Adversus Christianos, Latin for Against Christians, is a set of fifteen books written in Sicily by pagan philosopher Porphyrius (233 AD -c.303), considered the most able and most bitter adversary the early Christians ever knew. These books were burned in 448 under emperor Teodosius, after they were banned in the Council of Ephesus.
These books were soon refuted by Eusebius and Methodius, and latter by Apollinarius (in 345) and Philostorgius (in 425); but neither the books nor the four replics have survived. Based on Hortensius's biography of Porphyrius, it can be inferred that the purpose of these books was to prove that the Book of Daniel was not a prophetic text, but that it related events that happened to the kings of Syria and Egypt  and was written after the historical facts.
Porphyrius, in the twelfth book of Adversus Christianos, was the first to attack the authenticity of the Book of Daniel and his arguments have been repeated since that time by many scholars. The core of this attack is that Daniel's prophecies are exact to the minute details, so they are not prophecies at all, but they were written by some Pseudo-Daniel living during the time of these events. Daniel was written during the reign of Antiochus Epiphanes, in Greek, and that "Daniel did not so much predict future events as narrate past ones".
- Daniel was not composed by the person to whom it is ascribed in its title, but rather by some individual living in Judaea at the time of Antiochus Epiphanes.
- Daniel did not foretell the future so much as he related the past.
- Whatever he spoke of up till the time of Antiochus contained authentic history, whereas anything he may have conjectured beyond that point was false, inasmuch as he would not have foreknown the future.
- Daniel does not belong to the Hebrew Scriptures, since it was composed in Greek
- Nebuchadnezzar, a very proud king, would have never fallen on his face and worshipped Daniel (Dan 2.47)
- The queen, wife of King Belshazzar, knew more about past events than the king, which is absurd (Dan 5.10)
- The events after Dan 11.24, which correspond to the date of the composition of the text, are all wrong
Some of these arguments were easily dismissed as soon as they were made, for example, the argument about the queen being Belshazzar's wife, instead of his mother or grandmother, and of the king worshipping Daniel, instead of the God of Whom Daniel was the voice. The argument about the non-canonicity of Daniel was dismissed when parts of the book were found among the Dead Sea Scrolls. Other arguments required modern techniques, for example, there are modern mathematical models that can date a text based on the language used, and Daniel is not a text that corresponds to the reing of Antiochus, but rather to the time of Babylonian hegemony or the reign of Cyrus the Great. And even if Daniel were written at the time of Antiochus, it still contains some predictions, like the arrival of the Messiah in Jerusalem, and the total destruction of this city, so it would be a very weak argument to suppose that Daniel was false in claiming to be a prediction of events during the reign of Antiochus while being accurate for events that happened about two centuries later.
- The birthday is given in A New and General Biographical Dictionary, where it's also said he lived about seventy years.
- Thomas-Pope Blount, Censura Celebrorum Authorum, p.145 (latin text)
- A New and General Biographical Dictionary, Volume X, p.1 (english text)
- Rev. Robert Lynam, The British Essayists, Volume 23, p.48 (english text)
- Respectively, the Seleucid and Ptolemaic dinasties that ruled these areas after the Empire of Alexander the Great was partitioned among his generals.
- John Erskine, Sketches Ad Hints of Church History, and Theological Controversy, Volume 1, p.187 (english text)
- John King, translator of John Calvin's Calvin's Commentaries, Translator's Preface, Authenticity of the Book of Daniel (english text)
- Jerome, Commentary on Daniel (english text)
- Fragments of every book of the Hebrew Bible (except the Book of Esther) were found in the Qumran caves, the most famous of the Dead Sea Scrolls sites
- See the reference section in the article about the Book of Daniel