Freedom is vital both to Karl Barth's theology and to modern religion, politics, and culture. Leigh describes how Barth's lifelong fascination by freedom culminated in a fresh, daring engagement with it in his last completed book, volume IV/3 of the massive Church Dogmatics–which is probably the most important work of Christian theology in the twentieth century. That volume builds on Barth's earlier work but also goes beyond it in ways that have not yet been appreciated. Leigh...