Unlike some modern Catholic apologists who see the Bodily Assumption in the Bible and the patristics (via fanciful eisegesis and a lot of wrenching patristic texts and scholarly literature out of context), Robet Sungenis displays much more intellectual honesty about the evidence for the Asusmption and the ultimate reason why one believes it to be a de fide dogma:
My inkling is that Dr. White was quite
anxious to debate the Assumption of Mary since he had been asking Catholic
apologists to do so but no one except me would take the challenge. It’s easy to
see why there was such reticence among Catholics. Here is a Catholic doctrine that
has no direct Scriptural support (only metaphorical allusions) and no early or
mid-patristic support, much less consensus. So, if the Catholic defending this
doctrine is going to be honest, he must concentrate his debate on a very late
patristic (if not early medieval testimony) to the Assumption of Mary; admit
that the belief in the doctrine more or less grew over time; and that the single
greatest reason we hold to it today is because the pope declared it to be a
dogma of the faith in 1950, which is rather late as far as dogma is concerned.
. . .
if one reads the 1950 document
Munificentissmus Deus one will find that Pius XII goes back deep into history
for testimony of the Assumption of Mary, beginning at least at the 7th century.
He then works his way up through the middle ages and shows that by the time we
get to the 20th century there is a huge groundswell of support for the
doctrine. . . . So what is Dr. White’s issue? Well, there are several. The
first is that he believes the patristic period ends with St. Augustine around
the beginning of the 5th century. But that is a purely arbitrary end point.
Catholics often extend the patristic period to include the 7th century. And if
so, there is definitive support for belief in the Assumption of Mary in John
Damascene, Germanus of Constantinople and Modestus of Jerusalem, not to mention
the sacramentary of Adrian I and the Gallican sacramentary. So, the whole thing
rests on how we define the patristic period. (Robert Sungenis, "Response
to James White's Comments on Our Debate Concerning Predestination/Fre Will and
the Assumption of Mary," November 29, 2010, pp. 1-2, copy in my
possession)