The knowability paradox threatens metaphysical or semantical antirealism, the view that truth is epistemic, by revealing an awful consequence of the claim [i] that all truths are knowable. Various attempts have been made to find a way out of the paradox.

In the first section of this paper I offer a necessary condition for members of a particular class of arguments to be acceptable asproofs. In the second section, I point out that a plausible extension of this principle reveals that a number of additional arguments cannot function successfully as proofs. Finally, I note that a number of theological arguments, particularly cosmological and ontological arguments, are suspect in the light of this extended principle. Standardly in the ontological argument, criticism falls on (...) the conditional, modality-enriching premise which involves a move from possibility to actuality. I offer two defences of this premise, and argue that—as the use of Moore's extended maxim shows—the problem lies with the premise that asserts mere possibility. (shrink)

I have argued that without an adequate solution to the knower paradox Fitch's Proof is- or at least ought to be-ineffective against verificationism. Of course, in order to follow my suggestion verificationists must maintain that there is currently no adequate solution to the knower paradox, and that the paradox continues to provide prima facie evidence of inconsistent knowledge. By my lights, any glimpse at the literature on paradoxes offers strong support for the first thesis, and any honest, non-dogmatic reflection on (...) the knower paradox provides strong support for the second. Whether verificationists want to go the route I've suggested is not for me todecide. As in the previous section my aim has been that of defending the mere viability of verificationism in the face of what many, many philosophers have taken to be its death-knell, namely Fitch's Proof. But, as the final objection makes clear, showing that verificationism can live in the face of Fitch's Proof is one thing; showing that it should live is another project. If nothing else, I hope that this papershows that verificationists still have a project to pursue; Fitch's Proof, contrary to popular opinion, need not bury verificationism.13. (shrink)