 1979 Iranian revolution, Ayatollah Khomeini, belonged to the Usuli school as a senior member and strongly opposed the Akhbari dissenters. Many liberal and progressive Muslims would describe themselves as usulis, without thinking that this carries a negative connotation, along with Iranian conservative principlists who call themselves "usul gara" which literally means "fundamentalist", but in a positive sense. During the Iranian revolution, some supporters of Khomeini proudly coined a new word "bonyadegar", by translating literally the English term "fundamentalist", and used it when describing themselves.
Speaking of "rejecting of modernity" and "returning to roots", widely atributed to so-called Islamic fundamentalist movements mentioned above, that would be correct only if both concepts are carefully elaborated. Indeed, all movements emerged as a reaction to "modernity", reflecting an actually existing contemporary situation. In the Wahhabi case it implies religious pluralism, in the modernist Salafi case foreign imperialism, and in Iranian case socio-political issues (corrupted royalist elite and mobilization of oppressed). Wahhabis were certainly fundamentalists in the way they sought to return not only to alleged scriptural roots but also to accompanying Arabian customs and traditions. They directed their attacks mostly against Sufis and Shias, even ordinary Sunnis, and razed many historical sites. Rise of their reform movement was actually purely political in nature, without any serious social changes, but it can also be described as rigorously counter-modernist because until the 20th century they rejected even modern technology. On the contrary, modernist Salafist movement was dedicated to combating British imperialism, but far from unequivocally opposing the Enlightenment they absorbed the modernist spirit and newest scientific theories (like evolution).
Khomeini, too, frequently stressed that Muslims needed to import such essentials as technology, industrial plants, and modern civilization (tamaddon-e jadid). His closest disciples often mocked the "traditionalists" (sunnati) for being "old-fashioned" (kohaniperast). Hojjati-Kermani, one of such disciples, labeled traditionalists as reactionary and argued they want to return to the age of the donkey. Such concepts and the terminology make mockery of the Orientalist claim that Khomeinism is merely another recurrence of the old traditionalist "epidemic" that has plagued Islam. In both modernist Salafist and Khomeinist case, calls to return to Islam's pristine roots definitely doesn't imply anything socially or technologically regressive, it can be understood only as the glorification of the past and as appeal for renewal a glorious reputation.