From the Catechism
scborromeo.org/ccc/p1s1c2a2.htm#83
II. THE RELATIONSHIP BETWEEN TRADITION AND SACRED SCRIPTURE
One common source. . .
80 "Sacred Tradition and Sacred Scripture, then, are bound closely together, and communicate one with the other. For both of them, flowing out from the same divine well-spring, come together in some fashion to form one thing, and move towards the same goal."40 Each of them makes present and fruitful in the Church the mystery of Christ, who promised to remain with his own “always, to the close of the age”.41
. . . two distinct modes of transmission
81 "Sacred Scripture is the speech of God as it is put down in writing under the breath of the Holy Spirit."42
"And [Holy] Tradition transmits in its entirety the Word of God which has been entrusted to the apostles by Christ the Lord and the Holy Spirit. It transmits it to the successors of the apostles so that, enlightened by the Spirit of truth, they may faithfully preserve, expound and spread it abroad by their preaching."43
82 As a result the Church, to whom the transmission and interpretation of Revelation is entrusted, "does not derive her certainty about all revealed truths from the holy Scriptures alone. Both Scripture and Tradition must be accepted and honored with equal sentiments of devotion and reverence."44
But paragraph 80 strongly implies that Tradition is in an identity with Scripture, since all revelation from the divine wellspring flows forth to form “one thing” (the canon of Scripture). God’s primary intent in revelation was to reveal himself, not to found a Magisterium.*
But he found the Magisterium necessary because otherwise people would even wrest divine revelation unto death by their heretical interpretations. But the necessity of the Magisterium should never cause us to give it an ontological priority over the Word of God, either written (as the Magisterium is the interpreter of it, a minister of the word, not a magister of the word: only a magister to men), or incarnate (as the Church is the vicegerent of Christ, not Christ himself, although I’ve seen some Catholics take the “he who heareth you, heareth me” thing too far and establish at least a quasi-identity between the Church and Christ, and the Magisterium and the Sermon on the Mount**).
The Magisterium is not there to add to revelation: it has no authority to do so. It has precious little positive function. The vast majority of the magisterial function has been negative - not adding to revelation, or even telling men what revelation says, but only telling men who have erred precisely what revelation is
not. This may have changed a bit since the 19th century (with a spate of Popes that liked to proclaim new Marian dogmata and not content themselves with denouncing Marian heresy), and more since Vatican II, but the classical and traditional attitude and intention of the Magisterium, as well as its modern drift, is summed up well in the last two words of every canon of every ecumenical council until Vatican II:
anathema sit, “let him who holds this opinion be condemned”. The canons tended to stay very short in length as well. The first alteration from this pattern was the Tridentine
Decree on Justification, which had a lengthy essay (monograph) prescribing what exactly justification was and how it was to be spoken of “prefixed” to the half-a-dozen canons. The canons (the negative function, proscribing belief) were for the first time an after-thought to a “decree” (the positive function, prescribing belief).
It’s hard to exegete an English text. They need to write the Catechism in Greek the next time so the layman can be convinced it says whatever the occasion calls for.
*Although I hear the retort even now, that the “one thing” is the Church, the Petrine office, or the general Magisterium of it (the Church, not the Petrine office). This seems to be excluded by the context, given the way “the Church” is mentioned in the next sentence.
**This is not denying that the Church is the mystical body of Christ, or that Christ is the head of the Church. It’s just that a body (no matter how mystical) has no authority or ability to think on its own without its head (which containeth the brain, the reason, the word - the
logos!). It is to say that the Church does not and can not give forth new revelation on its own (which is a prerogative which, on my view, is ascribed to the Church by several views on the relation of Scripture and Tradition), but can only expound that revelation which it already has. If my analogy is too irreverent I beg forgiveness of thee and of God.