The Church, like no other institution of its size, is beholden to its past. That past is, however, often misunderstood. As scholars and citizens, therefore, we lack a solid understanding of what sorts of tools the Church employs to engage with the modern world, and where they come from. Catholic Modern: The Challenge of Totalitarianism and the Remaking of the Church offers a new account of how the Catholic Church evolved over the course of the twentieth century, and in turn offers a new understanding of the dilemmas faced by the Church today. The question asked by the book is a simple one: when, why, and how did the Catholic Church become modern?  Building on discussions in The Immanent Frame and elsewhere, I suggest that, when it comes to religious institutions, “modern” can have an analytically precise meaning. It should not be equated with liberal, tolerant, progressive, atheist, or democratic. Modernity is, very often, none of those things. “Modern” can refer, instead, to what readers of TIF might call the “secular condition”: one in which religion is safely sequestered into something called the “private sphere.”