The Vatican Council's Condemnation of the Evolution of Dogmas:
From the Vatican Council's Dei Filius, Ch. 4:
13. For the doctrine of the faith which God has revealed is put forward not as some philosophical discovery capable of being perfected by human intelligence, but as a divine deposit committed to the spouse of Christ to be faithfully protected and infallibly promulgated.
14. Hence, too, that meaning of the sacred dogmas is ever to be maintained which has once been declared by Holy mother Church, and there must never be any abandonment of this sense under the pretext or in the name of a more profound understanding.
May understanding, knowledge and wisdom increase as ages and centuries roll along, and greatly and vigorously flourish, in each and all, in the individual and the whole Church: but this only in its own proper kind, that is to say, in the same doctrine, the same sense, and the same understanding [n. 36: St. Vincent of Lerins, Commonitorium (Notebook), 28 (PL 50, 668)].