2. THE TEACHING OF THE CHURCH ON THE TRINITY

The Catholic doctrine on the Trinity is expressed in the various creeds and definitions, such as the Apostles' Creed, the Athanasian Creed, the Nicene Creed, and many others of later date, and in Denzinger.[40] Finally, the Catholic belief in the Trinity was summed up by the Fourth Lateran Council (1215) in that famous chapter, "Firmiter": "Firmly we believe and simply we confess that one alone is true God, the Father, the Son, the Holy Spirit, three persons, but one essence, one substance, and one nature entirely simple. The Father is from no one, the Son from the Father alone, and the Holy Ghost equally from both... consubstantial, co-equal, co-omnipotent, and co-eternal... . We confess and believe with Peter Lombard that it is one supreme being, incomprehensible and ineffable; this supreme being is truly the Father and the Son and the Holy Ghost, three persons together and each one singly; and therefore in God there is only a Trinity, not a quaternity, because each of the three persons is that thing, that substance, that essence, that divine nature."[41]

Again, "No real distinction exists between the essence and the persons, but a real distinction exists between the persons among themselves."[42]

Again, the three persons are one principle of operation without, because the divine operation without proceeds from the divine omnipotence, which is common to the three divine persons.[43]

This definition of the Fourth Lateran Council was amplified by the Council of Florence (1439) in the dogmatic decree of the union of the Greeks: "We define that the Holy Spirit is eternally from the Father and the Son and that He has His essence and His subsisting being simultaneously from the Father and the Son, and that He proceeds eternally from both as from one principle and by one spiration."[44] Other definitions about each person in particular may be found here.

The mystery of the Trinity may be more briefly stated as the mystery of one God in three divine persons. But in opposition to the pseudo-synod of Pistoia it should be said that it is not one God divided into three persons but one God in three distinct persons, since there is no real distinction in the Godhead Himself, as the Eleventh Council of Toledo declared: "The Godhead is not reduced to single persons and is not increased into three persons."[45]