For most of the last twenty years, sociologists have studied the "decline" of religion in the modern world--a decline they saw as a defining feature of modernity, which promotes materialism over spirituality. The revival and political strength of varying religious traditions around the world, however, has forced sociologists to reconsider.

This paradox has led Hervieu-Léger to undertake a sociological redefinition and reexamination of religion. For religion to endure in the modern world, she finds, it must have deep roots in traditions and times in which it was not defined as irrelevant. This reasoning leads her to develop the concept of a "chain of memory"--a process by which individual believers become members of a community that links past, present, and future members. Thus, like cultural tradition, religion may be understood as a shared understanding with a collective memory that enables it to draw upon the deep well of its past for nourishment in the increasingly secular present.

Hervieu-Legér also argues that the modern secular societies of the West have not, as is commonly assumed, outgrown or found secular substitutes for religious traditions; nor are they more "rational" than past societies. Rather, modern societies have become "amnesiacs," no longer able to maintain the chain of memory that binds them to their religious pasts. Ironically, however, even as the modern world is destroying and losing touch with its traditional religious bases, it is also creating the need for a spiritual life and is thus opening up a space that only religion can fill.