Might be worth reading. http://www.christiantruth.com/articles/assumption.html
http://triablogue.blogspot.com/2006/09/assumption-of-mary-in-later-sources.html
Also, noted RCA Karl Keating stated:
Still, fundamentalists ask, where is the proof from Scripture? Strictly, there is none. It was the Catholic Church that was commissioned by Christ to teach all nations and to teach them infallibly. The mere fact that the Church teaches the doctrine of the Assumption as definitely true is a guarantee that it is true. Karl Keating, Catholicism and Fundamentalism (San Francisco: Ignatius, 1988), p. 275.
Which being interpreted means, truth it is not dependent upon the weight of Scripture, but rests upon the self-proclaimed assured infallibly of Rome, by which she proclaims she is infallible. Rome says is it true, and therefore it is, and no weight of evidence can possible impugn that. The original firewall.
The ultimate reason an RC will invoke Scripture or Tradition as authoritative is not because that is how you conclusively ascertain Truth, but it is in order to have you make a fallible decision to implicitly submit to what Rome decrees is Truth, as she has decreed that she possesses assured formulaic infallibility, largely based on her claim of formal decent, and thus only by faith that she is can one really have assurance of doctrine.
Upon this premise of established authority, rather than the church being established by supernatural means, by conflation with Scripture and its means of establishing truth - and being in rebellion against the interpretation of those who sat in the seat of authority - then they would have had to submit to those who sat in Moses seat.
The circular logic of Catholics is absolutely stunning.