Factive Presupposition and the Truth Condition on Knowledge

In “The Myth of Factive Verbs” (Hazlett 2010), I had four closely related goals. The first (pp. 497-99, p. 522) was to criticize appeals to ordinary language in epistemology. The second (p. 499) was to criticize the argument that truth is a necessary condition on knowledge because “knows” is factive. The third (pp. 507-19) – which was the intended means of achieving the first two – was to defend a semantics for “knows” on which <S knows p> can be true even if p isn’t true. The fourth (Ibid.) – which seemed necessary for the success of the third – was to defend a pragmatic account of the fact that utterances of <S knows p> typically imply p, on which the implication in those cases is down to conversational implicature. In this paper I’ll go after these goals again, with an emphasis on the second. Our topic will be whether the factivity of “knows” (whatever this amounts to) supports the truth condition on knowledge. A new goal will be to defend my argument against some criticisms from John Turri (2011) and Savas Tsohatzidis (forthcoming). We’ll first look at the truth condition (§1) and factive presupposition (§§2 – 3), before turning to replies to Turri and Tsohatzidis (§§4 – 7).