Virtually all epistemologists agree that truth is a necessary condition for knowledge. Assuming that our three-dimensional world is nested within a higher-dimensional space, I use multidimensional geometry to present a type of case which undermines this fundamental principle of epistemology. I further argue that we would be unlikely to revise our epistemic practices in light of new discoveries even if our world turned out to be substantially different and many of our beliefs turned out to be false.

In “The Myth of Factive Verbs” (Hazlett 2010), I had four closely related goals. The first (pp. 497-99, p. 522) was to criticize appeals to ordinary language in epistemology. The second (p. 499) was to criticize the argument that truth is a necessary condition on knowledge because “knows” is factive. The third (pp. 507-19) – which was the intended means of achieving the first two – was to defend a semantics for “knows” on which <S knows p> can be true (...) even if p isn’t true. The fourth (Ibid.) – which seemed necessary for the success of the third – was to defend a pragmatic account of the fact that utterances of <S knows p> typically imply p, on which the implication in those cases is down to conversational implicature. In this paper I’ll go after these goals again, with an emphasis on the second. Our topic will be whether the factivity of “knows” (whatever this amounts to) supports the truth condition on knowledge. A new goal will be to defend my argument against some criticisms from John Turri (2011) and Savas Tsohatzidis (forthcoming). We’ll first look at the truth condition (§1) and factive presupposition (§§2 – 3), before turning to replies to Turri and Tsohatzidis (§§4 – 7). (shrink)

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)

In his Knowledge and Belief (1962), Hintikka establishes his system of epistemic logic with the KK (Knowing that One Knows, in symbols, Kp→KKp) principle (KK for short). However, his system of epistemic logic and the KK principle are grounded upon his strong notion of knowledge, which requires that knowledge is infallible, that is, it makes further inquiry pointless, and becomes ‘discussion-stopper’; knowledge implies truth, to wit, cognitive agents will not be mistaken in their knowledge; cognitive agents will be ‘perfect logicians’, (...) i.e. they have infinitive capability of logical inference. Hintikka calls the argument for KK from the strong notion of knowledge as the ‘transcendental argument’ for KK. Obviously, the strong notion of knowledge is far away from our ordinary conception of knowledge; based on such a strong sense of knowledge, epistemic logic has met the problem of logical omnipotence, and is difficult to apply in our ordinary cognitive practice. Moreover, there is no close connection of the KK principle with internalism or externalism. (shrink)

The goal of this paper is to explore the presuppositionality of factive verbs, with special emphasis on the verbs know and regret. The hypothesis put forward here is that the factivity related to know and the factivity related to regret are two different phenomena, as the former is a semantic implication that is licensed by the conventional meaning of know, while the latter is a purely pragmatic phenomenon that arises conversationally. More specifically, it is argued that know is factive in (...) the sense that it both entails and presupposes p, while regret is factive in the sense that it only presupposes p. In a recent article, Hazlett, 497–522, 2010) shows with authentic examples how know is used non-factively in ordinary language, and he observes in these examples, as he says, “a threat to Factivity.” I argue that non-factive uses of factive verbs, such as know and regret, far from being a threat to factivity, show that, on the one hand, know is ambiguous between a factive and a non-factive sense; on the other hand, in the case of regret, the presupposition of factivity has to be intended as a merely pragmatic implication which can be suspended by the speaker herself. (shrink)

I develop a challenge for a widely suggested knowledge-first account of belief that turns, primarily, on unknowable propositions. I consider and reject several responses to my challenge and sketch a new knowledge-first account of belief that avoids it.