That determinism occupies an integral place within apocalypticism’s notional architecture is routinely acknowledged in scholarship. However, examinations of determinism’s conceptual structure and function within Jewish and early Christian apocalypticism are lacking. Moreover, where determinism has been treated within this context, it is frequently framed by the language and definitional constructs of contemporary philosophical and popular discourse. The effect of this approach is to obscure the conceptual coherence which underlies the texts. In light of this gap in scholarship, I examine determinism and human moral agency within four Jewish historical apocalypses: the biblical book of Daniel chaps. 7-12, The Animal Apocalypse, 4 Ezra, and 2 Baruch. This analysis eschews the framework of contemporary philosophical and popular discourse in an effort to understand the way in which apocalyptic determinism coheres with conceptualizations of human moral agency within the texts themselves. From this analysis, it is my contention that: 1) a stable, conceptual core of an “early Jewish apocalyptic determinism” persists across the four apocalypses, which together correspond to a period of approximately 300 years; 2) 4 Ezra and 2 Baruch reflect two distinct developmental directions for “early Jewish apocalyptic determinism;” and 3) across the four apocalypses, “early Jewish apocalyptic determinism” contributes to the texts’ social function in a consistent manner.