Impurism says that practical factors encroach on knowledge. An important version of impurism is called ‘Threshold-Impurism,’ which says that practical factors encroach on the threshold that rational credence must pass in order for one to have knowledge. A prominent kind of argument for Threshold-Impurism is the so-called ‘principle-based argument,’ which relies on a principle of fallibilism and a knowledge-action principle. This paper offers a new challenge against Threshold-Impurism. I attempt to show that the two principles Threshold-Impurists are committed to—KJ and (...) Fallibilism—are jointly in tension with a widely-held principle of credence that’s called ‘Truth-Directedness,’ in the sense that the former two principles cannot both apply to those who know the third. This tension constitutes a serious challenge to Threshold-Impurists, because it leaves them two options, both of which are undesirable: denying Truth-Directedness, or accepting Truth-Directedness and accepting that whether KJ and Fallibilism apply to a person depends on whether she knows Truth-Directedness. (shrink)

Impurism says that practical factors encroach on knowledge. An important version of impurism is called ‘Threshold-Impurism,’ which says that practical factors encroach on the threshold that rational credence must pass in order for one to have knowledge. A prominent kind of argument for Threshold-Impurism is the so-called ‘principle-based argument,’ which relies on a principle of fallibilism and a knowledge-action principle. This paper offers a new challenge against Threshold-Impur- ism. I attempt to show that the two principles Threshold-Impurists are committed to—KJ (...) and Fallibilism—are jointly in tension with a widely-held principle of credence that’s called ‘Truth-Directedness,’ in the sense that the former two principles cannot both apply to those who know the third. This tension constitutes a serious challenge to Threshold-Impurists, because it leaves them two options, both of which are undesirable: denying Truth-Directedness, or accepting Truth-Directedness and accepting that whether KJ and Fallibilism apply to a person depends on whether she knows Truth-Directedness. (shrink)

You receive a pink packet from Miss Lead, a notoriously deceptive truth-teller. You know that if you open the packet and do not find blank pages, then you will justifiably change your mind about the evidence being misleading. Indeed, you will infer that your previous fears about misleading evidence were themselves founded on misleading evidence. Should you open the pink packet? No, answers an advocate of self-censorship. Yes, answers an advocate of the principle that you should base conclusions on all (...) the available evidence. Your final deliberations will be guided by Gilbert Harman’s Thought. Ultimately, the case against opening the packet prevails. (shrink)

To qualify as a fully rational agent, one must be able rationally to revise one’s beliefs in the light of new evidence. This requires, not only that one revise one’s beliefs in the right way, but also that one do so as a result of appreciating the evidence on the basis of which one is changing one’s mind. However, the very nature of belief seems to pose an obstacle to the possibility of satisfying this requirement – for, insofar as one (...) believes that p, any evidence that not-p will strike one as misleading and, on the face of it, believing that a certain piece of evidence is misleading is incompatible with appreciating the fact that such evidence should bear on the question at hand. Call this the ‘Paradox of Belief Revision’. This paper introduces the Paradox of Belief Revision, compares it with Kripke’s Dogmatism Paradox, and suggests that we may be able to see a way out of the former if we assume that rational agents are systematically aware of their own beliefs as beliefs they have. (shrink)

The standard conception of misleading evidence has it that e is misleading evidence that p iff e is evidence that p and p is false. I argue that this conception yields incorrect verdicts when we consider what it is for evidence to be misleading with respect to questions like whether p. Instead, we should adopt a conception of misleading evidence according to which e is misleading with respect to a question only if e is in-fact irrelevant to that question – (...) a relation that requires that e fail to be both explanatorily connected to and evidence for any truth that answers the question. This modified conception allows e to be non-misleading evidence with respect to a question even if e is evidence for the false answer to that question. It also points toward a new argument for and explanation of the truth of a central premise – what Maria Lasonen-Aarnio dubs “Entitlement” – that generates the infamous dogmatism puzzle. (shrink)