I will not describe Cardinal Gerhard Müller, formerly prefect of the Congregation for the Doctrine of the Faith, as a “conservative” cardinal as it would be both offensive to him and play into the hands of those determined to politicise the faith. He is simply a fine, authoritative Catholic pastor and teacher, deeply conscious of his God-appointed role in leading lay people to understand their Catholic faith more clearly – especially in these times of grave confusion in the Church. While The Power of Truth: The Challenges to Catholic Doctrine and Morals Today (Ignatius Press, 190pp, £14.99/$17.95) is largely a collection of Müller’s essays from the US magazine First Things, the book also contains his “Manifesto of Faith”, an essay on the indissolubility of marriage from L’Osservatore Romano and a long reflection on Humanae Vitae – always a touchstone of orthodoxy within the hierarchy. It is clear from reading this heartening collection that Cardinal Müller’s own guiding principle is the Gospel text (said to be the favourite of St John Paul II): “You shall know the truth and the truth will set you free.” Thus the Creed is “not about the state of our emotions, nor about what Jesus subjectively means to us” – nor, in an implicit rebuke to Cardinal Blase Cupich of Chicago’s oft-quoted remark, is there any such thing as “paradigm shifts” in Church teaching.