 When concluding his discussion of the example, Kilvington describes Proposition 1 as one “that is true now and that would not be true in virtue of its being in fact as is signified by the positum” (S47, (cc); Kretzmann &amp; Kretzmann 1990b, 131). Kilvington is thus inviting the respondent to think counterfactually when defending a false positum, and as he continues, he applies this to how one ought to answer when evaluating a sophisma. One ought to grant what would be true and deny what would be false, given the positum.