Dekert's book is important for anyone interested in the solid reasoning behind Benedict XVI's document reviving the older form of Catholic liturgy. While these are familiar facts, what is innovative about Dekert's work is that it brings together in one place the diverse and scattered views and arguments of those opposed to the liturgical reform introduced in the Catholic Church by Pope Benedict XVI in 2007. It is important to see these diverse ideas, presented not only in books but often in fleeting writings and polemics, synthetically connected. Yet the motu proprio Summorum Pontificum was constantly under fire from hostile church intellectuals and even some high-ranking clergy. Thanks to Dekert's work, we can see and evaluate the intellectual coherence—or lack thereof—of these arguments not only in the context of Catholic tradition but also in their internal sense. Importantly, Pope Francis's motu proprio Traditionis custodes, intended to annihilate the German pope's liturgical reform, was also subjected to a coherence test. It is no surprise that Pope Francis's text failed this test, but it's thanks to Dekert's book that we can clearly understand why. Dekert provides all the necessary context so that every reader can understand why the liturgical war in the Catholic Church has flared up with such force in recent years. It's undoubtedly a must-read.