As previously noted, Porphyry (c. 300 A.D.) was a non-Jew, a neo-Platonist philosopher,
who decided to write fifteen volumes against Christianity,
called lamely, "Against the Christians".
Up until this point, no one had seriously doubted the historicity of Daniel.
Christian apologists defended Daniel and shredded Porphyry's arguments and claims,
for the next two centuries, and by about 500 A.D. things were back to normal.
A comprehensive response to Porphyry was made by Jerome (c. 400 A.D.)
in his Commentary on Daniel, who quoted him several times.
There was no serious subsequent challenge over the book of Daniel until 1771:
Beginning in 1771, influenced by the Enlightenment, academics began to revive the old Maccabean date theory about the Book of Daniel. They all agreed that every accurate prediction in Daniel was written after the events took place.
- David Guzik Commentary on the Bible
Thus for nearly 1,400 years, neither Christians, nor Jews, nor critics
had challenged the basic authenticity and dating of the Book of Daniel.
It should be noted that even during the most heated
and violent disputes between Christians and Jews (i.e., over the question of Jesus as Messiah),
Jewish opponents did not discredit the book of Daniel itself
in order to dispute with Christians, but rather rejected the interpretation
of Daniel on a couple of points.
If identifying the book of Daniel as a 'pseudonomous late forgery'
had been an option for Jews, they as experts on their own national literature
would have been in the best position to make this claim.
However, right up until at least 300 A.D., both Christians and Jews
openly accepted the book of Daniel as authentic and Canonical,
and the book of Daniel remains in the Jewish (Hebrew) Canon to this day.
The Hebrew Canon has not been changed or reopened to debate since 90 A.D.,
and this is true for pretty much all denominations and sects of Judaism.
The Canon is believed to have been permanently closed before the Greek period (c. 331 B.C.)
The Jews unilaterally had rejected all manor and types of books which were written
in the Maccabean period, including those accepted by early Jewish Christians
who used the ancient Greek translations of the O.T.
This alone makes the theory that a Jew forged the book of Daniel
as late as 167 B.C. and somehow got it accepted into the Hebrew Canon
one of the most implausible ideas in the history of (German) Biblical criticism. *
These observations did not however, stop 18th and 19th century critics from
re-opening the case and reviving Porphyry's claims about the book of Daniel.
They chose to continue building on this edifice of sand,
because the rejection of tradition, and the rise of skepticism and materialism was simply too attractive to abandon.
Porphyry's original arguments had obvious weaknesses,
so 'modern' critics from 'the Enlightenment' attempted to repair, modify,
and bolster the theory with many more supplemental arguments.
These viewpoints became popular in the 19th century,
and took over the universities of Europe and the USA.
As a result, many commentaries on the book of Daniel
began to be published which covertly or openly took the position
that the book of Daniel was a late forgery, and useless as an
example of Biblical prophecy for the Christian Messiah.
Naturally, conservative Christian scholars who held the traditional view
of the authenticity of Daniel got little useful help from Jewish scholarship
on either the integrity or the interpretation of Daniel.
The Jewish intellectual world was an entity which remained largely to itself.
* the question arises, what are some even more implausible theories
spawned by 19th century critics?
A great example is the paranoid Conspiracy Theory that
'the Massoretic Jewish copyists had tampered extensively with the Hebrew Text.'
Up until 1960 the oldest copy of the Hebrew Bible was from the Middle Ages,
and it was easy to claim that a lot could have happened between
the time of Jesus and the 19th century.
However, in the late 1950s the Dead Sea Scrolls were discovered:
10 or 11 caves full of scrolls dating from about 200 B.C. to 100 A.D.
Manuscripts and fragments were found of just about every book in the Bible,
and two whole copies of Isaiah showed that the text hadn't changed significantly
during copying for at least 1,500 years, from the time of Jesus
until the invention of the printing press.
All the exaggerated speculations about Hebrew Bible tampering
had to be quietly abandoned by sensible scholars.
Nobody in academia however apologized,
for having slandered Jewish copyists for centuries.