Daniel: The Canon
Critics argue against the canonicity of Daniel on two main grounds. The first is the claim that the Jews themselves did not accept Daniel as a prophetic book until long after the Old Testament canon was closed.
This argument fails to take into account the fact that although the present position of the book of Daniel in the Masoretic compilation of the Henrew Scriptures is among the 'Writings' (not the 'Prophets'), this was not the original position of the book of Daniel within the Hebrew canon. Critics who use this argument assume that since Daniel is placed among the 'Writings' of the Masoretic compilation, it has always been there.
In doing so they display ignorance of the fact that the earlier placement of Daniel was in fact placed within the other books of prophecy as early as the LXX. In addition, it was included in the prophetic canon of the early Qumran community (from at least 100 BC onwards), and Josephus makes explicit reference to the book of Daniel as one of the prophetic works, proving that it was already recognised as such well before the 1st century. The very fact that Daniel is referred to by the gospels as within the prophetic canon, is evidence that it was recognised as such.
The shift made by the Masoretes (for reasons best known to themselves), did not come until about 700 years later, rendering this objection completely irrelevant.
David Conklin's excellent article on Daniel comments (with emphasis added):
The "earliest literary evidence of Daniel's inclusion among the Ketubim is to be placed somewhere between the fifth and eighth centuries A.D. ... This leads to the conclusion that at some point in time the rabbis transferred the book from the prophetic corpus to the last third of their collection of Holy Scripture.
That probably happened long before the fifth century. Audet may be right in looking to the second century [to be more accurate the only evidence he could provide is from the "end of the second century"--"the famous Baraitha attributed by the Talmud to R. Juda the Patriarch"] as an appropriate date." [Koch, 123; Audet, 145]
As Archer has very well noted: "the Masoretic division of the canon, coming as it did six or seven centuries after Flavius Josephus [who did include Daniel among the prophets], has no bearing whatever on the date of Daniel's composition or on its status as a truly prophetic work."
David Conklin, 'Evidences Relating to the Date of the Book of Daniel', 2004
The second objection rests on a even less substantial argument. It is claimed that the absence of Daniel from the list of notable men given by Joshua Ben Sirach (around 170 BC), together with the fact that Ben Sirach quotes all the other Old Testament prophets except for Daniel, is evidence that he was either unaware of the book (suggesting it had not been written), or that he did not recognise it as canonical (suggesting it was not recognised by the Jews as a legitimate work).
This is an argument from silence, as Conklin notes (emphasis added):
Another point that is sometimes brought out is that Daniel was not listed in the Wisdom of Sirach, otherwise known as Ecclesiasticus, (44:1ff) which was written by Ben Sira "near the start of the 2d century B.C.". [Burtchaell, 482; Heuvel, 3; Harrison, ISBE. (1979): 864, (1969): 1123-4; Dummelow, 529-30; Hammer, 5; Eissfeldt, 521; Fox, 335 puts the date at 190 B.C. to 180 B. C.; likewise Lacocque (1979): 7; Larue, 395; Di Lella (1987): 10; and Taylor [2], [4]; Barnes, 43 notes that this argument was also made by De Wette, Bleek, Eichorn, Kirms, and Bretschneider] Burtchaell claims that this work is a "catalog of famous Hebrew ancients."
What he neglects to tell the reader is that this work also does not mention Joseph, Ezra, Mordecai, Asa, Jehoshaphat, Esther, all of the Judges except Samuel, and other "famous Hebrew ancients."
It therefore seems that Ben Sira was not attempting to "catalog" all of the famous personages from the past. [contra Lacocque, 7] What criteria was used by this writer for determining who would be included in his list and who would not make the cut is not given. Harrison notes that the sheer "popularity of Daniel at Qumran" demonstrates "the shallowness of this objection." [Harrison, ISBE. (1979): 864, (1969): 1123]
David Conklin, 'Evidences Relating to the Date of the Book of Daniel', 2004
A final quote from Conklin is relevant here:
Recent studies indicate that the canon was closed in Maccabean times and not at the end of the 1st century A.D. [See S. Z. Leiman, The Canonization of the Hebrew Scripture. (Archon, 1976); cited by Wenham, 51 and Baldwin (1978a): 72; Barnes, 48 states, emphasis mine, that the canon was closed "long before the time of the Maccabees".]
This would not allow time for Daniel to have been accepted as part of the canon if it was written as late as is commonly assumed. Harrison states: "It is now clear from the Qumran MSS that no part of the canonical literature was composed later than the 4th century B.C.." [Harrison, ISBE. (1979): 862]
This means that if Daniel was composed shortly before the canon was fixed then it would have been quite unusual for it to have been accepted as canonical--especially when everybody would have realized its novelty. The fact that Daniel was, and is, accepted into the canon indicates that it was written quite some time before the canon was considered closed.
David Conklin, 'Evidences Relating to the Date of the Book of Daniel', 2004