Nearly all philosophers agree that only true things can be known. But does this principle reflect actual patterns of ordinary usage? Several examples in ordinary language seem to show that ‘know’ is literally used non-factively. By contrast, this paper reports five experiments utilizing explicit paraphrasing tasks, which suggest that non-factive uses are actually not literal. Instead, they are better explained by a phenomenon known as protagonist projection. It is argued that armchair philosophical orthodoxy regarding the truth requirement for knowledge withstands (...) current empirical scrutiny. (shrink)

We propose a Bayesian framework for the attribution of knowledge, and apply this framework to generate novel predictions about knowledge attribution for different types of “Gettier cases”, in which an agent is led to a justified true belief yet has made erroneous assumptions. We tested these predictions using a paradigm based on semantic integration. We coded the frequencies with which participants falsely recalled the word “thought” as “knew” (or a near synonym), yielding an implicit measure of conceptual activation. Our experiments (...) confirmed the predictions of our Bayesian account of knowledge attribution across three experiments. We found that Gettier cases due to counterfeit objects were not treated as knowledge (Experiment 1), but those due to intentionally-replaced evidence were (Experiment 2). Our findings are not well explained by an alternative account focused only on luck, because accidentally-replaced evidence activated the knowledge concept more strongly than did similar false belief cases (Experiment 3). We observed a consistent pattern of results across a number of different vignettes that varied the quality and type of evidence available to agents, the relative stakes involved, and surface details of content. Accordingly, the present findings establish basic phenomena surrounding people’s knowledge attributions in Gettier cases, and provide explanations of these phenomena within a Bayesian framework. (shrink)