To earn respect, a genre of Jewish texts assigns authorship to biblical figures and sages of previous eras.
Writing under a pseudonym usually protects the identity of the author, but pseudepigraphy is more like identity theft. By attributing one's works to an earlier, well-known character, the pseudepigrapher not only establishes a narrative setting for the work, but also imbues the text with added authority. In Jewish literary history, most pseudepigraphs provide that authority for works of an apocalyptic or mystical nature. This article was written by Jeffrey Spitzer. Really. I promise.
In a literary culture that asserts that everything of worth was already revealed by God to Moses (Talmud Yerushalmi Peah 2:4), little room is made for originality. That, ultimately, is the reason that Jews who wanted other Jews to pay attention to their highly original work frequently attributed their works to people of great antiquity, establishing the custom of Jewish pseudepigraphy or false attribution.
Much of Jewish pseudepigraphy either draws on Jewish mysticism or comes from circles that had an emphasis on mystical speculation and experience. This is not really surprising; the kinds of "original works" that would need the added "authority" of an early author were frequently speculative and included claims of divine revelation or extraordinary authority. The term "the Pseudepigrapha" is a scholarly category referring to works roughly from the Second Temple period (sixth century BCE-first century CE), most of which are falsely attributed to biblical characters, and most of which include prophetic or mystical revelations.
The last half of the biblical book of Daniel was already identified in the third century CE as being a pseudepigraph. This part of the book retells what are purported to be revelations of future events during the second century BCE with uncanny accuracy, until the events of winter 164, during the reign of Antiochus Epiphanes IV. In the words of the pagan philosopher Porphyry, who identified Daniel as pseudepigraphic (as quoted by the Church Father Jerome), "[Daniel] was composed by someone who lived in Judea in the reign of Antiochus Epiphanes, and he did not foretell the future but retold the past. Therefore, what he says down to Antiochus is accurate history; but if he added any guesses about the future, he just invented them, for he did not know the future."
Other pseudepigraphs from the Second Temple period include the book of Jubilees, which presents itself as a dialogue between the Angel of God's Presence and Moses and includes retellings of biblical narratives as well as rather strict "clarifications" of biblical law. The Testaments of the Twelve Patriarchs and other Testaments take the literary form of deathbed stories, but frequently include legendary material as well as mystical content. Many of the pseudepigraphic works of this period, however, are attributed to less prominent Biblical characters. Enoch, whose report of death is quite unusual ("[Enoch] walked with God; then he was no more," Genesis 5:23) became a natural target for mystical books dealing with ascents to heaven. Barukh, the scribe who worked for the prophet Jeremiah, must have written something of his own. A pseudepigrapher filled out Barukh's resumé by penning, under his name, an apocalyptic vision set during the fall of the First Temple.