Contextualism in epistemology is the doctrine that the proposition expressed by a knowledge attribution relative to a context is determined in part by the standards of justification salient in that context. The (non-skeptical) contextualist allows that in some context c, a speaker may truly attribute knowledge at a time of a proposition p to Hannah, despite her possession of only weak inductive evidence for the truth of that proposition. Relative to another context, someone may make the very same knowledge attribution (...) to Hannah, yet be speaking falsely, because the epistemic standards in that context are higher. The reason this is possible, according to the contextualist, is that the two knowledge attributions express different propositions. (shrink)

Keith DeRose gives an invalid argument for contextualism in “Assertion, Knowledge, and Context.” In section 2.4, entitled “The Argument for Contextualism,” DeRose makes the following remarks. “The knowledge account of assertion provides a powerful argument for contextualism: If the standards for when one is in a position to warrantedly assert that P are the same as those that comprise a truth-condition for ‘I know P,’ then if the former vary with context, so do the latter. In short: The knowledge account (...) of assertion together with the context-sensitivity of assertability yields contextualism about knowledge”. (shrink)

Thomas Blackson does not question that my argument in section 2 of “Assertion, Knowledge and Context” establishes the conclusion that the standards that comprise a truth-condition for “I know that P” vary with context, but does claim that this does not suffice to validly demonstrate the truth of contextualism, because this variance in standards can be handled by what we will here call Subject-Sensitive Invariantism (SSI), and so does not demand a contextualist treatment. According to SSI, the varying standards that (...) comprise a truth-condition of “I know that P” are sensitive to factors that attach to the speaker as the putative subject of knowledge, rather than as the speaker of the knowledge attribution. That is, according to SSI, these factors of the subject’s context determine a single set of standards that govern when the subject himself, or any other speaker, including those not engaged in conversation with the subject, can truthfully say that the subject “knows.” Thus, we do not get the result that contextualists insist on: that one speaker can truthfully say the subject “knows,” while another speaker, in a different and more demanding context, can say that the subject does “not know”, even though the two speakers are speaking of the same subject knowing (or not knowing) the same proposition at the same time. Given the possibility of SSI, Blackson concludes that I “either assumed without argument that [SSI] is false or failed to distinguish the different ways the standard for knowledge might be determined.” I indeed have long assumed that SSI can’t be right, and so have taken a different form of invariantism to be the real threat to contextualism. But since SSI, and views like it, now seem to be getting considerable attention, it is worth articulating why I find it unpromising. (shrink)