As a phenomenologist Lacoste is concerned with investigating the human aptitude for experience; as a theologian Lacoste is interested in humanity's potential for a relationship with the divine, what he terms the 'liturgical relationship'. Beginning from the proposition that prayer is a theme that occurs throughout Lacoste's writing, and using this proposition as a heuristic through which to view, interpret and critique his thought, this book examines Lacoste's place amid both the recent 'theological turn' in French thought and the post-war emergence of la nouvelle théologie. Drawing upon unpublished and out of print material previously only available in French, Romanian or German, the book will be of interest to scholars of philosophy, phenomenology and theology.