CCC 1557
© Libreria Editrice Vaticana Source: vatican.va
The Second Vatican Council "teaches . . . that the fullness of the sacrament of Holy Orders is conferred by episcopal consecration, that fullness namely which, both in the liturgical tradition of the Church and the language of the Fathers of the Church, is called the high priesthood, the acme (summa) of the sacred ministry." LG 21 # 2.
Read the full chapter 3. The Sacraments at the Service of Communion ¶1533–1666