The teaching of the Council of Florence, reiterated in the catechism, is that the Spirit "proceeds eternally from both as from one principle and one spiration." Florence continues: "We declare that when Holy Doctors and Fathers say that the Holy Spirit proceeds from the Father through the Son, this bears the sense that thereby also the Son should be signified, according to the Greeks indeed as cause, and according to the Latins as principle of the subsistence of the Holy Spirit, just like the Father."
But, as you say, the catechesis in the RCC is not the best, and it's possibly you were taught something other than the Vatican's dogmatic teaching.
Iconodule you are correct, and the inconsistency between the processional theory proposed at the Council of Florence and the teaching of St. Maximos becomes all the more apparent when the Greek theological terms found in the two texts are compared. Below are the two excerpted texts (i.e., Maximos' Letter to Marinus
and the Decree of Florence
) with the technical Greek terms in brackets:
"From this they [i.e., the Romans] showed that they themselves do not make the Son the cause [αἰτίαν] of the Spirit for they know that the Father is the one cause [αἰτίαν] of the Son and the Spirit
, the one by begetting [γέννησιν] and the other by procession [ἐκπόρευσιν], but they show the progression [προϊέναι] through Him [i.e., the Son] and thus the unity of the essence [οὐσίας]." (1)
"In the name of the Holy Trinity, Father, Son and Holy Spirit, we define, with the approval of this holy universal council of Florence, that the following truth of faith shall be believed and accepted by all Christians and thus shall all profess it: that the Holy Spirit is eternally from the Father and the Son, and has His essence [οὐσίαν] and His subsistent being [ύπαρχτιχόν είναι] from the Father together with the Son, and proceeds [ἐκπορεύεται] from both eternally as from one principle [μίᾶς άρχής] and a single spiration. We declare that when Holy Doctors and Fathers say that the Holy Spirit proceeds [ἐκπορεύεσθαι] from the Father through the Son, this bears the sense that thereby also the Son should be signified, according to the Greeks indeed as cause [αἰτίαν]
, and according to the Latins as principle [άρχήν] of the subsistence [ύπἁρξεως] of the Holy Spirit
, just like the Father." (2)
Clearly the theological position of the Latin Church at Florence had moved beyond what St. Maximos had said was acceptable in his Letter to Marinus
, and - in fact - it actually embraced what he explicitly condemned.Bibliography:
(1) A. Edward Siecienski, "The Filioque: History of a Doctrinal Controversy," (New York: Oxford University Press, 2010), pages 80-81.
(2) Norman P. Tanner, S.J., (Editor), "Decrees of the Ecumenical Councils," (London and Washington, D.C.: Sheed & Ward, and Georgetown University Press, 1990), pages 526-527.