There are 3 parts to this collection.

(1) Against Apion is a two-volume defence of Judaism as classical religion and philosophy, stressing its antiquity, as opposed to what Josephus claimed was the relatively more recent tradition of the Greeks. Some anti-Judean allegations ascribed by Josephus to the Greek writer Apion, and myths accredited to Manetho are also addressed.

(2) Discourse To The Greeks Concerning Hades describes the author's views on the afterlife against the prevailing view of the "Greeks" (i.e., the Greco-Romans) of his day. Although generally still reprinted in editions of Whiston's Josephus, later scholars have realized that this attribution is incorrect. This brief discourse, at least in its original form, is now attributed to the church father Hippolytus.

(3) The Life of Josephus is an autobiographical text written by Josephus in approximately 94-99 CE – possibly as an appendix to his Antiquities of the Jews – where the author for the most part re-visits the events of the War, apparently in response to allegations made against him by Justus of Tiberias. (Summary from Wikipedia)