Abstract

The article investigates the language of the faith of the Church on the mystery of God. It analyzes its origin and typology, its specificity and ecclesial meaning, its ecumenical relevance, its logical coherence and its theological actuality. It follows the definitions and declarations of the Magisterium while placing the doctrine within the bi-millennial history of Trinitarian theology. The study underlines the importance for the unity of the Church of the formulation of the faith which in adoring the inseparable Trinity proclaims the Holy Monarchy - origin of the divine life and of the sacramental economy - of the eternal, unbegotten Father, principle of the whole deity. After having followed the efforts made by the first apologists to sketch out the language of the ineffable mystery, and the various models of trinitarian language, the study exposes the language used by the councils in East and West: Nicea I and II, Constantinople I to III, Lateran I to IV, Lyons II to Florence, Vatican I to II, so as better to formulate the principles which articulate the rule of faith of the Church. The logic of the ecclesial language is resumed in propositions concerned with the main affirmations of faith and the proclamation of the mystery. The first propositions treat the knowability of the mystery, the possibility of its verification and the dialectic of its language. The main propositions refer to the three divine hypostases, Father, Son and Spirit, in the economy of salvation and in