Armstrong, a former nun who became a writer and broadcaster and now teaches at the Leo Baeck College for the Study of Judaism and the Training of Rabbis and Teachers, has been prolific in producing books and television shows on various aspects of religious life.

In this her latest book, she tackles the difficult issue of the rise of fundamentalism. While we often think of fundamentalism as a late 20th Century Christian phenomenon, it is much more universal than that.

Armstrong traces fundamentalist movements among Jews, Muslims, and Christians, and throughout many time periods in history. American Protestants who coined the term in the early 20th Century seemed to mean that they wanted to get back to basics and the fundamentals of the Christian tradition, which they identified as a literal interpretation of the Bible and acceptance of certain core doctrines and beliefs. This definition is less useful when discussing Jewish and Islamic fundamentalism, but Armstrong says she has come to believe that the term is here to stay, even though it isn’t perfect. She notes the pattern that Martin Marty and R. Scott Appleby identified in all fundamentalist movements.

They are embattled forms of spirituality, which have emerged as a response to a perceived crisis. They are engaged in a conflict with enemies whose secularist policies and beliefs seem inimical to religion itself. Fundamentalists do not regard this battle as a conventional political struggle, but experience it as a cosmic war between the forces of good and evil. They fear annihilation, and try to fortify their beleaguered identity by means of a selective retrieval of certain doctrines and practices of the past. To avoid contamination, they often withdraw from mainstream society to create a counterculture; yet fundamentalists are not impractical dreamers. They have absorbed the pragmatic rationalism of modernity and, under the guidance of their charismatic leaders, they refine these "fundamentals" so as to create an ideology that provides the faithful with a plan of action. Eventually they fight back and attempt to resacralize an increasingly skeptical world.

Armstrong says one major contribution to the rise of fundamentalist movements in the three religions over the years has been a loss of understanding of the role of and differences between myth and rational thought. In pre-modern times, both were seen as essential ways to get to truth. Myth was thought to be primary. It was concerned with what was thought to be timeless and constant in our existence. Myth looked back to the origins of life, to the foundations of culture, and to the deepest levels of the human mind. It was concerned with meaning, not with practical matters.

Many Bible stories were written as myths to convey eternal truths, she says, and they suffer when they are read as rational, literal truth rather than mythic truth.

To help us understand what is happening now, Armstrong devotes nearly a third of her book to setting the world stage for Jews, Muslims, and Christians from 1492 to 1870, and then looks at fundamentalist movements in the three religions from 1870 to today.

Armstrong concludes that we can’t be religious in the same way as our ancestors in the pre–modern conservative world, when the myths and rituals of faith helped people to accept limitations that were essential to agrarian civilization. "We are now oriented to the future," she says, "and those of us who have been shaped by the rationalism of the modern world cannot easily understand the old forms of spirituality."

While she sees some fundamentalists today as making a mockery of both religion and science, she recognizes that the movements are not going to disappear and the liberal, secular establishment must work to build bridges to them rather than try to suppress and coerce them.

She suggests a good starting point is to remember that the theologies and ideologies of fundamentalism are rooted in fear. "The desire to define doctrines, erect barriers, establish borders, and segregate the faithful in a sacred enclave where the law is stringently observed springs from that terror of extinction which has made all fundamentalists, at one time or another, believe that the secularists were about to wipe them out. The modern world, which seems so exciting to a liberal, seems Godless, drained of meaning, and even satanic to a fundamentalist." It is impossible, Armstrong contends, to reason such fear away or attempt to eradicate it by coercive measures. A more imaginative response, she suggests, would be to "try to appreciate the depth of this neurosis, even if a liberal or secularist cannot share this dread–ridden perspective."