Pope Francis, in his foreword, states that one of the major themes in the thought of Joseph Ratzinger is the relationship between faith and politics: "His firsthand experience of Nazi totalitarianism led him even as a young student to reflect on the limits of obedience to the state for the sake of the liberty of obeying God." In support of this, he quotes from one of Ratzinger's texts presented in this volume: "The state is not the whole of human existence and does not encompass all human hope." Ratzinger explored various aspects of this subject in books, speeches, and homilies throughout his career, from his years as a theology professor to his tenure as Prefect of the Congregation for the Doctrine of the Faith and most recently as Pope Benedict XVI. This is the only book that collates all of his most significant works on political themes inside one volume.