 Like other early modern reformist schemes, Pufendorf’s project faced the central question of method in more specific terms. Initially he followed the example of Weigel, his Cartesian mentor at Jena (whose own Arithmetic Description of Moral Wisdom would appear only in 1674; see Weigel 2003), by employing a quasi-mathematical approach that aspired to demonstrative certitude in moral matters in place of Aristotelian probabilism. Thus, the early EJU (1660) was formally divided into Definitions (Bk.1) and Principles (Bk.2), with the latter subdivided into Axioms and Observations. The truth and necessity of the Axioms flowed directly “from reason itself” and a “bare intuition of the mind,” without the apprehension of particulars, or interpersonal discussion, while the certainty of the Observations was known by the “collation and perception of individual things corresponding to one another,” and by “common sense and experience” (EJU 1999, pp. 6, 117; Dufour 1980, Röd 1970, Bach 2013).