Reading through the Jewish apocalypses again, I have found the definition of apocalypse given by the SBL Genre Group back in 1979 to be entirely appropriate. John Collins has been one of the main proponents of this definition, which states that an apocalypse is "a genre of revelatory literature with a narrative framework, in which a revelation is mediated by an otherworldly being to a human recipient, disclosing a transcendent reality which is both temporal, insofar as it envisages eschatological salvation, and spatial insofar as it involves another, supernatural world" (Collins, The Apocalyptic Imagination: An Introduction to Jewish Literature , 2nd ed. 1998, p. 5). There have been a number of suggested additions to the definition, but this is the essential starting point for any discussion of "apocalypse" and therefore also of the adjective "apocalyptic".