Nursi emphasized the importance of scientific knowledge in raising religious consciousness.
Nursi's death 44 years ago splintered the movement into several different groups. The most important of these groups today is led by Fethullah Gulen, a former state-appointed Muslim preacher who presides over some 3 million followers and as many sympathizers across the world.
There seems to be no firm consensus on how to define the Gulen movement. Some experts use the word "revivalist" to describe it. But others disagree.
Thomas Michel, who serves as secretary for the Inter-Religious Dialogue of the Society of Jesus in Rome, knows the Gulen community well. This Jesuit priest, who has spent many years teaching theology in Turkish universities, believes the word 'revival' may be misleading.
"I would hesitate to use that term -- 'revival' -- because it kind of is an emotionally charged [term] that gives the impression of other kinds of movements. [This] movement is not a revival in the sense of going back to anything, no. It is a way to try to be a religious believer in today's modern world. [Gulen and his followers] are very conscious that they are living, if anything, in a postmodern age. How does one be a religious believer in this kind of a world? That's the challenge they pose to themselves."
Like his mentor Nursi, Gulen was born in Turkey's conservative and nationalist stronghold of Eastern Anatolia. Educated in a traditional madrasah (religious school), Gulen began his career in the early 1950s as a vaiz, or state-appointed preacher. According to his autobiography, he moved to Edirne in 1958 where he earned a living by giving informal religious lectures.
In the mid-1960s, Gulen obtained a new assignment in a suburban area of the Aegean coastal city of Izmir. There, he laid the foundation of what would become widely known as the fethullahci community -- or community of Fethullah's followers -- a name Gulen himself opposes.
In the 1970s he was arrested and served a seven-month jail sentence on charges of propagating Islamic views. That did not prevent him from supporting the 1980 military coup that temporarily brought Turkey's democratization process to a halt.
Despite the military's efforts to counter the spread of Communism with the help of Islam, Gulen once again faced prosecution for religious propaganda in the early 1980s. But this time he was not arrested and was even authorized to leave for the United States.
Gulen is said now to divide his time between the U.S., where he often goes for medical treatment, and Turkey.
The 66-year-old, soft-spoken religious thinker leads a semireclusive life, devoted to writing, giving interviews to select journalists, and recording audiotapes, which are distributed to his followers worldwide.
The political and economic liberalization that started under President Turgut Ozal in the late 1980s enabled the Gulen movement to blossom and become one of the most powerful socioreligious movements of contemporary Turkey.
Today, the Gulen community controls a nationwide media empire that includes a television channel (Samanyolu TV), a radio station (Burc FM), a daily newspaper ("Zaman"), a weekly magazine ("Aksyon"), and several other periodicals. It also owns a bank (Asya Finans) and is linked to a number of business groups and many prosperous entrepreneurs who help fund many of its endeavors, especially in the field of education.
Father Michel says Gulen's efforts to reconcile Islam, science, and modernity appeal to a large section of Turkey's secularly educated youth.
"I think what [the movement] represents is the desire of many, especially young people -- it is a young movement -- to live out their Islamic faith in the modern settings of modern Turkey. I think this is what they find really attractive and important in the teaching of Fethullah Gulen. It gives them a way that they can be both modern and Muslim at the same time."
Gulen's views that science and religion are compatible are regularly discussed in "Sizinti," the community's scientific journal. Hocaefendi, or Respected Master -- as the religious leader is called by his followers – discusses science in a video message posted on his website.
"Since science is possible only through knowledge, those who neglect learning and teaching are counted to be dead even though they are living. For man has been created to learn and communicate to others what he has learned. Right decisions depend on having a sound mind and on sound thinking. What illuminates and develops the mind is science and knowledge. For this reason, a mind deprived of science and knowledge cannot reach the right decisions and is always exposed to deception and subject to being misled."
Drawing from Nursi's teaching, Gulen believes it is possible to breed a new generation of Muslims who can be fully integrated into today's modern world. This so-called "golden generation" will, in turn, instill moral values into society with a view to eventually being able to influence state behavior.
