 The argument from challenges like  (28)  is surely the least compelling. First, to meet the challenge raised by  (28),  it would be sufficient for the speaker to show that she has good reasons to believe that what she said is true (Lackey 2007: 610; Kvanvig 2009: 143; McKinnon &amp; Turri 2013). It does not seem, by contrast, that the speaker has to prove that she knows (rather than merely believe) that what she said is true. Second, taking the argument seriously proves too much. Consider  (29):