The ¬K¬K rule and the structurally unknowable

Abstract

Rosenkranz (2021) offered a logic and a detailed account of justification, according to which justification that p can be analyzed as a form of second-level ignorance: ¬K¬Kp. An intuition behind the analysis is that the justified subject has the potential, at least in a nearby world, to either come to know p or come to know ¬Kp. However, given Rosenkranz's hyperintensional semantics for modeling knowledge states, we can always construct, out of an ¬K¬K-agent's knowledge state, epistemic possibilities that prohibit the agent from having that potential. This shows that Rosenkranz's analysis is still insufficient for carrying all the epistemic weight underlying the notion of justification. A better analysis would require a deeper look into an agent's knowledge structure and its involved modalities, which could be a lot more complex than what the ¬K¬K rule tells us.Keywords Justification • Ignorance • The ¬K¬K rule • Rosenkranz • Knowability 1 In this paper, unless specified, I will be exclusively focusing on propositional justification and propositional knowledge in terms of being-in-a-position-to-know.Yiwen Zhan

Replies to critics

“…Consequently, given H2, in (I), one lacks doxastic justification for t in both β 1 and β 2 -and this is hard to reconcile with the assumption that, in (I), one has propositional justification for t in α (cf. my reply to Zhan, 2022).…”

“…Since we are here concerned with challenges to the right-to-left conditional across H1, we also need a dialectically neutral criterion that helps to determine if subjects lack propositional justification. Reliable pre-theoretic intuitions about the lack of propositional justification are hard to come by, if only because propositional justification is a mere potential for doxastic justification and so need not consist in any piece of evidence currently in one's possession (see my reply to Zhan, 2022). Dialectic neutrality doesn't mean theoretical neutrality.…”

“…In his thought-provoking comments (Zhan, 2022), Yiwen Zhan, like Daniel Waxman (2022), targets one of the key theses I advanced in JAI, viz.…”

“…H1* One has propositional justification for believing p iff one might be in a position to know p, where, according to Zhan, 'might' encodes some kind of 'epistemic opportunity' (Zhan, 2022: 2). 26…”

Précis of Justification as Ignorance

“…Even with such an idealization in place, however, (c) and, in particular, (d) may be thought vulnerable to the threat of counterexample. In my reply to Waxman (2022) and Zhan (2022), I detail how formidable such threats may, after all, successfully be averted.…”