 Boethius regarded the Stoic interpretation of Aristotle’s view as mistaken, his interpretation being based on the terms ‘definitely’ true or false and ‘indefinitely’ true or false. These same terms were also used in Ammonius’s commentary (c. 435/445–517/526). Since this work was not known to Boethius, both authors seem to have known some earlier Greek discussions in which these qualifications were introduced. (Ammonius’s Greek commentary on De interpretatione 9 is translated by D. Blank and Boethius’s Latin commentaries by N. Kretzmann in the same volume, with interpretative essays by R. Sorabji, N. Kretzmann and M. Mignucci in 1998.) The contemporary reconstructions of what Ammonius and Boethius meant can be divided into two groups. According to one interpretation, Ammonius and Boethius ascribe to Aristotle the view that the predictions of future contingent events and their denials differ from other contradictory pairs, because truth and falsity are not definitely distributed between them and the propositions are consequently neither definitely true nor definitely false. In answering the Stoic criticism, Boethius might have thought that future contingent propositions have the disjunctive property of being true-or-false, which would mean something other than simply lacking a truth value. (For various interpretations of how Boethius restricted bivalence, see Frede 1985; Craig 1988; Gaskin 1995; Kretzmann 1998.) Another interpretation holds that Boethian future contingents are not definitely true or false because their truth-makers are not yet determined, but are true or false in an indeterminate way. No qualification of the principle of bivalence is involved. True statements are either definitely true or simply (indefinitely) true or false (Mignucci 1988, 1998; Seel 2000; Beets 2003 for Boethius’s first commentary). According to both interpretations, Ammonius and Boethius assumed that the definite truth of predictions directly implies determinism and that Aristotle denied the definite truth of all future contingent propositions; it is less clear how they understood the indefinite truth of these (Sorabji 1998a). Boethius’s formulations often suggest that future contingent propositions are true-or-false. An additional reason for not treating them as simply true or false is his view of the necessity of the present. In commenting on Aristotle’s remark that “ what is necessarily is when it is” (De interpretatione 19a23), Boethius explains that even though present things are temporally or conditionally necessary, they may be generically or antecedently contingent (In Perihermeneias I, 121.20–122.4; II, 241.7–243.28). He apparently thinks that the truth of future contingent statements implies that things cannot be otherwise, for the assumed actuality of the relevant future truth-makers means that alternative diachronic prospectives are rendered temporally impossible. 