development of doctrine
Understanding by Catholic doctrine the deposit of faith, or the sum-total of truths supernaturally revealed to man, we may briefly sketch the Catholic view of this subject.
(1) While substantially contained in primitive revelation, the deposit of faith grew from the time of Adam until that of Christ and the Apostles.
New truths, hitherto entirely unknown, or understood but imperfectly, were revealed through the ancient prophets, but more especially through Jesus Christ, the only-begotten Son of the Father.
(2) Public revelation was completed with the Apostles, so that after the death of the last Apostle no new doctrine was revealed to the Church as such.
(3) Revelation as completed in the Apostles will always remain the same, in the sense that its meaning cannot be changed nor can its opposite become true.
It is on this proposition that the modernists suffered shipwreck.
They would abolish the old dogmas and substitute new ones, evolving them out of their subconsciousness or experience.
(4) The deposit of faith may and does develop extrinsically.
Thus, owing to the outbreak of a heresy, the Church may propose explicitly what was contained in a certain doctrine only implicitly; what was heretofore believed more or less confusedly may be stated clearly and distinctly; the theoretical principle underlying a certain practise may be brought out and defined; owing to special needs, certain doctrines may be preached with greater frequency and emphasis.
The right to proclaim such "new dogmas" is clearly contained in the nature of the magisterium of the Church.
Being a living magisterium, it has the right and the duty to teach.
It is the duty of a live teacher to explain his own teachings, to emphasize certain points, to settle doubts, to correct errors.
Hence the Church is not tied down to a repetition of ancient formulas (as the Greek schismatics imagine), nor can such new dogmas be rightly called corruptions of Christ's doctrine (as many Protestants consider them).
What Newman meant to say in his famous "" need not be urged beyond the limits assigned here.
New Catholic Dictionary