The Motu proprio Magnum principium, promulgated by Pope Francis on 3rd September 2017, marks an important step even for scientific study of the liturgy and the application of that study in translating new liturgical texts. The papal document takes a step backwards in order to move forward more swiftly. The thinking of the Holy Father is clearly one of returning to the magnum principium of Sacrosanctum concilium, that the people might enter into the mystery celebrated through translations in modern languages and thus by understanding the texts, as indeed n. 21 of the liturgical constitution underlines. What might be considered even more interesting in Pope Francis’s motu proprio is the desire to return to the second principle according to which «it is for the competent territorial ecclesiastical authority mentioned in Art. 22, 2, to decide whether, and to what extent, the vernacular language is to be used; their decrees are to be approved, that is, confirmed, by the Apostolic See (probatis seu confirmatis) […]. Translations from the Latin text into the mother tongue intended for use in the liturgy must be approved (approbari debet) by the competent territorial ecclesiastical authority mentioned above» (Sacrosanctum concilium 36). 16 years after the promulgation of Liturgiam authenticam, the Motu proprio Magnum principium is intended to be more faithful to the letter of both Sacrosanctum concilium and Comme le prévoit, placing itself at a distance from the fifth instruction, providing general rules rather than a binding framework (and to be understood anew, according to the pontiff’s letter to Cardinal Sarah, Prefect of the Congregation for Divine Worship and the Discipline of the Sacraments). It is already evident from the title and from what is affirmed in the Motu proprio: «The great principle, established by the Second Vatican Ecumenical Council, according to which liturgical prayer be accommodated to the comprehension of the people so that it might be understood, required the weighty task of introducing the vernacular language into the liturgy and of preparing and approving the versions of the liturgical books, a charge that was entrusted to the Bishops». Wishing thereby to clarify and modify canon 838 of the Code of Canon Law regarding the translation of liturgical texts, Pope Francis established: «in the future can. 838 will read as follows: Can. 838 – §1. The ordering and guidance of the sacred liturgy depends solely upon the authority of the Church, namely, that of the Apostolic See and, as provided by law, that of the diocesan Bishop. §2. It is for the Apostolic See to order the sacred liturgy of the universal Church, publish liturgical books, recognise adaptations approved by the Episcopal Conference according to the norm of law, and exercise vigilance that liturgical regulations are observed faithfully everywhere. §3. It pertains to the Episcopal Conferences to faithfully prepare versions of the liturgical books in vernacular languages, suitably accommodated within defined limits, and to approve and publish the liturgical books for the regions for which they are responsible after the confirmation of the Apostolic See. §4. Within the limits of his competence, it belongs to the diocesan Bishop to lay down in the Church entrusted to his care, liturgical regulations which are binding on all». Pope Francis has established that the preparation of translations falls under the authority of the Conferences of Bishops, while granting the confirmatio, and no longer a recognitio, is the responsibility of the Holy See. Replying to a letter from Cardinal Sarah addressed to the Holy Father, the latter clarified what was intended by the words recognitio and confirmatio: «It is necessary to stress first the importance of the clear difference that the new MP establishes between recognitio and confirmatio, well established in paragraphs 2 and 3 of canon 838, to repeal the practice, adopted by the Dicastery following Liturgiam authenticam (LA), and that the new Motu Proprio wished to modify. Consequently, one cannot say that recognitio and confirmatio are “closely synonyms (or) interchangeable,” or that they “are interchangeable at the level of the Holy See’s responsibility”. […] In regard to the responsibility of Episcopal Conferences to translate “fideliter”, it is necessary to specify that the judgment on fidelity to the Latin, and the eventual necessary corrections, is carried out by the Dicastery, while today the norm grants the Episcopal Conferences the faculty to judge the goodness and the coherence of one and other terms in the translations of the original, when also in dialogue with the Holy See. Therefore, the confirmatione implies a more detailed examination word by word, […] the confirmatio takes into account the integrity of the book, namely, that it verify that all the parts that make up the typical edition were translated […]. In this connection, the recognition indicates only the verification and safeguarding of the conformity to the law and to the communion of the Church». With this Motu proprio, the Church has taken a healthy step back, turning to the mens of the Second Vatican Council, in order to move ahead more speedily. Liturgical science, in rethinking the translation of texts according to new norms, is called to make greater efforts. Translation “faithful to the letter” is no longer sufficient, but a kind of faithfulness to man is also required, a faithfulness to his capacity for understanding the mystery celebrated in his culture. In one word: the Motu proprio has relaunched with greater vigour the theme of liturgical inculturation, more than the responsibility of the bishops in the matter and in forming experts capable of translating liturgical texts, always seeking a learned balance between sana traditio and legitima progressio.