Gulen's educational projects started in the 1960s when he set up religious summer camps near Izmir. Later on, he established teaching centers (dershane) to help prospective students enter university.
The Gulen group now supervises a network of about 150 schools in Turkey.
These institutions operate under strict government control and teach the same secular, religion-free curriculum as that of state schools. What makes them different is the quality of training offered to students and a strong emphasis on morals, science, and self-discipline.
Father Michel says Gulen's views on education have developed as a response to the challenges posed by the demands of the changing world:
"[Gulen] certainly does emphasize education and I think the problem, as he reads Turkish history in this past century, [is] that Turks, and Muslims in general, had the possibility of only certain kinds of education: either they could go to the old Sufi schools where they were getting spirituality, but not much relevance to modern life; or they could go to a military-type education where they were getting discipline, but maybe not so much in terms of moral values; or they could go to the secular schools and get a scientific education, but no character-building. So his idea was to try to provide some kind of educational program that would include all these elements."
Tolerance and dialogue being the two key words that dominate Gulen's discourse, students are taught to cultivate ties with and respect non-Muslim believers.
Gulen himself regularly meets with the leaders of Turkey's Christian and Jewish communities to help promote interconfessional links and Pope John Paul received him in Rome a few years ago. The Journalists and Writers Foundation, one of Gulen's public-relations tools, regularly sponsors seminars on interfaith dialogue.
Still, some experts question the scope of Gulen's tolerance, which excludes Communist atheists, Iran's Shi'ite clerics, and some of Turkey's minority groups.
Hakan Yavuz teaches political sciences at the University of Utah and is a leading scholar of the Gulen community. He says Gulen's state-oriented, nationalist views have set limits to his tolerance.
"When [Gulen] says 'tolerance,' one wonders what the boundaries of this tolerance are. Is there tolerance for [Turkey's crypto-Shi'ite] Alevis? Is there tolerance for Kurdish rights? Is there tolerance for gays and lesbians? What are the boundaries of this tolerance? When religion closely allies itself with nationalism, unfortunately, [it] does not become softer as far as individual rights are concerned."
Despite Gulen's ties with leading secular politicians -- such as late president Ozal or former Prime Ministers Tansu Ciller and Bulent Ecevit -- many in Turkey's civilian and military establishments view him with suspicion and believe his ultimate goal is to pave the way for an Islamic regime run by the Shari'a.
Others say these fears are unfounded, arguing that the Gulen community is a nonpolitical movement that only seeks to reconcile faith with secular institutions.
While insisting the group has nothing in common with what is known in Turkey as "political Islam," Yavuz dismisses claims that it has no political agenda: "I would not call [it] a nonpolitical movement, because I think it has a political objective, [which] is to create a new generation and transform society. And when you transform society, you also expect that society is going to transform the state. From my perspective, in terms of controlling the human mind, controlling society, and trying to get your [own] people in high government positions, it is a political project. But it is not a political project the way in which you might define some radical Islamic organizations [in Turkey]. It is not a political [form of] Islam. It does not want to work through parties. It wants to work through media, education, and societal networks to achieve its goal of Islamization of society. The goal is Islamization of society, but the means are different."
Turkish scholars Bulent Aras and Omer Caha have described Gulen's goals as being, among others, to "Islamize the Turkish nationalist ideology."
In Yavuz's view, the Gulen movement is comparable to the Catholic Opus Dei (Work of God) organization that appeared under Spanish dictator Francisco Franco.
Pretty much like Gulen's followers, Opus Dei members take a vow to dedicate their professional talents to the service of God and encourage a strong sense of elitism.
Like the conservative Spanish group, Gulen's group is surrounded by secrecy and is suspected of seeking to influence Turkey's polity by networking with decision-makers.
Finally, another feature the community shares with Opus Dei is that, although it initially emerged as a purely national movement, it has developed a strong missionary activity that gained it numerous sympathizers across the world.