In the fall of 1964, Trappist monk Thomas Merton prepared to host an unprecedented gathering of peace activists. "About all we have is a great need for roots," he observed, "but to know this is already something." His remark anticipated their agenda--a search for spiritual roots to nurture sound motives for "protest." This event's originality lay in the varied religious commitments present. Convened in an era of well-kept faith boundaries, members of Catholic (lay and clergy), mainline Protestant, historic peace church, and Unitarian traditions participated. Ages also varied, ranging from...