Sibylline Oracles, collection of oracular prophecies in which Jewish or Christian doctrines were allegedly confirmed by a sibyl (legendary Greek prophetess); the prophecies were actually the work of certain Jewish and Christian writers from about 150 bc to about ad 180 and are not to be confused with the Sibylline Books, a much earlier collection of sibylline prophecies (see Sibyl). In the Oracles the sibyl proved her reliability by first “predicting” events that had actually recently occurred; she then predicted future events and set forth doctrines peculiar to Hellenistic Judaism or Christianity. The Jewish apologist Josephus and certain Christian apologists thought the works were the genuine prophecy of the sibyls and were greatly impressed by the way in which their doctrines were confirmed by external testimony. Both Theophilus of Antioch and Clement of Alexandria, 2nd-century Christian theologians, referred to the sibyl as a prophetess apparently no less inspired than the Old Testament prophets.
In the Byzantine period 12 of the compositions were collected in a single manuscript containing 14 books (of which numbers 9 and 10 are lost). An incomplete text of this collection was first published in 1545.
Modern scholars have dated the various Oracles by comparing the actual historical events with what was predicted in the Oracles. At the point where errors begin, the oracle-writer was predicting the future, and it is possible to assign a date from the last correct prediction.