Although he is not always recognized as such, Soren Kierkegaard has been an important ally for Catholic theologians in the early twentieth century. Moreover, understanding this relationship and its origins offers valuable resources and insights to contemporary Catholic theology. Of course, there are some negative preconceptions to overcome. Historically, some Catholic readers have been suspicious of Kierkegaard, viewing him as an irrational Protestant irreconcilably at odds with Catholic thought. Nevertheless, the favorable mention of Kierkegaard in John Paul II's Fides et Ratio is...