This thesis defines Paul's "indicative-imperative" logic as having the form, 'Since God has done or is doing X for us in particular [indicative], let us do Y in response [imperative].' It then asks whether, or to what extent, one finds the same pattern of reasoning in Scripture and early post-biblical Judaism. Multiple examples from the Jewish sources and from Paul's undisputed letters are cited and analyzed, with a view to a final comparison between the two at the point where each may follow the indicative-imperative logic. In this way, further light is cast on [a] the possible origin of Paul's moral teaching, [b] his place in the history of ideas/ethics, [c] the nature of biblical morality and, more generally, ancient Jewish morality, and [d] the problem of indicative and imperative. Chapter 1 constitutes our introduction. Chapters 2 and 3 deal with the indicative-imperative logic in Scripture and early post-biblical Judaism respectively. Chapter 4 considers Paul's own use of the same framework, while chapter 5 does the comparative work here described, addressing matters [a] through [d] above.