This book probes the meaning and history of the open-hearted Christian commitment we call ecumenism. Ranging across a century of active Christian engagement, historical theologian Keith Clements finds in the ecumenical movement a radical openness that has served to enliven, sustain, and renew Christianity through tumultuous times. Indeed, in the itch to encounter and learn from others very different from ourselves, to "live in more than one place at once," Clements identifies a core element in ecumenical Christian spirituality that is perhaps more relevant today than ever before.