The primary aim of this book is to reconsider the meaning of darkness within mystical and contemplative thought and practice--especially as the ground and source of love. The book examines how a sustained, critical attention to apophatic spiritual traditions can help us respond to the gaps, silences, and empty places that have become such a prominent feature of contemporary experience. Contemplative practice rooted in unknowing reflects a deep respect for the unsayable, but also comes to expression in a rich and varied poetry of darkness that limns loss and absence with great delicacy, grace and courage. This book considers how critical retrieval of this poetry--especially that arising from ancient Christian traditions of the via negativa--can help us engage and respond to our own experiences of loss and absence. It argues that our experience of contemplative spiritual practice can be revitalized by attending more carefully to the darkness that so often surrounds and courses through it, not only as part of personal practice but also as part of the shared work of recovering and deepening what the Christian mystical tradition often refers to simply as "the common life." Or what the thirteenth-century Flemish mystic Hadewijch of Antwerp calls "the insurmountable darkness of love."