A CRITIQUE OF CARTESIAN KNOWABILITY
TROY NUNLEYABSTRACT. Frederick Fitch has provided a proof which seems to demonstrate that if all truths are knowable then all truths are known. In response, some defenders of the view that truth is essentially knowable have sought to avoid this result by restricting the claim that all truths are known in some principled fashion. Neil Tennant has proposed a restriction according to which only “Cartesian” truths are knowable. His opponents, most notably Timothy Williamson, have alleged that the restriction is too strong and trivializes antirealism, effectively reducing it to the uninteresting claim that knowable truths can be known. This article reformulates and defends Williamson’s objection. Additionally, it investigates Tennant’s most recent formulation of “Cartesian- hood” and his contention that it avoids these sorts of objections altogether. It will be shown that the new formulation faces the same criticism and apparent trivialization as previous versions. pp. 121–131
Keywords: Cartesian knowability, truth, antirealism, Fitch, Tennant, Williamson