"In order that the full and living Gospel might always be preserved in the Church the apostles left bishops as their successors. They gave them "their own position of teaching authority." -Second Vatican Council.
"The Tradition that comes from the apostles makes progress in the Church, with the help of the Holy Spirit. There is a growth in insight into the realities and words that are being passed on." - Second Vatican Council.
"The value of the Fathers and Writers is this: that in the aggregate they demonstrate what the Church did and does not yet believe and teach. In the aggregate they provide a witness to the content of Tradition, that Tradition which itself is a vehicle for revelation." -The Faith of the Early Fathers.
"It (Tradition) comes through the contemplation and study of believers who ponder these things in their hearts. It comes from the intimate sense of spiritual realities which they experience." - Second Vatican Council.
So Mary's Assumption lay dormant for centuries, until it somehow springs to life in modern times through pious and infallible contemplation?
Thinking about it, a couple of common sense ways occur to me to get a general idea of how old the actual concept of the Assumption is as opposed to when it was more recently infallible proclaimed.
1. Were there ancient churches/towns/places claiming to have the relics of Mary? Given how many places claimed to have relics of the true cross you would also think that there would be people claiming to have the relics of Mary unless it was generally thought by the people that there were no relics to have.
2. What does the Eastern Orthodox Church think and teach about the Assumption of Mary? The idea being that they are not likely to believe in something that is a recent invention.
So Mary's Assumption lay dormant for centuries, until it somehow springs to life in modern times through pious and infallible contemplation?
May I say, "ARRRRGGGGHHHHH!
Thank you. I feel better.
I say again: Councils, since the council of Jerusalem, are called to deal with problems. Their statements address problems which have arisen and reached a point where some resolution is considered necessary. They, and most papal declarations or definitions are essentially occasional -- that is, responding to situations.
The Church does not tend to write list of stuff, like the Westminster Confession or the Articles of Religion, that you hafta gotta believe without some prompting.
There is at least one flat contradiction in the catechism. (I can't remember exactly what it is.) ONLY if somebody starts a movement based on the contradiction will "the Vatican" rear back and resolve it. Actually they will rear back and appoint a committee which sometime later will make a recommendation which will be sent back for a re-write, which will be provisionally approved and then forgotten and then somebody will say, "Hey, what about that thing, you know, the one about the contradiction?" and something will be decided.
The Dominicans took something like 23 years to get from the proposed new "rule" for the Dominican Laity (folks like your humble servant -- okay, arrogant servant) to the version which reached my hands a few months ago.
When we say treasure in earthen vessels, we KNOW what we're talking about.
So, the idea that Mary was assumed body and soul into heaven (before or after she died is not decided) has been around for more than 1500 years (I am told. I don't research this stuff.) There's a story of some king who converted and asked for a relic of Mary, and there was some foot shuffling and whatnot and they told him, "Uh, Well, um, Your Majesty, y'see, we ain't got none, uh, cause, we don't have the body ...." I don't know if it's true, but that's the story.
Now before I go further I ought to point out that what we're saying about Mary is that she "now" enjoys what all the blessed "will" enjoy at the end of the age when soul is reunited to body for eternal bliss (in her case) or for the other thing. It is an essentially eschatologically related notion.
ANYWay, nobody cared enough about it to make it a de Fide thing. I couldn't say if most people believed it or not. But it seems that from http://www.freerepublic.com/perl/post#helpthe time of the definition of the Immaculate Conception there was increasing popular pressure for a definition of the Assumption. So finally the Pope got on the case.
And that meant asking for opinions from all over the Catholic world and running the matter by hordes of theologians. An encyclical, Deiparae Virginis Mariae, was sent out asking for the bishops to give their opinions. All this material was prayerfully considered and examined, and re-considered and re-examined.
Then when it had been talked to death and looked at from every possible angle, the Pope reared back and wrote MUNIFICENTISSIMUS DEUS which you can read. I recommend it if you're having trouble falling asleep. Here's the defining section:
Much of the material before this section, indeed most of the Encylical, reviews the procedures and the arguments and scholarship leading to the definition.44. For which reason, after we have poured forth prayers of supplication again and again to God, and have invoked the light of the Spirit of Truth, for the glory of Almighty God who has lavished his special affection upon the Virgin Mary, for the honor of her Son, the immortal King of the Ages and the Victor over sin and death, for the increase of the glory of that same august Mother, and for the joy and exultation of the entire Church; by the authority of our Lord Jesus Christ, of the Blessed Apostles Peter and Paul, and by our own authority, we pronounce, declare, and define it to be a divinely revealed dogma:
that the Immaculate Mother of God, the ever Virgin Mary, having completed the course of her earthly life, was assumed body and soul into heavenly glory.
So it wasn't a matter of it's lying dormant at all. It was a matter of the Church, in a way from the bottom up, stirring things up in a desire to end such debate as there might have been.
I hope this is clear about the process and about how we think (or, at least, how Pius XII thought) about the exercise of "infallibility."