Sacred Heart of Jesus
When Pius XII wrote the encyclical Haurietis aquas (15 May 1956), the devotional form though certainly still strong was nonetheless in crisis. Moves towards liturgical reform sought an extreme sobriety in expression, together with a theological mindset that sought to steer entirely by Scripture and the Fathers. Pius XII sought to display the enduring significance of Sacred Heart devotion, deeply linked as he saw it to the central mystery of Christ. Joseph Ratzinger would later point out that the questions addressed in Haurietis aquas were presupposed, rather than superseded, in the liturgical reform of Vatican II.
Pius XII begins with the prophetic words of Isaiah 12:3, of which Jesus proclaims himself the fulfilment in his Easter mystery in John 7:37–39. This, he writes, comes naturally to mind when recalling the reasons for the institution of this feast throughout the Church by Pius IX. Haurietis aquas seeks to prove that Sacred Heart devotion is not invented by Margaret Mary Alacoque; rather, the revelation she received yields nothing new. It was because the private revelation received by her was so in keeping with theological tradition that the devotion revealed to her was promulgated. Pius XII writes: “the devotion […] to the love of God and to Jesus Christ for the human race by means of the revered symbol of the pierced heart of the crucified redeemer has never been altogether unknown to the piety of the faithful, although it has become more clearly known […] in quite recent times.” Thus, devotion to the Sacred Heart is deeply rooted in Scripture and patristic theology, a worship of the love with which God, through Jesus, loved us, and at the same time, an exercise of our love by which we are related to God and to other people.
The essence of this devotion is a veneration of the person of Jesus Christ from the perspective of his divine and human love. This love was revealed through his sacred humanity, and is symbolised by his wounded physical heart. In the words of Pius XII: “When we adore the Sacred Heart of Jesus Christ, we adore in it and through it both the uncreated love of the divine Word and His human love , […] because both loves moved our Redeemer to sacrifice Himself for us and for the whole Church, his spouse.”