The course will provide the essential elements of Trinitarian doctrine. It will begin with the data offered by Sacred Revelation. This will be followed by an analysis of its maturation in the Tradition of the Fathers, up to the formulation of the dogma in the early Councils. It will conclude with a systematic reflection on one of the fundamental Mysteries of the Christian faith, the One and Triune God, in itself and in its action (the economy of salvation).