The living magisterium makes extensive use of documents of the past, but it does so while judging and interpreting, gladly finding in them its present thought, but likewise, when needful, distinguishing its present thought from what is traditional only in appearance.
“It is revealed truth always living in the mind of the Church, or, if it is preferred, the present thought of the Church in continuity with her traditional thought, which is for it the final criterion, according to which the living magisterium adopts as true or rejects as false the often obscure and confused formulas which occur in the monuments of the past.
“Thus are explained both her respect for the writings of the Fathers of the Church and her supreme independence towards those writings–she judges them more than she is judged by them.” — The Catholic Encyclopedia, 1912*
* Note: This does not mean the magisterial documents or expressions of present teaching cannot be tweaked or even corrected when necessary. It only indicates that such adjustments would also fall finally under the exclusive competence of the magisterium.